Frequently Asked Questions
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Why can't I put a 25C-to-5C adapter on my machine?
The draw bar force on an A2-8 spindle is too great for a 5C collet. It would rip the threads off the collet.
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Category: 25C Collets
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Why do you ask me if I want internal threads on a 5C collet over 1"?
Because the collet is approaching its maximum capacity, there is not enough room in the collet for both a through hole and internal threads. If you will be using a bar feed, you will need to use one without internal threads. If you are using a stop in chucking applications, you will need one with threads.
5C collets with internal threads have a stepped hole. The depth of the step depends on the size of the hole. From 1-1/16" to 1-1/8", it will be stepped only.
Is there an adapter that allows me to use my 5C Collets in the 16C Spindle?
Yes, there is a 16C-to-5C collet adapter which accepts 5C collets. This is a good purchase if you have many 5C collets and few 16C, but there are limitations. The major one is concentricity. Because of the number of parts in the assembly, the TIR is greater than .002". It also takes about 15 minutes to change a collet with this adapter. Adapters are available for 20C-to-16C or 25C-to-16C.
Which collets and feed fingers are standard for #00 & #00G machines?
The #00 Collet (Part #3003), the #00 Feed Finger for 5/16" Capacity Tube (Part #3009), the #00A Feed Finger for 3/8" Capacity Tube (Part #3011) are typical.
Also standard are the #10 Collet (Part #3033), the #10 Finger for 3/8" Capacity Tube (Part #3035), and the #10A Finger for 1/2" Capacity Tube (Part #3037) are also typical.
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Category: Brown & Sharpe
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Which collets and feed fingers are standard for #00 Automatic machines with 3/4" Capacity?
The #11C Collet (Part #3071) and the #10AA Finger for 3/4" Capacity Tube (Part #3039) are typical.
If using alternate chuck sleeves, use the #11 Collet (Part #3057). If using alternate adapters, use the #10 or #10A Fingers (Part #3035 or #3037).
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Category: Brown & Sharpe
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Which collets and feed fingers are standard for #0 and #0G Automatics?
The #11 Collet (Part #3057), the #11 Finger for 1/2" Capacity Tube (Part #3061), the #11A Finger for 5/8" Capacity Tube (Part #3063), and the #11B Finger (Part #MP-1727, which is a special) are typical.
When using the Outside Feeding Attachment, use the #11C Collet (Part #3071) and the #21A Finger for 3/4" Capacity Tube (Part #3095).
With a chuck nut for Taper-Nose collets, use the #11B Collets (Part #MP1727).
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Category: Brown & Sharpe
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Which collets and feed fingers are standard for #2 and #2G Automatics?
The #22 Collet (Part #3111), the #22 Finger for 1" Capacity Tube (Part #3115), the #22B Collet (Part #3121), and the #22A Finger for 1-1/8" Capacity Tube (Part #3119) are typical.
When using the Outside Feeding Attachment: use #22A Collet for 1-5/16" spindle (Part #3117), #22B Collet for 1-7/16" spindle (Part #3121), #22B Finger for 1-3/8" Capacity Tube (Part #MP1557, which is a special), #22C Collet (Part #3125), #22H Finger for 1-1/4" Capacity Tube (Part #3133), #22D Collet (Part #3127), and #22D Finger for 1-1/2" Capacity Tube (Part #3129).
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Category: Brown & Sharpe
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Which collets and feed fingers are standard for #2 Ultramatic with 1-5/8" Capacity?
The #22D Collet (Part #3127), the #22DD Finger for 1-5/8" Capacity Tube (Part #3131) are typical.
With alternate chuck sleeves, use the #11 (Part #3057), or #11C (Part #3071), or #22 (Part #3111), or the #22C (Part #3125) Collets.
With alternate adapters, use the #10 (Part #3035), or #11AA (Part #3065), or #22 (Part #3111), or #22H (Part #3133), or the #22D (Part #3129) Feed Fingers.
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Category: Brown & Sharpe
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Which collets and feed fingers are standard for #3 Ultramatic with 2-3/8" Capacity?
