What is the static COF for rubber on steel?

[Mech King]

Hello all,

im trying to find some data for the static COF for rubber on steel. I have been looking hard but can only find info for rubber on concrete and other non metals.

I am doing the initial sums for a combat robot I am designing, but want to get the figures sorted out before i spend any money.

Best Regards,

Mech King

 

[brewnog]

Can only find lubricated, sliding COF for those surfaces in my references. It's 0.05.

 

[Mech King]

Hi brewnog, thanks for the reply.

Ye i's on of those combinations of materials that you would expectt here to be lots of info for the COF, but suprisingly not.

I have assumed a COF of about 0.9 to 1 for a rubber go kart wheel on a steel surface. I cannot find any exact grade of steel for the combat surface in the fighting robot standard.

Its always been one of those "suck it and see" areas for me (please excuse metaphor).

Cheers

 

[Nick Bruno]

This website here says Rubber on steel static friction coeff = 0.7

http://hypertextbook.com/facts/2005/steel.shtml

maybe this will help too. You may just want to make up your own experiment.
http://www.gordonengland.co.uk/sef/steel-rubber-friction-t-460.html

 

[brewnog]

I'd believe 0.7 (0.9 sounds very optimistic).

 

[Mech King]

Cheers for the responses guys, 0.7 sounds like the winner, i iwll have a closer look at these links aswell,

Thanks

Mech King

 

[turbo]

In addition, there are lots of different grades of rubber and lots of different grades and finishes of steel, so the COF will probably have a pretty wide range.