Technical Information

Extended Nose Collets and Bushings:

Extended nose collets and bushings are used when clearance or reach becomes an issue. Since everyone's needs are specific, there is NO STANDARD extension. We recommend that when ordering, you order the extension as short as possible to suit your needs. If you are having the extended portion of the collet or bushing tapered, you can either specify to what diameter you want it tapered to or go with the standard that we have established, which is .200 larger than the bore diameter you require, however, in either case, you must specify that you want the nose tapered.

When ordering extended nose collets or bushings, please refer to the diagrams on the separate extended nose page of our catalog. It is helpful to us in insuring accuracy if you supply the "A" and "B" dimensions when ordering.

Overgrip Collets:

Overgrip collets are used when the collet must be sprung open to clear a larger diameter and grip on a smaller diameter behind that larger diameter. EXAMPLE: the threads of a screw measure .262 and the shank of the screw between the threads and the head of the screw is .250. You are inserting the screw "thread end first" into the sub-spindle collet. The collet would have to open up enough to clear the .262 and grip on the .250. Since the shank of the screw is a given length, the .250 bore of the collet must have a specific length assigned to it. We call that the "LAND". Since the machine has limited stroke when opening and closing a collet, you may want to contact the machine manufacturer to see if your specific application would be possible….

When ordering, please supply the following information:

  • Bore diameter
  • Overgrip diameter
  • Land

Step Bore Collets:

Step bore collets are used when the collet must hold 2 or more different diameters of a given part. EXAMPLE: A part has a diameter of .250 for .150 in length, then steps down to .200. You are inserting the .200 diameter into the sub spindle first and you need to grip both the .200 and the .250 diameters. The collet would have both bores in it, the .250 at the face of the collet and into the collet for a length of .150. The .200 bore behind the .250 bore would run into the backbore of the collet.

Please be aware that step bore depths of .050 and shorter are EDM'd, (ram style), into the collet with an EDM finish. Bores depths greater than .050 or XP tolerance will be a ground finish. Please specify "GRIND ALL BORES" when ordering step bores with bore lengths of .050 or shorter.

When ordering, please supply the following information:

  • Step bore collet
  • Bore diameter
  • Depth of bore
  • Thru bore diameter

True Serrated Collets:

Collets with true serrations are used for extra gripping force. Along with the radial grooves that are normally found in our collets with bores .500 and larger, we wire slots along the bore length to provide a waffle attern.

When ordering, please specify "TRUE SERRATIONS"

Collet Bores (Smooth / Grooved):

Please note: Bore diameters from .013 to .499 are normally smooth. Bore diameters .500 and larger are normally grooved. IF YOU ARE ORDERING A PICKOFF COLLET, (sub-spindle collet), it is imperative that you specify smooth bore if that is what you need.

Inclined slotted collets and bushings

In addition to using inclined slotted collets and bushings for pinion stock and profile stock, it can also be used to diminish the scratching of material as it passes thru the collet and bushing.

When ordering, please specify: "INCLINED SLOTS"

Drawing back into the guide bushing

When drawing material back into the guide bushing, we suggest adding a radius to the bore at the face of the guide bushing. This will minimize the grabbing effect that a sharper corner of the bore may produce.

When ordering, please specify "WITH BORE RADIUS"

Emergency collets and bushings

We offer emergency collets. We call them HARD BODY SOFT HEAD collets. They work by placing the provided pins into the pre-slots of the collet and closing the collet, then boring the collet to size. We recommend adding a little dab of grease to the pins when inserting them into the slots.

We recommend MEEHANITE guide bushings be used for emergency purposes. When ordering either emergency collets or bushings, please specify a bore diameter SMALLER then the finish bore diameter you desire. Even if we do not have the specific drilled bore you need to order available at that time, we may have something smaller in stock that you could use.