Tensile and Shear Strength for #10 1.25ö PHSMS fasteners into aluminum

[SStein]

I am looking to find the tensile and shear strength properties of 1 1/4" #10 screws into 6063-T5 aluminum. The application is for connection between mullions of a manufactured vestibule. If anyone has any information or knows where to find this information, it would be a great help. Thanks.

 

[CoryPad]

PHSMS means Pan Head Sheet Metal Screw, which tells you basic geometry, and # 10 means it has a root diameter of 0.141 inches (if it is a Type AB screw thread, which is an assumpion). Typically, these screws are case hardened to a small depth so that the threads don't deform during tapping. However, the core of the screw material is unchanged, so it has low mechanical properties (~ 400 MPa ultimate tensile strength). The joint mechanical properties will vary with the hole size of the Al part. Rather than make several assumptions and calculations, you should contact the manufacturer of the vestibule and obtain their information. If they have none, then you should perform your own testing or find a new supplier.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Screwman]

I agree with Cory.
The fact that someone is looking for mechanical properties on a sheet metal screw is enough to cause the caution flags to good up to full staff. This type of fastener is not intended for structural loading the performance is entirely dependent on the condition and size of the hole in the nut member.

 

[dinjin]

A mullion acts as a structural member, and it carries the dead load of the weight above the opening and the wind load acting on the window unit back to the building structure. What does your mullion do? The aluminum will
be the week member. How do you tighten these screws?
With a torque wrench? Are you simply trying to minimize
the number of screws?

 

[KENAT]

http://www.boltplanet.com/default.asp

may help with some of the calcs, or at least to verify your own calcs.

KENAT,

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

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

 

[CoryPad]

KENAT,

This is a spaced thread sheet metal screw. There are no calculations like those for standard metric or UN threads.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[SStein]

Thank you all for helping me out with this issue. I have taken into account all that was said and I have decided to contact the vestibule manufacturer and get their take on the situation. Thanks again.