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Gallery, Projects and General => How do I?? => Topic started by: speedibee on November 04, 2018, 06:36:38 PM

Title: trapeziodal "Acme" thread
Post by: speedibee on November 04, 2018, 06:36:38 PM

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 ?

Title: Re: trapeziodal "Acme" thread
Post by: Lew_Merrick_PE on November 04, 2018, 11:10:47 PM

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.

Title: Re: trapeziodal "Acme" thread
Post by: efrench on November 05, 2018, 03:10:56 AM

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

Title: Re: trapeziodal "Acme" thread
Post by: AdeV on November 05, 2018, 03:14:08 AM

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....

Title: Re: trapeziodal "Acme" thread
Post by: speedibee on November 05, 2018, 08:01:21 AM

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 ?