We provide an extensive line of collet blocks that can be used for milling, drilling, grinding, crimping, inspection, testing and assembly applications. Collet blocks can be used vertically or horizontally on mill tables, flat or angled fixture plates, tombstones or rotary trunnions. Sizes are available from the 1C micro medical manufacturing needs up to the 35J mid-range for applications in the automotive and aerospace industries. Purchase individual components to build our own pneumatic or hydraulic system, or let Hardinge configure a complete turnkey package for you.

Frequently Asked Questions

Which style collet block is best for me? Do I need pneumatic or hydraulic operation?

The part diameter or range of parts that you are working with will indicate the collet size required. The required gripping force will be determined by the part size and the machining process that you will perform. Higher gripping forces will be needed for heavy rotation, tapping, threading or off-center work. Hardinge will help you determine what size collet block you need, whether you need a high-force or low-force collet block, and if you need hydraulic or pneumatic operation. Clamp only what is required – operate at the pressure required for each individual machining application. Equivalent collet gripping forces at the maximum recommended draw bar force output are indicated above, along with the round collet maximum gripping diameter. Hex, square and custom-shape collets are available. Hardinge Sure-Grip Expanding Collets2 can be used in the 5C and 16C pull-back collet blocks for internal gripping. Step Chucks provide gripping for custom shapes or larger diameters up to 6″ (152.4mm) on select models.

What are the minimum and maximum part sizes that I can grip in a collet block?

What components do I need for a simple pneumatic configuration?

What is the purpose of using the standard manifold with a quick-disconnect handle?

Can I damage a collet by applying too much draw bar force?

Why would I need to choose a high-pressure collet block?

When do I need to use an accumulator?

What do I need to buy for a hydraulically-operated collet block fixture or tombstone?

If you don’t already have a hydraulic source at your machine, you would need to purchase a pump along with a 2-position, 4-way control valve. You can use one control valve to clamp and unclamp all parts simultaneously or configure multiple valves to control each block or row of blocks independently from others. The control valve would mount on the fixture along with the collet blocks and connect to the pump outside of your machine.

A quick-disconnect system is optional. A quick-disconnect handle with a standard manifold allows for a quick disconnect, but will not maintain the clamp position when removed from the fixture plate. To maintain the clamped position when removing the disconnect handle, you would use the manifold with a built-in check valve. This option is ideal for preloading pallets. A 3-position, 4-way control valve, and an accumulator are required when using the check valve option and the control valve would be mounted outside of the machine. The accumulator is available in a vertical or horizontal mount and will mount on the fixture with the collet blocks.

How many connector bushings do I need?

Will my first block have the same pressure as the last block in the row on my fixture plate?