Collets offer a fast and accurate way to mount cylindrical parts or bar stock in a lathe. Each collet functions like a miniature precision 3-jaw chuck and fits into a tapered adapter mounted in the headstock. A drawbar passes through the headstock and threads into the rear of the collet, pulling it into the adapter. This action causes the collet jaws to close and securely grip the workpiece. Collets are known for their exceptional centering accuracy, but each collet size accommodates only a limited diameter range—typically ±.001" (0.02 mm).

WW Collets vs. Milling Collets

Unlike milling collets, WW collets feature a through-hole, allowing material to pass completely through both the collet and drawbar. The maximum diameter stock that can pass through is 3/16" (4.5 mm), although WW collets are available in sizes up to 5/16" (8.0 mm). Collets larger than the through-hole capacity are sometimes referred to as “pot chucks,” as they are only bored to a depth of approximately .260".

Collet Accuracy

Sherline WW collets are precision-made and have a maximum runout of .002" or less. When the WW collet adapter is properly trued as recommended in the instructions, runout is minimized, providing optimal accuracy. Pot chucks (collets larger than 3/16" or 4.5 mm) are not bored through and may exhibit increased runout if your part extends far beyond the front of the collet.

Logical Part Numbering

Sherline collets are organized by size for easy identification:

Inch Collets: Part numbers begin with 1160, followed by two digits representing the size in 64ths of an inch.
- Example: P/N 116013 is 13/64"; P/N 116016 is 1/4" (16/64").
Metric Collets: Part numbers begin with 1178, followed by two digits representing the size in 0.1 mm increments.
- Example: P/N 117813 is 1.3 mm.

Compatibility and Specifications

Sherline WW collets are manufactured in-house to standard WW specifications but are not hardened. The shank diameter is .312–.313", and the thread is .275-40. While some third-party WW collets may not fit properly, Sherline offers an optional .315" adapter and drawbar set (P/N 1163) to accommodate select 8 mm collets from other manufacturers.

Available Sizes

Sherline WW collets are offered in: