JacketA jacket is a wood or metal frame which is placed around a mold made in a snap flask during pouring to support the mold and prevent a run out between the cope and drag.
Jobbing FoundryA foundry that creates a wide variety of castings, in small quantities for a range of customers.
Jolt-Squeezer MachineA combination machine that employs a jolt action followed by a squeezing action to compact the sand around the pattern.