The #23 (Part #3153) Collet, or the #23A (Part #3147) Collet; the #23 (Part #3153) Finger for 2" Capacity Tube, #23M (Part #3149) Master Collet and Pads, and the #23M Master Finger and Pads are typical. From sizes 2" to 2-3/8" inclusive, an Outside Feeding Attachment and Stock Loader are used.
With alternate chuck sleeves, use the #22 (Part #3111), #22C (Part #3125) or the #22D (Part #3127) Collets.
With alternate adapters, use the #10 (Part #3035), #11AA (Part #3065), #22 (Part #3115), #22H (Part #3133), or #22D (Part #3129) Fingers.
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Category: Brown & Sharpe
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Which collets and feed fingers are standard for #4 Automatic with 1-7/8" Capacity?
The #24 (Part #MP1133, which is special) Collet, the #24 (Part #3169) finger, the #24M (Part #3171) Master Collet and Pads, and the #24M (Part #3173) Master Finger and Pads are typical.
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Category: Brown & Sharpe
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Which collets and feed fingers are standard for #6 Automatic and #4 Automatic with 2-3/8" Capacity
The #26 (Part #3187) Collet, the #26 (Part #3191) Finger, the #26M (Part #3193) Master Collet and Pads, and the #26M (Part #3189) Master Finger and Pads are typical.
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Category: Brown & Sharpe
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Which collets and feed finger are standard for #0 Wire Feed Screw Machine?
The #10 (Part #3033) Collet, the #10 (Part #3035) Finger for 3/8" Capacity Tube machines are typical.
The #10B (Part #MP2330, which is special) Collet and the #11A (Part #3063) Finger for 5/8" Capacity Tube machines are typical.
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Category: Brown & Sharpe
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Which collets and feed finger are standard for #1 Wire Feed Screw Machine?
The #11 (Part #3057) Collet and the #11 (Part #3061) Finger for 1/2" Capacity Tube are typical.
The #21 (Part #3089) Collet, the #21 (Part #3093) Finger for 5/8" Capacity Tube and the #21A (Part #3095) Finger for 3/4" Capacity Tube are typical.
The #21 (Part #3089) Collet and the #21 (Part #3093) Finger for 7/8" Capacity Tube are typical.
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Category: Brown & Sharpe
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Which collets and feed finger are standard for #2 Wire Feed Screw Machine?
The #22 (Part #3111) Collet and the #22 (Part #3115) Finger for 1" Capacity Tube machines are typical.
The #22B (Part #3121) Collet and the #22A (Part #3119) Finger for 1-1/8" Capacity Tube machines are typical.
The #22C (Part #3125) Collet and the #22H (Part #3133) Finger for 1-1/4" Capacity Tube machines are typical.
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Category: Brown & Sharpe
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Which Style B Hardinge pads compare to Brown & Sharpe Style Pads?
B&S Style 00M uses the Hardinge B1 Style (Part #6601)
B&S Style 10M uses the Hardinge B10 Style (Part #6643)
B&S Style 10AM uses the Hardinge B10AM Style (Part #6649)
B&S Style 11M uses the Hardinge B3 Style (Part #6611)
B&S Style 11AM uses the Hardinge B11 Style (Part #6653)
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Category: Brown & Sharpe
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What's the advantage of buying a collet kit?
Hardinge offers several different kits for various types of collets. For example, the 5C, 16C, 20C, and 25C collets are all available in kits of varying quantities.
The advantage is that you'll have every major size available to you for any job that may come to you. And as an incentive to you, we price the kits so that the total cost of the kit is 5% less than if you bought the pieces individually. Why not buy a set for your tool room today?
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Category: Collet Kits
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Will threaded collet stops help me hold lengths?
If the diameter of the part being gripped is held to a very close tolerance, the answer is yes. Unfortunately, the stop is attached to the collet, which draws back with the draw bar. For every .001" variation in the chucking diameter, the collet will draw back or stick out .003". The main purpose of a collet stop is to eliminate the push-back of the part while it is being machined, or to automatically eject the part when the collet is opened.
