USE/CARE OF HANDTOOLS & MEASURING TOOLS - OD1621 - LESSON 2/TASK 1
locked to act as a common screwdriver.
It has a knurled sleeve with a
spiral chuck and a control locking device which has three positions; right
and left ratchet, and rigid.
Some spiral ratchets have a spring in the
handle which automatically returns the handle for the next stroke. Another
with your fingers. The spiral type has separate blades that are inserted in
RATCHET SCREWDRIVERS AND SCREWDRIVER BITS.
(8) Screwdriver Bits. A screwdriver bit (figure 10) is a screwdriver
blade with a square, hexagonal (six-sided), or notched shank so that it will
fit in the chuck of a breast drill or ratchet bit brace, or on a square
drive tool, such as a socket wrench handle. Other screwdriver bits are made
with a spiral ratchet screwdriver shank for use with spiral ratchets.
(9) Jeweler's Screwdrivers. Jeweler's screwdrivers (figure 11 on the
following page) are made for driving and removing small size screws. The
tips range from 0.025 inch to 0.1406 inch wide. They usually have knurled
handles, a swivel end finger rest plate, and some have removable blades.