Bolt Withdrawal Values in Steel, Alumnium

[IsaacStructural]

I've got a large aluminum sculpture I've been asked to look at. It contains some connections with drilled and tapped holes into the material. The holes don't go through, so there is no nut or washer. So any tension on the bolt is being transferred through the threads of the hole. Could someone recommend reference material for determining the minimum thread length to fully develop a given bolt size?

If someone has the above resource but only for steel, I'd also be interested in seeing that.

Thanks.

Licensed Structural Engineer and Licensed Professional Engineer (Illinois)

 

[SnTMan]

Machinery's Handbook has it all.

Regards,

Mike

 

[kingnero]

I believe this is extensively documented in Machinery's Handbook.
roymech.co.uk also has (had?) it.

Maybe someone else can help you with a link to somewhere on the www, if not I will gladly scan the pages for you from my version of Machinery's Handbook.

 

[IsaacStructural]

Thanks! I'll see if I can dig up a copy. It actually doesn't look to be too expensive on Amazon, so I might just purchase a copy to have around the office.

Licensed Structural Engineer and Licensed Professional Engineer (Illinois)

 

[SnTMan]

If I could have only one book, it'd be M.H.

Regards,

Mike

 

[IsaacStructural]

The Machinery's Handbook just arrived. It has to be the fattest, stoutest book I've ever seen. Now hopefully I can find the information I'm looking for. A quick glance through suggests it has a lot of other fun stuff as well.

Licensed Structural Engineer and Licensed Professional Engineer (Illinois)

 

[Tmoose]

For charts of what in the last millenium UNBRAKO (1996) felt were reasonable tapped hole thread strength to consider for a quality socket head capscrew into brass, aluminum, cast iron and mild steel, look at page 66/68 here -

http://www.dalecompany.com/pdf/UNBRAKO.pdf

Note their comment on page 64/66 about using figgerin' and cypherin' to come up with tapped hole thread strength being "not entirely satisfactory". Thus what one of the premier fastener makers chose to present in the technical section of their "engineering guide" were tables created using empirical data from tests done with threaded test pieces and real bolts.