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Category: Collet Stops
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I am trying to drill a very accurate hole using a DA-style collet system without any success. Any suggestions?
Here are several things to consider. Extremely accurate drilling requires a very good holder and collet. With the considerable flexibility of the DA, TG, and ER Collets, we tend to forget the cardinal rule for collets: the bore of the collet should be the exact size of the diameter being gripped for the best TIR and gripping force. Therefore, for extremely accurate drilling, the collet bore should be the same size as the shank of the drill.
Second, if you have a choice of holders, it is best to use the ER collet holder over the DA collet holder. The DA holder is a double-angle holder, with a closing angle on the front and back of the collet. The theory is that the collet will close parallel to the centerline of the holder. Unfortunately, it is very difficult to manufacture a holder and collet that accurately mate. For standard drilling tolerances, this usually is not a problem, but can be when doing extremely close tolerance drilling.
The ER is considered a single-angle collet because the major closing angle is long and shallow. This results in better concentricity than the double-angle system.
The TG collet system is better than the ER system because it has an even shallower closing angle. Unfortunately, this system is usually for larger shanks and most holders that use these collets are for vertical machining centers.
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Category: DA-Style Collets
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I turn the closer to bring the back face of the collet flush with the spindle. Do I secure the closer at this point or should I continue to turn the closer another turn or two?
Once the collet is flush to the face of the spindle, turn the closer another 1/2 turn before securing it. This will give you enough spring tension to hold the collet against the face of the spindle when the collet is opened to remove the finished part.
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Category: Dead Length Collets
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What is the proper method for tightening the closer?
While tightening the closer, observe at what point the back face of the collet touches the face of the spindle. Once it touches, you should be able to turn the closer approximately a half turn more (this additional amount sets the spring pressure to hold the collet against the face of the spindle). If you are firmly gripping the part when you touch the spindle, the collet will come away from the face of the spindle when the collet opens, allowing chips and dirt in. This will affect your ability to hold lengths.
If this happens, put pins in the collet, set the closer properly and rebore the collet.
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Category: Dead Length Collets
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Chips are getting between the back face of the collet and the spindle. How do I eliminate this problem?
Your problem is either loose parts in the collet assembly, the spring setting is not right, or the collet closer was not adjusted to hold the collet against the spindle face.
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Category: Dead Length Collets
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Why do I need Dead-Length Collets or Step Chucks?
All draw-in collets have a diameter-to-length ratio when doing secondary operations. When using collets with a 10° head angle, the ratio is 1:3. For every .001" change on the chucking diameter, the part will either pull back .003" or stick out .003" from the setup part. This can mean a total length variation of .009" when the chucking diameter varies .003". If the print calls for a length tolerance less than .002", a standard collet cannot be used. This is where the Dead-Length collet or step chuck fits in. If the stock diameter varies .003", the finished part lengths will not vary more than a few ten thousands (.0002" to .0005").
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Category: Dead Length Collets
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What is the difference between the Dead-Length Collet and Dead-Length Spider-Stop Step Chucks?
The Dead-Length Collet uses the face of the spindle as its locating surface for the inner collet. Because the spindle doesn't move when the draw bar pulls the collet back, the inner collet also doesn't move, resulting in length control. The Dead-Length Spider-Stop Step Chuck uses a spider stop that fits inside the slots of the step chuck and locates against the collet seat (angle) of the spindle. Because the collet seat doesn't move when the draw bar pulls back the step chuck, neither does the spider stop.
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Category: Dead Length Collets
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Is there a time when I would use a Dead-Length Spider-Stop Step Chuck for small diameter work?
Yes. Occasionally a customer finds that the standard 5C Dead-Length Collet does not allow them to hold their parts to the print's concentricity requirements. A Dead-Length Collet does not run as concentric as a hardened and ground collet even though it may be bored in place. This is because of the allowances between the moving parts. A Dead-Length Spider Step Chuck is identical to a standard collet, there is only one moving part - the step chuck. This attribute will allow closer concentricities between chucking and machined diameters than with a standard Dead-Length collet.
