- A/F = across flats. Usually this refers to the size of a hex nut or a hex head on a bolt, as in '8mm A/F' or '9/16" A/F'.
- aka = also known as
- A/R = as required.
- CW = clockwise
- CCW =counterclockwise
- 'left' and 'right' always refer to an operator/user's left and right as he or she operates/uses the subject machine/contrivance/what-have-you.
- PCA = Printed Circuit Assembly
- 'screw' means machine screw.
- thou = thousandth of an inch
- 'threading screw' means a coarse-threaded thread-forming screw as is used in plastic or sheet metal or with a Tinnerman nut.
- w/ = with
- w/o = without
- YZD = yellow zinc dichromate, a yellow-coloured plating used on many fasteners.
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