LATHE OPERATIONS - OD1645 - LESSON 1/TASK 1
collets are designed for heavy-duty turning and possess 2 to 4 times the
grip of conventional split steel type collets.
JACOBS RUBBER-FLEX COLLETS.
(9) Step Chuck. The step chuck is a variation of the collet chuck, but is
intended for accurate holding of workpieces larger than 1 inch in diameter.
The step chuck consists of the handwheel or hand lever collet attachment and
a step chuck machine collet in place of the regular spring machine collet.
The step chuck machine collet, which is split into three sections like the
spring machine collet, is threaded to the draw bar of the collet attachment.
As the step chuck machine collet is drawn into the collet sleeve, the three
sections of the collet are cammed against the workpiece by an inside taper
in the collet sleeve. The step chuck is supplied in 2, 3, 4, and 5 inch
sizes, the size indicating the maximum diameter of