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Category: Dead Length Collets
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The pins that I have are shorter than the drilled holes in the face of the collet. Should they be seated in the bottom of the holes?
Pins that come with the collet should seat in the bottom of the hole and be flush with the face or slightly protruding. If the original pins have been machined and/or are short, they should be positioned flush to the face of the collet and not seated in the bottom of the drilled hole.
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Category: Emergency Collets
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Do I need a relief in the bottom of my step collet?
If your part has a large radius or chamfer, a relief is not necessary.
If there is no large corner break on the part, or its condition is unknown, put a relief in the step.
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Category: Emergency Collets
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Do I use the same gripping force to bore out the collet or step chuck that I use to grip the actual part?
You should use just enough pressure to securely hold the pins in place. If you use too much force, the collet will be distorted. This distortion may result in an incomplete bearing on the chucking diameter and may also cause excessive runout.
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Category: Emergency Collets
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After using my collet for a while, I can no longer get the part in when the collet is open. Why?
The collet is worn out. The collet has been opened and closed too many times. The Emergency collet maximum production before wearing out is 250 to 500 pieces.
You may also have accidentally closed the collet without a part in the bore. This will instantly collapse the collet, removing all the spread and distorting the collet beyond use.
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Category: Emergency Collets
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How can I make certain that the collet has the best TIR possible?
Bore it in place. Finish bore it on the machine tool that is going to produce the part. The collet can be roughed on another machine but it must be finished on the machine producing the part.
Only take from .002" to .003" of material on your finish pass. Use a carbide tool with positive rake, small radius and low microinch finish. This results in minimum tool pressure and ensures an excellent finish.
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Category: Emergency Collets
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What is the correct procedure for boring out an emergency collet?
Insert the collet in the spindle with the draw bar in the full open position. Make certain that all the pins are in the face of the collet or step chuck. Adjust the collet closer until closed on the pins and then back off 1/8 to 1/4 of a turn. Do not back off enough to where the collet angle is not fully seated in the spindle. Lock the draw bar in this position.
Decrease the chucking force as much as possible (do not use the same force you would to grip the part). Close the collet. If you can pull the pins out, you should increase the chucking pressure until the pins cannot be removed. Rough and finish the bore to the chucking diameter of the part. Remove the collet and debur it. Thoroughly clean the spindle and then remount the collet. Adjust collet closer for proper gripping and the correct draw bar pressure to hold the workpiece.
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Category: Emergency Collets
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The parts locates against the bottom of the step in my emergency collet. How do I cure this problem?
Skim cut the bottom face of the step chuck.
Take a light skim cut on the bottom face of the step chuck. Make certain you use the pins in the collet and reduce your chucking pressure. Its also a good idea to remove the collet or step chuck and clean the head angle and seat of any chips or dirt.
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Category: Emergency Collets
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I've tried rigid tapping using standard ER collets in my non-floating holders and I'm breaking taps. Why is this happening?
Your maching tool may not be designed for rigid tapping, you did not buy that option, or there is a small error between the spindle reversal and slide reversal. These are machine tool problems and you can work around them without disassembling the machine. Use a floating tap collet such as the ERQC or the ERTC. These collets fit in the standard rigid holder and will float longitudinally.
If you want to continue to use your current collets, floating tap holders are available. These holders are longer than the standard holders and more expensive than the floating tap collets.
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Category: ER-Style Collets
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The TIR of the drill being held in my ER collet is excessive. What TIR can I expect from a standard ER collet?
The quick fix is if you are using a ball bearing cap on your ER holder, change it to a one-piece cap. The ball bearing cap allows you to use more torque when gripping solid floating tap collets, but, when used for drilling, the TIR is not as accurate as the one-piece cap.
