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Technical guide

Regrinding and maintenance

The signs that tooling needs regrinding, what regrinding does to the tool height and the setup, and how to store tooling so it is not damaged.

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When should press brake tooling be reground?

Regrind when the wear land on the punch tip or the die shoulders has become visible, when the bend angle starts to need more correction than before, or when marking appears at the contact points. Wear is gradual, so the trigger is usually a change in the parts rather than a sudden failure.

What are the signs that tooling needs regrinding?

The practical signs are a growing wear land, a bend angle that drifts, marks appearing on the part, and increased tonnage needed for the same job. Any of these means the working surface is no longer the shape it was made to.

Wear indicators and what they mean
IndicatorWhat it means
Visible wear land on the tipThe tip radius has grown, so the bend radius grows
Angle drifting over a runThe effective tool height has changed
Marks or galling on the partSurface damage at the contact points
Higher tonnage for the same jobA blunter tip needs more force
Inconsistent angle along the lengthUneven wear between segments

How much material can be removed by regrinding?

Each regrind removes material from the working face, which reduces the overall tool height. The height reduction has to be compensated, either by the tooling setup or by shimming, and there is a limit beyond which the tool must be replaced.

Because regrinding changes the tool height, the amount removed has to be recorded. Without that record the setup drifts and the bend depth changes.

How does regrinding affect the tooling setup?

Reducing the punch height changes the distance between the ram and the die, which changes the bend depth for a given programmed position. The correction is either a shim under the punch or a change in the program.

  • Shimming: restore the original height with a precision shim under the punch.
  • Program correction: adjust the depth in the controller instead.
  • Mixed heights: the biggest problem in practice, because segments reground at different times no longer match.
  • Record keeping: mark the amount removed on the tool or in a register.

How should press brake tooling be stored?

Store tooling so the working faces cannot touch each other or rest on a hard surface, in a dry place, with the tool supported on its body rather than its tip. Damage in storage is as common as wear in use.

Storage practice
PracticeWhy
Support on the body, never the tipThe tip carries a concentrated load and chips easily
Keep segments in setsMixed sets give uneven angle along the length
Light oil filmPrevents corrosion on ground and polished faces
Dry, level rackMoisture and bending both damage ground tooling
Label regrind historySetup corrections depend on it

Related technical pages

Tooling hardness and steel grades

Why harder tools wear more slowly and chip more easily.

Troubleshooting

Diagnosing the faults that regrinding is meant to fix.

Tooling setup guide

Seating and aligning a reground tool.

Press brake dies

When a worn die is better replaced than reground.

Forged mould body after long service, before regrinding
A forged body that has taken years of production: the wear land is what regrinding removes.

Next step

Send photographs of the wear land and we will advise whether the tool can be reground or should be replaced.

Request a quotation

Send an enquiry

Tell us the machine make and model, or describe the tooling you need. We reply to every enquiry within one business day, and quote from a drawing for special profiles.

Prefer email? Write to roger@sharktoolings.com — enquiries from this form go to the same address.