Reverse Tonnage
The snap-through shock load that recoils into the press when a cut breaks through.
What it means on the floor
When a heavy cut finally fractures, the stored energy releases suddenly and slams the press structure in the opposite direction. This reverse (snap-through) tonnage can damage the press and tooling even when forward tonnage is within rating.
Shear angles, staggered punch lengths, and slug-control features reduce snap-through severity.
Category: Press
Applying the term
Interpret Reverse Tonnage in the context of the drawing, governing standard, and customer requirement in front of you — the same word can carry different limits in design, quality, and production documents. Check whether a stated value is nominal, minimum, maximum, or reference-only, and whether it applies before forming, after forming, or after heat treatment.