Machinists of the community: what was your most expensive scrap and what did you learn?

A batch of 40 brass fittings threaded to the wrong pitch because the drawing was updated and the old PDF stayed on the shop floor. Cheap material, expensive lesson: drawing revision control on every traveller now.

40 adet 316 flanş — ısıl işlem sonrası toleranslar kaydı çünkü nihai delik işlemesini ısıl işlemden önce yapmıştık. Artık kritik çapları her zaman son operasyonda bırakıyoruz.

Impeller in Inconel, 22 hours, tool broke on the last blade and the retract crashed into the next one. Now we use tool breakage detection and a mandatory retract-to-safe-Z macro after every roughing cycle.