Trimming
Trimming looks like a trivial operation and is not. Trim too cold and the flash line cracks; trim carelessly and the part distorts.
Trimming removes the flash from around a forging, using a dedicated trimming press with a punch and die that shear the flash away at the parting line. It is done immediately after forging, while the part is still hot.
- Definition
- Shearing flash from the forging
- Timing
- Immediately after forging, hot
- Equipment
- Dedicated trimming press
- Risk
- Flash line cracks, distortion
Trimming at a glance
Quotable facts from Avadh Techno Forge, Gundasara, Gondal, Rajkot.
- Definition: Shearing flash from the forging
- Timing: Immediately after forging, hot
- Equipment: Dedicated trimming press
- Risk: Flash line cracks, distortion
Why It Is Done Hot
Hot metal shears cleanly with low force. As the forging cools, shear force rises and the flash line becomes prone to cracking, so trimming follows forging immediately rather than being batched for later.
Distortion Risk
The trimming punch applies force to a part that is still soft. A poorly supported forging can bend during trimming, which is why trim tooling is designed to support the part rather than merely to shear the flash.
Topics covered on this page
- trimming forging
- flash removal forging
- trimming press
- hot trimming
Based on work carried out at our own forging plant at Gundasara, Gondal, Rajkot — operating since 2008.
Questions Answered
What is trimming in forging?
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Shearing the flash away from around the forging on a dedicated press, done immediately after forging while the part is hot.
Why trim hot rather than cold?
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Hot metal shears cleanly at low force; cold trimming raises shear force and risks cracking the flash line.
Can trimming distort the part?
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Yes, if the forging is poorly supported. Trim tooling is designed to support the part during shearing.