Thread Specification

[paramathma]

Hi,

Thread specified on a bolt drawing is "M2.5 x .45 4h".
Is the thread British standard ISO metric or ANSI/ASME metric thread?
Which standard do I need to refer to get minor, pitch dia of thread?
How do we know about the standard used?

Thanks

 

[CoryPad]

This thread is contained within ISO 261 ISO general purpose metric screw threads — General plan and ISO 724 ISO general-purpose metric screw threads - Basic dimensions.

 

[KENAT]

"M" is an indicator or metric thread.

Regardless of which countries spec you use they should all more or less conform to the ISO, kind of the point.

Ideally what spec it is to should be on the drawing, at least this is how it's meant to be done in the US.

KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at posting policies:

http://eng-tips.com/market.cfm?

What is Engineering anyway: faq1088-1484

 

[SWhit]

Look at BS 3643, I don't have a copy, it's referenced in a handbook I have.