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Help - whats the tensile stress area of an M42 bolt ?
mcerd1 - 15/5/10 at 08:37 AM

all the books / lists I can find stop at M30 or M36

does anyone know the actual area ?

cheers
-Robert

speedyxjs - 15/5/10 at 08:46 AM

M42!!! Thats a big bolt!

[Edited on 15-5-10 by speedyxjs]

oliwb - 15/5/10 at 08:49 AM

Think I am correct in saying it just the area of the diameter of the minor diameter (ie. root diameter). IIRC it would be something like:

pi x (37mm/2)squared

Depends on what type of M42 thread it is and the tolerances etc. What's it for anyhow?

02GF74 - 15/5/10 at 09:06 AM

1007

see page 299

http://books.google.co.uk/books?id=OIlAtjcZjWEC&pg=PA299&lpg=PA299&dq=m42+bolt+data&source=bl&ots=rC9JRugOxU&sig=FUFMcvGy9ar7t Ko8IqhmTfnvQl4&hl=en&ei=kGPuS7j9M5r60wS9tYnbBw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCIQ6AEwAjgK#v=onepage&q&am p;f=false

[Edited on 15/5/10 by 02GF74]

02GF74 - 15/5/10 at 09:10 AM

quote:
Originally posted by oliwb
Think I am correct in saying it just the area of the diameter of the minor diameter (ie. root diameter). IIRC it would be something like:

pi x (37mm/2)squared



not far off - the data book states a bit bigger. maybe that takes into account a sliver of the thread?

dunno but google has come up trumps again.

mcerd1 - 15/5/10 at 10:39 AM

quote:
Originally posted by oliwb
Think I am correct in saying it just the area of the diameter of the minor diameter (ie. root diameter). IIRC it would be something like:

pi x (37mm/2)squared

Depends on what type of M42 thread it is and the tolerances etc. What's it for anyhow?

thats what I've done for now - and its what the standards tell you to if you haven't got the right info - but my customer will want it more accurate than than

M42*4.5 (its a course thread) -> 34mm dia. -> 907mm^2

but the books I've got (the proper structural data books) have even bigger values than in that data book....


just found this on RoyMech: linky
so I guess I'll need to get the calculator out again

[Edited on 15/5/2010 by mcerd1]

mcerd1 - 15/5/10 at 10:51 AM

quote:
Originally posted by speedyxjs
M42!!! Thats a big bolt!

Its just the big end of the standard anchor bolts - we use M30 and M36 all the time...

rachaeljf - 15/5/10 at 10:56 AM

The 1007 mm2 mentioned above is the root area i.e. "Ab".

The tensile stress area of an ISO M42, i.e. "At" is 1120 mm2.
This is the value used in BS 5950 for design of bolted connections.

Cheers R

mcerd1 - 15/5/10 at 01:07 PM

quote:
Originally posted by rachaeljf
The tensile stress area of an ISO M42, i.e. "At" is 1120 mm2.
This is the value used in BS 5950 for design of bolted connections.


cheers - thats exactly what I was looking for
can I ask were you got that from ?

-Robert

rachaeljf - 15/5/10 at 09:37 PM

Try BS 3692

Cheers R

mcerd1 - 15/5/10 at 09:52 PM

quote:
Originally posted by rachaeljf
Try BS 3692

Cheers R


will do - must have looked in nearly every other bolt standard going...

cheers