What would be the force required to sheer a 4 mm socket screw (aka grub screw), tensile strength 14.9.

(I need to see your working out)



in the application below.

there is a rod that is 15 mm diameter (L2) that is iniside a fixed steel tube.

A 4 mm socket screw is fitted between them.

At the other end is a lever, L1, that is 150 mm long.

A twisting force is applied to L1 of 100 kgf, so I reckon force across the socket screw is:

100 x 150 / 7.5 = 2000 kgf

This is applied across the 4 mm socket screw - will the socket screw sheer or not?

(cross section of m4 socket screw is 8.4 mm2)


sheer force?

[Edited on 18/10/10 by 02GF74]

If the bolt in in pure shear and there is no clamping friction to also resist the shear then the shear strength is 0.6 of the tensile strength

Yeild strength of a 12.9 bolt is 1100MPa or 1100N/mm^2, you should be able to work it out from there

But if not, root diameter of an M4 is 3.141mm, so thats a CSA of 7.7mm^2 so a yeild strength of 8470N or a shear strength of 5082N (518Kg)

Assuming single shear, if its double shear, double the force

Or if i read the whole thing it would help....

The shear info still stands though. Work in Mpa if you can, its easier

[Edited on 18/10/10 by flak monkey]

errrm yeah .... Think so .....

can you also explain E=MC^2

quote:

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Originally posted by mad4x4
errrm yeah .... Think so .....

can you also explain E=MC^2

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Easy.....4 white knuckles what else

http://xkcd.com/179/

Sorry if i'm being thick but Wouldn't the Hexagon in the middle of the screw 'give out first' ?

good observation, you get a gold star - yes it would but it depends on there the hexagonal hollow is in relation to the sheer (or is it shear?) plane i.e. using a long socket screw with the hollow part sticking out.

[Edited on 19/10/10 by 02GF74]