All of our ER collets are made to the DIN6499 specification. When checking the collet and holder, use a certified gauge plug. First, indicate the seat of the holder, then assemble collet and gauge plug and indicate the plug at the "L" dimension. Make corrections for holder seat runout (the most accurate check is to use a coordinate measuring system; most indicators do not give a true reading when rotating 360° from the lathe spindle). If this checks out within specifications, check the gauge pin at the actual drill length, which may be longer than the "L" dimension. If the TIR at this point is too great, you will have to acquire a higher precision collet such as the ERNC. If you're using a metric bushing to hold a fractional drill, a more reasonable solution would be to acquire an inch series collet for the exact shank of your drill.
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Category: ER-Style Collets
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I'm using an ER-style collet in a high-speed spindle and am getting vibration that I don't get with my other holders. What's wrong?
You're probably using a standard one-piece cap. Acquire a one-piece cap which has a ring to hold the collet instead of the standard cap which has an eccentric slot. The eccentricity of the groove will cause an out-of-balance condition at high rpm. If this does not eliminate the vibration, the complete assembly will have to be precision balanced in relation to the RPM you're running.
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Category: ER-Style Collets
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I have a part that requires internal gripping. What are my options?
There are two options--the "Master Expanding Collet" and the "Sure-Grip Collet-Style Expanding Collet". Both of these can be used in a 5C or 16C spindle.
The Master Expanding Collet uses interchangeable pads which can be removed and stored. This unit is opened with a draw plug that actuates the collet in the front. It is mainly for light duty machining.
The Sure-Grip Collet-Style Expanding Collet system will also work. The collets are parallel opening and have a range of .125" to 4". This system, in larger sizes, can handle heavy duty machining operations.
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Category: Expanding Collets
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Why not buy a Bargain Collet?
A bargain is possible because something has been compromised. The head angle and bore are not in the 60+ Rockwell range. The back bearing of the collet is not held to precision size and concentricity tolerances. The bore, head angle, back bearing and thread are not all concentric with each other. Because the collet is softer than a Hardinge collet, it will wear very quickly. A precision hardened and ground collet can last for years.
When should I use an emergency collet?
The emergency collet is a life saver. Its used when you need a collet bore to run as close as the spindle's TIR because it is bored in place in the machine's spindle. Its also used when you only have a few hundred parts to run and you don't have the proper size hardened and ground collet. Remember that the head angle and the collet bore are not heat treated on emergency collets and will wear quickly under heavy or long use. The rule of thumb for the life of the bore and leaf tension of an emergency collet is 300 to 500 pieces. The threads are heat treated but the leaves of the collet are not spring tempered. This results in the collet leaves losing their elasticity. Eventually you will not be able to put the part in the collet because the leaves have lost their tension.
I have noticed that the threads and back bearing on the collets are being damaged and have to be replaced. What's wrong?
Vises, Vise-Grips and pump pliers are the cause of your problem. Purchase several Collet wrenches for each style collet in your shop (5C, 16C, 20C, etc.). This wrench is keyed and locates over the back bearing of the collet to hold it while the threaded stop, Dead-Length assembly, etc. are being tightened into the collet.
Why buy a Hardened & Ground Collet?
These collets have a head angle and bore that are case hardened to 60 - 63 Rockwell. They will give you the maximum life possible. The bore is precision ground and guaranteed to have a TIR of .001" or less. Special accuracy collets are available that are guaranteed to have a TIR of .0002". Before investing in a special accuracy collet, check your standard collet - they usually have a TIR of .0005" or better.
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Category: Hardened & Ground
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What is the operating range of a Quick-Change Collet?
The operating range is ±1/64" (.393mm) when used on multi-spindle automatics for bar stock work. The operating range of the collets when used on CNC lathes is -1/64" to +.008" (.20 mm). Note that the best grip is with a full bearing, which is at the rated size of the collet. As the stock gets larger, the collet will grip at the edges of the slots; as the stock gets smaller, gripping will be at the center of the gripping surface.
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Category: HQC Hardinge Quick-Change Collet System
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Do I need to lubricate the Quick-Change Collet?
Yes. We suggest using Dow Corning BR-2+ or Kluber Altemp Q NB 50 grease on both the collet seat in the spindle or spindle mount and the outside diameter of the collet. This should be repeated every 8 hours.
