Shear Breaking Strength

[smartyteddy]

I need to find the shear breaking strength of a tek screw. I know the weight of the item fixed to this is 24kg pulling directly down.

 

[Screwman]

What size screw? What material is it tapped into. How is the load applied, radius?

 

[smartyteddy]

Tek screw size is 5.5mm x 32mm screwed into structural steel perlin. The load is pulling directly down from the fixing position along the length of the screw.

 

[Cockroach]

Assuming SAE J429 Grade 8 or equivalent material, 59,940 lbf. This computation based on 32 mm full length engagement of the screw.

The pin (screw) has a maximum shear area/unit length engagement of 0.366 in^2/in, 0.539 in^2/in on the box (nut). Expect the screw to strip prior to the nut letting go.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[unclesyd]

What is the thickness of the purlin as this will determine when the Tek will strip out?

 

[Screwman]

What spec steel is the purlin? HSLA will give different results than mild steel.