On 07/05/2019 22:22, Harry Bloomfield wrote:
After serious thinking newshound wrote :
Interesting. I guess it is just meant to be on-off.

There has to be some initial slippage and wear, when it engages with the
engine running at full speed, so not quite on off.

Provided the load is high enough it probably never really slips. I
wonder if it is hardened steel, or just mild steel? Ordinary grey cast
iron would probably work OK as the graphite might help to prevent the
metal picking up or scoring.

The metal plates seem to be just pressed mild steel and both are quite
scored. I have had a long term issue with my grass being quite tough and
moist, jamming up the cutter deck - probably causing a lot of clutch
slippage.

I earlier ran a full test of my 'gasket material' modified clutch and it
seems to be holding up.

It might well be good. Quite simple heavy woven cotton used to be used
for clutches and brakes on things like cranes.