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Category: HQC Hardinge Quick-Change Collet System
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We continually have breakage of closer fingers and pins. Will this continue with Quick-Change?
Considerably less breakage is what our customers tell us when the HQC System is used on automatic screw machines. This is a result of being able to use less force to hold the bar. Because there is no shank on the collet, less draw bar force is required for the same gripping force. Because the collet can handle a wide chucking range, you won't have to change collets when the stock varies or overtighten your closing mechanism.
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Category: HQC Hardinge Quick-Change Collet System
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I machine a lot of short parts. Are there problems short chucking with Quick-Change collets?
When gripping parts that are longer than 1/2 the length of the bearing of the collet, you should have no problems. You may experience problems when your parts are shorter. Because the collet does not have a shank, it will have a tendency to collapse in the back when there is no stock to grip on. Gripping a part that is only 1/4" long will be very difficult. You can help the situation by making a stop with a diameter the same as the low tolerance on the chucking diameter of the part. With a chucking diameter of .500" that has a tolerance of -.005", the work stop bore should be .495" to .4945". This will help stop the collet from collapsing in the back.
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Category: HQC Hardinge Quick-Change Collet System
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What happens when the seal holding the pads together breaks?
You can quickly replace the seal and the plug that holds it in. With other brands of quick-change systems, the entire head has to be sent back to be re-vulcanized. This requires an inventory of extra collets to make certain your production is not interrupted. We are told that most shops that use the vulcanized-style system purchase a minimum of 10 collet heads for their 8 spindle automatics to reduce the downtime. This additional expense is not required with the Hardinge HQC System. The only item required is an extra set of seals and about five minutes of time. If your shop requires collet heads for ten different stock sizes, the cost for extra vulcanized collets will be in the thousands of dollars. The cost for an extra set of Hardinge HQC seals is around ten dollars.
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Category: HQC Hardinge Quick-Change Collet System
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How often do I need to remove the Quick-Change System and clean the spindle?
Use the same schedule recommended by your machine tool builder. The seals on the HQC Quick-Change System create a better seal than master collets, helping to keep chips and sludge away from the back of the collet. You must still clean your spindle on a regular basis or you will eventually have problems.
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Category: HQC Hardinge Quick-Change Collet System
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Should I buy a manual or hydraulic wrench?
A hydraulic wrench and power unit is required on a multi-spindle automatic. The work area is too confined and the reach too long for you to comfortable and quickly change the collets.
For CNC lathes, a 3/8" ratchet wrench works great. If you want to increase your speed of collet changing, a hydraulic wrench will do it.
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Category: HQC Hardinge Quick-Change Collet System
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Can I get the collet to open up a little more to handle bar stock diameter variation?
You can adjust the collet to open approximately .008" more. During setup procedure, the collet body or the draw tube adapter was set with a .030" clearance between the front of the body, or adapter, to the back face of the spindle mount. This amount can be decreased to .005", which will allow the collet to open approximately .008" more. Make certain there is at least .005" clearance, otherwise the face of the body/adapter will hit the back of the spindle mount and cause damage to the assembly and/or the machine tool.
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Category: HQC Hardinge Quick-Change Collet System
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Do I need to balance the shell mills, taps, slitters, stub arbors, Jacobs chucks, Morse taper and boring head toolholders?
No, unless they are used at high rpm. Generally, these holders are run at low rpm and balance isn't a factor.
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Category: Mill Tooling
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Can I use the standard unbalanced ER Collet Holders and End Mill Holders on my 10,000 rpm spindle?
No, unless you are always running less than 6,000 rpm. The Basic Balance holder should be used on 10,000 rpm spindles and should also be used when machining above 6,000 rpm on 7,000 and 8,000 rpm spindles.
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Category: Mill Tooling
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Some of my drills and taps are spinning in the ER tool holders. Is there a way to get a better grip?
Yes. Use the ball bearing nosepiece. It allows almost twice the torque of the standard nosepiece. The new ER Collet with a square will help with tap slippage, when combined with ball bearing nosepiece, for an even tighter grip.
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Category: Mill Tooling
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Why shouldn't I use end mills with Weldon flats in collet-style holders?
