USE/CARE OF HANDTOOLS & MEASURING TOOLS - OD1621 - LESSON 2/TASK 1
a grindstone or abrasive wheel. Hold the head of the mattock and tap the
opposite end of the handle on a solid surface to loosen the head. Slide the
head from the top of the handle. Remove nicks from the blade by moving it
back and forth across a grindstone. Make sure the edge is square across the
head. Grind the double bevel on the mattock blade by adjusting the rest on
the grinder; hold the blade against the rest and move the blade down onto
the abrasive wheel; do one bevel at a time and grind to the original bevel.
Dip the head in cold water frequently to prevent burning or loss of temper.
After sharpening, slide the head over the bottom end of the handle and into
approximate position at the top of the handle.
Tap the head end of the
handle on a solid surface to tighten the head on the handle.
a. Purpose. Soldering is joining two pieces of metal by adhesion. The
soldering iron is the source of heat for melting solder and heating the
parts to be joined to the proper temperature.
b. Types of Soldering Irons. There are two general types of soldering
irons, electric heated and nonelectric heated. The essential parts of both
types are the tip and the handle. The tip is made of copper.
(1) Electric Soldering Iron. The electric soldering iron (figure 56
on the following page) transmits heat to the copper tip after the heat is
produced by electric current flowing through a self-contained coil of
resistance wire, called the heating element. Electric soldering irons are
rated according to the number of watts they consume when operated at the
voltage stamped on the iron. There are two types of tips on electric irons:
plug tips, which slip into the heater head and are held in place by a
setscrew, and screw tips which are threaded, and which screw into the heater
head. Some tips are offset and have a 90 degree angle for soldering joints
that are difficult to reach (not illustrated).