tools n measures

Soft-faced hammer primary uses and limitations

Used for forming soft metals or striking surfaces that damage easily; should never be used on punches, bolts, or nails.

Screwdriver blade slot fit standard

The blade should fill at least $75\%$ of the screw slot width.

Phillips vs. Reed & Prince screwdriver geometry

Phillips features a blunt tip, whereas Reed & Prince features a pointed tip with a sharp cross; they are not interchangeable.

Duckbill pliers primary application

Used specifically for twisting safety wire.

Prick punch vs. Center punch

Prick punches produce light reference marks or transfer layout points; center punches create deeper indentations to start drill bits.

Drive punch vs. Pin (drift) punch shank design

Drive punches feature a tapered shank, whereas pin punches feature a straight shank.

Open-end wrench jaw angle

Jaws are set at an angle of $15^\circ$ relative to the handle.

Flare-nut wrench application

Designed for tightening or loosening B-nuts on fuel, hydraulic, and oxygen lines.

Click-type torque wrench signaling mechanism

Indicates attainment of the target torque setting via an audible click and brief tactile breakaway.

Aviation snips cutting margin

Cut approximately $\frac{1}{32}\,\text{inch}$ away from the layout line, then file to the final line.

$32\,\text{TPI}$ hacksaw blade application

Used specifically for cutting thin-walled tubing and sheet metal.

Safe edge on a file

A smooth edge without teeth that prevents cutting into adjacent surfaces.

Standard twist drill point angle

$118^\circ$ total angle ($59^\circ$ per side).

Hole preparation size prior to reaming

Holes must be drilled $0.003\,\text{inch}$ to $0.007\,\text{inch}$ undersize before reaming.

Standard aircraft countersink angle

$100^\circ$.

Taper tap vs. Bottoming tap

Taper tap initiates internal threading; bottoming tap threads to the bottom of blind holes.

Standard micrometer vs. Vernier micrometer resolution

Standard micrometer thimble division equals $0.001\,\text{inch}$; Vernier micrometer reads down to $0.0001\,\text{inch}$.

Dial indicator primary function

Measures shaft runout, alignment, bending, and material warpage.