# Shear strength 316 Stainless v ?



## Tinbasher (6 Jul 2014)

What is more shear resistant than 316 Stainless steel.

Ihjave had a stainless 5mm set screw shear on my trike. I can't upgrade size wise so is mild steel more shear resistant?


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## CHJ (6 Jul 2014)

Tensile strength is roughly 85 ksi (85,000 PSI)

A lot more information Here

Would have thought that a standard Socket head cap screw would be better if the head can be accommodated.

How/why did it shear, over tightening or in use failure. 
Remember if you replace a failed in use item with something stronger then it can lead to the next item in the chain failing next time similar loads are applied.


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## Tinbasher (6 Jul 2014)

In use failure, it was locating one end of a solenoid actuator on a disabled gear selector adaptation (klictronic). After 10k miles and I suppose several thousand gear changes. Unfortunately the location means it can't be drilled out so I'm mulling over possible fixes.


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## DiscoStu (7 Jul 2014)

Gaffa tape or cable ties are my option!



I'll get my coat.


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## Tinbasher (7 Jul 2014)

DiscoStu":2p1m3wxq said:


> Gaffa tape or cable ties are my option!
> 
> 
> I'll get my coat.



They were as usual my first option


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## Spindle (8 Jul 2014)

Hi

Mild steel will be worse than stainless however a 12.9 grade cap screw will be an improvement as will using a screw, (with an unthreaded portion of shank), rather than a set screw, (where all of the shank is threaded), if this is possible.

Regards Mick


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## Tinbasher (9 Jul 2014)

Thanks Mick that's helpful.


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## Hitch (15 Jul 2014)

As above, a 12.9 cap head would be best i'd expect...perhaps a socket shoulder screw.... job to say without seeing it.
Both are commonly used in critical applications.


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## Bradshaw Joinery (16 Jul 2014)

some of my Racing car friends have bolts made in titanium to replace prone to failure items. 

I think they sometimes use this place..

http://www.pro-bolt.com/titanium/titani ... l?cat=1028


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## Spindle (16 Jul 2014)

Bradshaw Joinery":3lnp5p5o said:


> some of my Racing car friends have bolts made in titanium to replace prone to failure items



Hi

I think you'll find the reason to replace steel fastenings with titanium is weight reduction, (about 50%) - titanium has, however, a lower shear strength than high tensile steel, therefore in the OP's case I wouldn't recommend using Ti.

Regards Mick


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## Tinbasher (25 Jul 2014)

Finally sorted after another failure.












To explain, the plate clamps over the tube so that the brass piece sits where the original sheared stud is. The brass price is upgraded to 6mm and the free length of the 5mm screw is kept to a minimum.


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