Is the EN9 grade steel good enough for 45mm wheel bolts?

EN9 will be fine as it is a high carbon, but be aware that some ebay sellers offer carbon steel and alloy steel so if it's not listed ask them a question.

So what I want is carbon steel then, right?

Yep

The grade should be stamped in the top of the wheel bolt. There's four grades, 4-6, 8-8, 10-9 and 12-9, and 10-9 is the most popular.

So you're bigger power now?

I will try to find out but he told me EN9 grade...

Yeap, bigger power now which I'd been craving more some time. Now need to shift the 16VT

Try and keep this one out the bushes mate

Joe ,you have listed the tensile/proof stress grading but not the material. Dean all steel is carbon steel but the quantity varies as do alloying elements its huge subject in itself. Secondly if you were to make some long bolts out of this EN9 (medium carbon) grade stock then I'd assume it would be threaded on a lathe, but production bolts have rolled thread thus if the material was strong enough to meet say the 12.9 grade (its not incidentally anywhere near it) it would probably fail due to the thread cutting process.

If you need long bolts, don't use bolts, buy suitable length studs M12 metric fine and nuts. Thread lock the studs into cleanly tapped hub threads and then you can take nuts on and off without them coming out. Please dont play around with fasterners they are critical in this application so use something ready made from a reputable supplier (eg demon tweeks).

rich

Rich, you you're recommending something like this - http://www.demon-tweeks.co.uk/motorsport/wheel-tyre-accessories/grayston-conversion-stud plus floating stud nuts? Why is this a better solution?

I've used Grayston Wobble bolts. They were totally unsuitable. They were machined from bar and not forged, and when I asked what material they were made from they refused to tell me.

Pushed for time Dean but this is the rough idea quicker than I can type it,

http://www.hardcore50.com/vbulletin/archive/index.php/t-35035.html

Thanks Rich, after scratching my head for a minute after posting the question I got to the same conclusion as in the link you posted. Now I have to find studs and nuts good for the job...

Are 9.9 grade studs and nuts going to be up for the job? I reckon with 15mm spacers I will need 60mm studs but still to measure this properly.