Non-symmetrical tools should not be used in a collet-style holder. The Weldon flat makes the end mill unbalanced (non-symmetrical) resulting in poor finishes and possible spindle damage.
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Category: Mill Tooling
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I can't seem to get the drill parallel to the centerline of the spindle. Why?
A common cause for this problem is locking the second set screw on the bushing. The holes for small diameter drills do not extend the full length of the bushing. The back end of the bushing usually has a large internal chamfer or a counterbore. This cleared area is under the second lock screw. When you tighten this screw, the bushing may distort, shifting the drill's position. There may be line contact on which the drill will pivot. The solution is to use the front locking screw only.
A second cause is that the bushing is too short. The first set screw is locking on the back of the bushing, causing it to collapse instead of gripping the shank of the tool.
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Category: Split Drill Bushings
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Can I use the collet angle on my step chuck and not use the closer?
No. Centrifugal force will open the leaves of the step chuck when not contained by a step chuck closer. The part may come out and the leaves may break, causing damage to the machine tool and/or severe personal injury.
The only safe place to use the head angle to close a step chuck is when using stationary index fixtures and collet blocks. Even in these instances, you will hold the part more securely with a closer.
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Category: Step Chucks
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Can I use cast iron step chucks from old manual machines on A2-5 or A2-6 machines?
The step chucks for use in A2-5 and A2-6 spindles are longer than the step chucks used on manual and automatic Hardinge lathes. If they are used on other manufacturer's equipment, they may break, or open up due to the high centrifugal forces generated by a CNC lathe's high spindle speeds and quick spindle reversals. Machine tool damage and/or severe personal injury may result.
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Category: Step Chucks
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Why purchase Master Collets and Feed Fingers rather than Solid Collets?
While the initial investment will be slightly more, the advantage of achieving more versatility at a lower net cost assures the user of a profitable return. Master collets and feed fingers are capable of holding and feeding bar stock in a variety of sizes and shapes by using interchangeable pads. Thus, the same workholding tool can be used for more than one job to reduce tooling cost, provide greater flexibility in operation, and save on storage space.
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Category: Style S Master Collets
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Can I use my Style S Master Collets on my CNC Lathe?
If you're doing bar work, they work very well. The Style S Master Collet system was developed for use on multi-spindle automatic bar machines where collet runout is of very little concern. Secondary work on CNC machines usually requires very good collet concentricity, usually better than .001" TIR. Style S TIR could be as high as .004" to .008", therefore making them unacceptable for secondary work.
In an emergency, there are emergency pads which will work. Once you remove them, however, their TIR will be unacceptable if you try to run the same job again.
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Category: Style S Master Collets
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When ordering a Style S Master Collet, why do I need to know what machine it will be used on?
The master is a shell for the pads. Each shell fits a specific machine. The master is a shell of the solid collet, which are all different, depending on the machine involved. For example, a 2" Acme Gridley collet would not fit a 2" Greenlee. The pads are the same, but the shell is different.
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Category: Style S Master Collets
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How can I prevent chips getting between the draw bar face and the face of the collet?
The collet closer must be in the full forward position (OPEN) when mounting the Sure-Grip Expanding Collet. Do the following:
. Open the collet closer and check the clearance between the back face of the draw plug and the face of the collet--there should be none. If there is, loosen the closer and rotate it until there is no clearance. You can go a little further than eliminating the clearance, actually causing the collet to open a very small amount. Make certain that your part will go on before securing the closer at this position. Secure the closer. Put your workpiece on the collet and close it. You should now be back in business.
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Category: Sure-Grip Expanding Collets
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How do I decide whether to purchase collet-style or spindle-mounted systems?
Collet-Style should be your first consideration. The set up time is much less with the collet style. They can be used on the lathe as well as grinders, indexing fixtures and other workholding devices. The 16C and 3J handle the full range of collets. The 5C will go up to 3".
Consider the spindle mounted when doing heavy stock removal. We suggest that you start out with the collet style and only move to the spindle mounted style when the collet style does not perform adequately for roughing operations.
