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Should I remove the flash from a flash (butt) weld?


Frequently Asked Questions

A decision as to whether flash removal is necessary may be based on cosmetic or joint strength considerations. The joint can be stronger in tension because of the increased section produced by the upset, but the stress concentrating effect of the flash profile may be detrimental to fatigue performance. A safety critical application would therefore require a fitness-for-purpose analysis.

Where flash removal is necessary, it is often most easily achieved before the weld has cooled. A variety of mechanical shearing, grinding and die trimming methods is feasible.

Care should be taken to ensure that the flash removal operation does not undercut the original cross-section of the parts being joined. In addition, check that the operation does not introduce cracks or tears in the surface of the weld.

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