(5) A prick punch is made of hardened tool steel ground to a slender, long
tapered, cone-shaped point terminating in a sharp 30 conical tip. It is used to
mark or identify scribed or layout lines on a piece of work, usually soft metal
such as brass. These marks are made at short intervals so that the reference lines
will be easily located.
EXERCISE
7.
Which file should be used to file the gullet between saw teeth?
a.
Triangular
b.
Pillar
c.
Flat float
8.
The hacksaw blade recommended for general use is the blade with
a.
14 teeth per inch.
b.
24 teeth per inch.
c.
18 teeth per inch.
9.
When cutting light sheet metal, which tool will not cause any metal to be
removed?
a.
Hacksaw
b.
Snips
c.
Trimmers
10.
Which chisel is used for cutting keyways?
a.
Diamond point
b.
Machinist flat
c.
Cape
11.
Which punch is used to lay out lines on a piece of work?
a.
Prick
b.
Drift
c.
Center
SECTION III.
PRECISION MEASURING TOOLS
6.
MEASURING TOOLS.
a. General. Measuring tools are designed for measuring work accurately.
They include level indicating devices, noncalibrated measuring tools (calipers,
dividers) for transferring dimensions, calibrated measuring tools (rules, tapes,
micrometers) designed to measure distances in accordance with one of several
standards of measurements, gages which are machined to a predetermined shape and
size for measurement by comparison, and combination tools such as combination
square designed to perform two or more types of operations.
b. Rules. All rules (scales) are used to measure linear dimensions. They
are read by a comparison of the etched lines on the scale with an edge or surface.
Most scale dimensions are read with the naked eye, although a magnifying glass can
be used to read graduations on a scale smaller than 1/64 of an inch.
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