Does China have their own standard for Acme threads?
Does China have their own standard for Acme threads?
(OP)
I am retrofitting some parts. All is fine until I got to the threads. I ran the od and pitch on a acme ans stub acme thread calculator, but the numbers dont jive. Does anyone if China uses a standard different from the standard U.S. acme or stub acme threads? It is measuring out at 64.8mm od X 4.0 pitch (2.55" x .157").
thanks
thanks





RE: Does China have their own standard for Acme threads?
I see no indication that this will change, ever.
Mike Halloran
Pembroke Pines, FL, USA
RE: Does China have their own standard for Acme threads?
In general, knock off copies are said to be interchangeable and they never are. Reverse engineering is a black art, they are not particularly good at it in comparison to India for example.
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada
RE: Does China have their own standard for Acme threads?
Not sure it would make much difference but I've never really played with the trapezoidal metrics so don't know.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Does China have their own standard for Acme threads?
I have searched to see if their is a metric type of thread similiar to an acme or stub, but cant find anything. After measuring the part, it almost looks like a stub acme that they modified to take the minor down .040". Its almost like they took an average of acme and stub acme.
For people that use metric only. Is there a metric type of acme or do you just use a 2G acme, but use metric dimensions?
Thanks again guys,
RE: Does China have their own standard for Acme threads?
ht
It appears to show a 65 X 4 thread which is close to what you have when you take into account likely tolerance.
Or you may be able to google something better that actually gives you the tolerances etc.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Does China have their own standard for Acme threads?
Allowance,0.095
Major Diameter Max,65.000
Major Diameter Min,64.700
Pitch Diameter Max,62.905
Pitch Diameter Min,62.605
Minor Diameter Max,60.500
Minor Diameter Min (Ref),60.030
Root Radius Max,0.250
Root Radius Min,--
Flat At Root,1.330
Thread Height (Basic),2.250
Tr65 x 4-7H
Minor Diameter Min,61.000
Minor Diameter Max,61.375
Pitch Diameter Min,63.000
Pitch Diameter Max,63.400
Major Diameter Min,65.500
Flat At Root,1.330
Thread Height (Basic),2.250
Pitch,4.000
Lead,4.000
Starts,1
Lead Angle,1.160
Included Angle,30.0000
Software For Metalworking
http://closetolerancesoftware.com
RE: Does China have their own standard for Acme threads?
So aroundhere ringing any bells yet?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Does China have their own standard for Acme threads?
They (chinese) are getting better in the quality. They still match drill alot of parts at assy and sometimes no 2 parts are the same.
thanks
RE: Does China have their own standard for Acme threads?
Basic profile is like regular metric trapezoidal thread DIN 103 except minor dia..
Din 103 Basic Profile Thread Depth = 0.5 x P.
Din 380 Basic Profile Thread Depth = 0.25 x P
mrainay is correct on DIN 103