I did some googling and came up with some dentist drills that do about 500,000 rpm and obviously the smaller / thinner something is, the faster it can be spun - a spindle etc.

Also there appears to be some missile guidance systems which spin pretty fast, but even taking all this into account, man must have made something which spins faster than all the others. What is it?

There must be a relationship between the strength of a material and the max speed that - say a disk of material x, weighing 5 grams / 3mm thick, can be spun before it breaks up. Anyone know what this is? And what material is most resistant to centripetal force?

( for uk dopers - i’m sure there is a Alistair Campbell joke in there…)
Sin

A drill that does 500,000 RPM? That seems hard to believe.

This page says the “fastest spinning object ever created” is a flywheel that spins at 65,000 RPM. But I thought some common-caliber bullets (.223?) spin up to 100,000 RPM?

I’ve used this air-driven centrifuge many times, and it has a top speed of 100 000 rpm. I love it, because it sounds like a miniature jet engine winding up. It also does wonders for really lipemic serum samples.

The formula for maximum stress in a solid spinning disk is:

S = (material density) x (rpm squared) x (radius of the disk squared)/(110.5 x g)

S = stress in psi (metric: S = Pa)
Material density in lb/cubic inch (metric: kg/cubic meter)
radius of disk in inches (metric: meters)
g = 386 (metric: g = 1)

A mild steel disk (AISI 1010) will break apart when S = 67,000 psi (462 MPa)

This formula is from Design of Machine Elements by Spotts.

You’ll soon find out the worst part isn’t when Tom lays the mod cane to your fleshy buttocks, but when he says he’s disappointed in you. You just die inside.

You’d assume a particle accelerator can spin a proton over a small circular track alot faster than 500,000 RPMs. I do not know if that constitutes man made though, at least not in the way that a mechanical device like a drill is manmade.

Thanks for the replys - i guess there must be a limit around the 500,000 rpm mark them, but with pretty small objects - and thanks for the equation Mr Truth.

I already spotted the Kxan link Crafter - the company its talking about has v little info on its web site. But Ta.
Sin