Material or parts that cannot be used for their intended purpose because a dimension, feature or material property is out of specification and cannot be reworked. Scrap is tracked by job and cause, and scrap rate is one of the main measures of a shop's process control. To scrap a part is either to reject it officially or to ruin it, as in he scrapped the last one by going undersize.
Bore's oversize by four tenths and there's no rework on that print, so it's scrap, tag it and log it.
Taking off more is always possible and putting it back is not, which is why careful machinists sneak up on every critical size.
Also heard as
- reject
- scrap part
Related terms
Tolerance
The total amount a dimension is allowed to vary from nominal and still be a good part.
First article
The first good part off a new setup or program, fully inspected before the rest of the run is made.
Hooped
Canadian slang for broken, ruined or beyond saving, whether a part, a machine or a plan.
Sneak up on it
Approach a final dimension with smaller and smaller cuts, measuring between each, so you never go undersize.