Check the insert before blaming the casting

MachiningA356Dimensional4/5 confidence

What we learned

What worked

Replacing the boring insert. The bore came back in tolerance with no casting change at all.

What failed

Two hours spent measuring castings looking for a shrink pattern that was not there.

War story

Eleven parts failed the bore check and the first instinct was that the casting had moved. The insert had 900 parts on it. Now the run sheet logs insert life next to the dimension.

Machining conditions

Feeds and speeds
Boring: 340 m/min, 0.12mm/rev, flood coolant
Fixturing
Three point clamp on the arm pads, bore up

Tags

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machiningtool-weardimensionalA356

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Captured Jun 12, 2026