What's So Special About A Collet, Anyway?

A collet essentially a type of bushing, but is often used in machining in the form of collet chucks. 

Collet chucks are one of the simplest chuck designs, and can reduce downtime as well as being self-centering. Collet chucks are fantastic for making quick changes between workpieces, so long as the workpiece is cylindrical and of the appropriate size of the chuck. 

This has made them one of the most common chucks in machining, so few shops will not have a collet chuck or entire collection of them available. 

If you're a purchasing agent, in charge of sourcing equipment for a machine shop - and aren't a machinist yourself, and have barely any idea of what one does! - here's a quick run-down. 

What Is A Collet? 

A collet is essentially a cylindrical sleeve that forms a collar around the object that's being held, with a conical outer surface and a cylindrical inner surface. The conical end - typically at one end of the collet - provides uniform pressure on the object being sleeved. 

Collets are typically made of spring steel for use with most applications, and are given vertical kerf cuts. As the workpiece or whatever object is being sleeved with the collet is inserted, the collet will expand slightly, but so long as the collet is not stretched to the point of deformation, provides uniform spring pressure and holds the object in place. 

Collets are naturally centering, holding the object as it rotates, and holding with appreciable strength. 

While collets naturally have many applications - collets are usually employed in engines to hold the inlet and exhaust valve springs under constant pressure - they are most common in machining applications, both for milling and turning applications. 

Collet Chucks Are Almost Endlessly Useful...Until They Aren't Appropriate

Collet chucks are one of the most versatile types of chucks used in various workholding solutions, but like many tools have a specific range of applications. When they're appropriate to use, it's one of the best tools in existence. When they aren't, a different type of chuck must be selected instead. 

What does a collet chuck do? 

A collet chuck slides over the workpiece and - when secured - locks the workpiece in place. The workpiece is held in place, staying centered while being rotated and resisting vibrations very, very well. However, they aren't adjustable; collet chucks fit workpieces of defined sizes, so a machine shop will need a selection of them of various sizes. 

Additionally, collet chucks are also best-suited for use with cylindrical workpieces above all else. Eccentric and other shapes do not work well with collets as uniform pressure is not necessarily maintained across the entire surface of the workpiece. 

If you need to equip your shop with some new collet chucks, please don't hesitate to contact us for a free quote! Our support staff will be happy to describe our range of collet chucks and find the best workholding solution for your shop.