j hook

A type of turnover shaped like a "J" for lifting or turning over dies or die sections.  Also see turnover.

j number

Number used to identify special accounts to cover the cost of new work or engineering changes.  Numbers can be found in a book in supervisor's office.  Also called project numbers or tool order numbers.

jig borer

A machine to locate and machine holes accurately. Also called a locator.

jog

See inching.

joggle

An offset surface consisting of two adjacent, continuous, or nearly continuous short radius bends of opposite curvature.

julian date

A three digit number designating the day of the year.  Examples: January second is 002, February twentieth is 051, November fifteenth is 319.  Used for stamping date on parts.