With the spindle mount style, the arbor mounts directly to the spindle for maximum rigidity. The force from the collet closer is directed only to the collet. With the collet style system, some of the closing force is also used to hold the arbor firmly seated in the collet seat. Heavy cutting pressures can create pressures that could affect the collet style system but not the spindle mounted system.
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Category: Sure-Grip Expanding Collets
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What is the difference between Hardinge "S, "M" and "L" Expanding Collets and the Sure-Grip Expanding Collet System?
The Sure-Grip system pulls the workpiece back firmly against the work stop, creating an extremely rigid part. Because of this, longer parts can be machined without chatter which increases tool life. This same feature results in the ability to take much heavier cuts.
The Sure-Grip Arbors are more massive and do not flex due to tool pressure. The Precision Style collet system is the weak link. It can flex under a heavy cut.
The Sure-Grip Collet opens parallel to the centerline of the spindle, not just on the end. This parallel opening insures bearing the full length of the workpiece's bore, resulting in more gripping force and better TIR.
No centering adjustments are required on the Sure-Grip system. Every time a different collet is used on the Precision Series, the collet has to be accurately centered. This can take from 10 minutes to an hour.
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Category: Sure-Grip Expanding Collets
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Why do I have to use a stop plate with my Sure-Grip Expanding Collet?
The expanding collet is pulled back with a draw plug to open it. If the chucking ID of the parts vary, the collet will pull back or stick out farther than the previous piece. The Stop Plate eliminates the movement of the part and also stabilizes it for heavy stock removal.
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Category: Sure-Grip Expanding Collets
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Can I machine a workpiece without using a work stop?
The collet draws back as it grips the bore of the workpiece. Any variation in the gripping diameter will cause the part to pull back farther or less than the setup piece. If you are only machining the OD of the part, then a work stop is not necessary.
Unfortunately, 99% of the time this is not the case. Usually you will be machining a face or shoulder which has a length dimension that has to be held to a locating surface. This requires a work stop.
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Category: Sure-Grip Expanding Collets
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Do I have to buy a different collet for each different bore size?
The collets will handle a variation in size of -.001" to +.015" (-.025mm to +.387mm). If you have a 1-3/4" (6.35mm) collet, it can grip workpieces that have bores from 1.749" to 1.765" (6.1mm to 6.969mm) in diameter.
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Category: Sure-Grip Expanding Collets
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Will I damage the collet if I close it without a part on it?
The Sure-Grip system is designed to eliminate this problem. The draw bar will contact the face of the arbor before the collet can be overexpanded.
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Category: Sure-Grip Expanding Collets
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Are there Emergency Expanding Collets available?
Because the collets come in 1/64" (.3968mm) sizes and each collet can handle a variation of -.001" to +.015" (-.025mm to +.381mm) there is no need for emergency collets.
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Category: Sure-Grip Expanding Collets
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Can I grip internally on a hex-shaped part?
Yes, hex and square collets are available.
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Category: Sure-Grip Expanding Collets
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Can I damage my Sure-Grip System if I use too much draw bar force?
The maximum draw bar forces are as follows:
Spindle Mounted Style:
Series #100 thru #250, max. lbs. is 2,000.
Series #300, max. lbs. is 4,000.
Series #400, max. lbs. is 5,000.
Series #500 and #600, max lbs. is 9,000.
Collet Style:
Series #100 thru #250, max. lbs. is 2,000.
Series #300, max. lbs. is 4,000.
Series #400 and #500 for 5C spindles, max. lbs. is 4,000.
Series #400 for all others, max. lbs. is 7,000.
Series #500 and #600, max lbs. is 7,000.
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Category: Sure-Grip Expanding Collets
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I want to take 1/8" off a part while holding on a small bore. Can I use the Model #100?
The #100 collet is for light machining operations such as taking a few thousandths off the face or OD of a workpiece. We recommend that you use the Model "S" Precision Expanding Collet for heavier stock removal on parts with bores less than 1/2" (12.7mm) in size.
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Category: Sure-Grip Expanding Collets
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