Sherline's drill chucks are made in the USA by Jacobs. They are available in 5/32", 1/4" and 3/8" sizes. Runout is .003" or less.
If runout of less than this amount is required, collets should be used to hole the drill rather than a chuck.
The 5/32" chuck holds drills from 5/32" (4mm) down to #80 (.0135" or .343mm).
It is designated "0JT" which stands for "Zero Jacobs Taper", because it comes with a #0 Jacobs tapered hole in the back.
Into that we have pressed a special arbor that provides either a #1 Morse taper to fit into the Sherline headstock (P/N 1010) or a #0 Morse taper to fit the tailstock (See P/N 1015).
A chuck key plus a drawbolt and washer are included with P/N 1010 to secure the chuck in position.
These chucks are useful for holding very small drills and their shorter length provides an increase of about 1/2" in working space between centers compared to the 1/4" drill chuck.