trapeziodal "Acme" thread

[speedibee]

is all Acme thread Metric ?  I need some new nuts for my lead screw and cross  slide , I have only seen metric nuts and screws offered . how do i measure an Acme thread ?

[Lew_Merrick_PE]

Speedibee  --  Most ACME threads are inch-based.  In the metric system they are called Trapezoidal threads.  I have the complete (ANSI) datasets for them should you care to e-mail me (tangent@olympus.net) and I would be happy to e-mail you copies.

[efrench]

Metric trapezoidal threads are 30 degrees and Acme threads are 29 degrees.

[AdeV]

I'm sure the ISO did that deliberately, just to make absolutely sure no-one could re-use their ACME tooling to make metric trapezoidal threads....

[speedibee]

thanks for the info . re.: trapezoidal and acme , seems like  metric are much easier to find than  imperial , and i want a nut to modify my cross slide with  , another thing is  are the screws hardened or would it be possible to buy a metric screw and nut and machine ther ends myself ?