Rmd Steering Wheels

[Grim]

Having heard of several failures of RMD steering wheels, Al Milton sent me his unused steering wheel to examine. I've had the metal analysed by a handheld XRF machine, which has identified it as 6082 grade aluminium.

 

Typically this grade of material can be supplied annealed, for ease of processing, or in the heat treated (temper) condition. The hardness of a heat treated 6082 aluminium would be approx 75 - 100 HV. I tested a sample from the wheel, which measured 39HV, indicating it was annealed material.

 

This is pretty soft stuff, and in my opinion, not suited to the application.

 

As a comparison, a mild steel or a stainless steel would be about 150HV. A heat treated steel, such as a grade 8.8 bolt would be approx 300HV.

 

 

Andy

[fry61]

Thanks Andy;just the sort of factual report we need;your efforts are welcomed (was gonna say appreciated if that's correct spelling)

[speedtripledan]

glad mines long gone

[Guest mower man]

Great stuff ,as said thats the type of info needed to go back to suppliers/makers to get the s--t- off the market mower man

[Shaft]

39 Vickers?? That's almost Balsa Wood Andy!

[richardm6994]

out of pure interest and not knowing a great deal about this, what was the load and loading time used in the test?

 

from a long time ago, I seem to remember hv is worked out by how far you can press a diamond into the material using a set force over a set time?...or am I talking bo11ocks again

[Grim]

loading time of a vickers test is generally 15 seconds. The load was 5kg. I chose the highest load i could, whilst making the impression a measurable size.

 

Yep, that's pretty much the gist of it!

[Al Milton]

Thanks for the analysis Andy, guess the adage 'fit for purpose' springs to mind.

Glad my wheel was fit for something!!

 

Lets hope no one gets hurt by these dodgy wheels.

If you have one, heed Andy's report.

 

There may have been a suspect batch and hopefully this is not representative of these wheels

[Guest Peter Kelly]

What on earth is this thread about?

I think I have had too much Pop.

[Al Milton]

Just do a search.

You'll find posts about some of these failing (as in breaking) during normal use

[speedtripledan]

What on earth is this thread about?

I think I have had too much Pop.

I.e mine snapping when hard on the brakes approching a tight bend