Set Screw Holding Power

[mmazzuca]

I'm looking for information on calculating the holding power of small diameter(3-5mm) socket set screws.

There are a few design issues to factor in:
1)The length of the engaging thread is only about 1-2mm
2)The set screw is holding down a 5mm diameter rod
3)The set screw is so short the socket drive extends through the screw (making it hollow), which makes the wall thickness an issue.

I'm looking for ballpark figures so I only have to prototype one size.

 

[israelkk]

If the lenght of engaging thread is 1-2 mm then the socket diameter should be no more that 1-2mm respectively to insure enough threads for engagement. Usually it is not a good idea to use rely on set screw holding by friction unless the forces and very small like in the case of holding a potentiometer shaft.

You could drill a hole in the shaft and use longer set screw that will penetrate the hole in the shaft, But then you will have to be able to aim to the hole. If you make a conical hole you can create a tight holding and carry more loads.

 

[rickylee]

Check out Mark's handbook, holding power of setscrews found within.

Rick.