17-7/304 cracking when curl?

[dchu129]

Would like everyone's input on this

17-7 material or 304 material is notch and curl. However during the curl, there will be crack on one side of the curl.

Tool guy is claiming it happens during notching (possible dull die and not enough clearance, because one side of the notch has more break out than the other).

Notch guy said they already sharpen the part and is blaming on the material, but the cert shows that material is good.

Would like everyone's input on this.

 

[EdStainless]

A little difficult to get without a picture, but my hunch is the notch.
Let me guess, these are not annealed materials that you are working with?
The edges of the notch need to be smooth, no lines. You may need to add a finishing operation to improve the surface.

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