Measuring large items accurately i.e. +-0.1mm

[alanambrose]

Well good points, well made, particularly about expansion. To be more specific:

I have some folded steel parts being made to a target size of 799.5mm and they need to fit within a 'slot' of 800mm. I want to get a feel of the accuracy and variation of the delivered parts to check there will be no problems. So I want to measure a representative set of parts and I want to measure them to a fraction of a mm. I getting the feeling that a custom measuring jig (also in steel) which a micrometer engages with is the way to go. Chicken and egg problem of course, how do I check the jig :) I guess I'll get it carefully laser cut which in theory gives me a 0.1mm or better start?

Alan

[John S]

I have some folded steel parts being made to a target size of 799.5mm and they need to fit within a 'slot' of 800mm.

Alan

Impressive tolerances for folded steel parts. I wish you success :whistling: