USE/CARE OF HANDTOOLS & MEASURING TOOLS - OD1621 - LESSON 2/TASK 1
(1) Bench Grinder. A bench grinder (figure 62 on the following page)
is a device with an axle to mount an abrasive wheel and a handcrank that
will permit turning the wheel.
The grinder is geared so that the wheel
spins faster than the crank. This type of grinder is clamped onto a bench
and is equipped with a rest for alignment of the work when grinding.
(2) Mounted Grindstone. The mounted grindstone (figure 62) is foot-
The nonglaze grit stone is 2 inches wide and 22 inches in
A funnel-shaped container of water, which constantly wets the
stone during grinding, is suspended over the stone.
(3) Valve Grinder.
The hand valve grinder (figure 62) is a device
that is used to lap engine valves in their seats.
It consists of pinion
gearing enclosed in a heavy, machined, cast iron housing. An external crank
handle drives the gears, which rotates a shaft.
The end of the shaft is
designed to hold any one of three driving blades for use on slotted valves.
Nonslotted valves can be driven by a rubber suction cup, supplied with the
grinder, that fits the shaft. Two shafts are furnished; one short and one
c. Types of Sharpening Stones and Oilstones.
Sharpening stones and
oilstones are natural or artificial stones. Most sharpening stones have one
coarse and one fine face and are normally made of silicon carbide, aluminum
oxide, or natural stone. Natural oilstones have a very fine grain and are
excellent for putting razor-like edges on fine cutting tools. Some stones
are mounted and the working face of some of the sharpening stones is a
combination of coarse and fine grains. Stones are available in a variety of
shapes, as shown in figure 63 on the following page.