Wheel bolt length

[daught]

I have a set of aftermarket wheels that I am pretty sure the conic bolts they have are shorter than stock length. Anyone know the aftermarket conical bolt specs, or even better can someone measure how far an original bolt stick out from the back of an original rim?

[Skyler@Achtuning]

You will want 19mm of thread protruding from the back of the wheel with the bolt seated as long as you are not using wheel spacers.

[A4 Quattro]

Stock ball seat bolts are 14x1.5x27mm. When I measure my ball seat bolts and cone seat bolts side by side, the cone seat bolt looks shorter, but the threads are exactly the same. [I was pretty sure I had a picture to put here, but it appears I may not.] Provided the head is still 17mm, and the aforementioned specs match your bolts, they will fit right. Always make 100% sure you are using the right bolts for your wheels. Not all aftermarket wheels are cone seat.

[daught]

Damn. The conical wheel bolts that my car came with protuded 17MM.

The ronals I got for winter came with ball seat that protuded 21MM.

A wheel shop told me not to worry if the bolts are a bit shorter. Is that true? Will the short bolts be an issue?

[g huns]

Damn. The conical wheel bolts that my car came with protuded 17MM.

The ronals I got for winter came with ball seat that protuded 21MM.

A wheel shop told me not to worry if the bolts are a bit shorter. Is that true? Will the short bolts be an issue?

I don't know about metric threads, but with common inch threads, in steel 1.0 times the diameter of the screw is considered "full" engagement. For aluminum it's 2.0 times the diameter. And in case anyone cares, it's 1.5 times the diameter in cast iron. That's as strong as bolt/threaded hole will ever be.

14mmX1.0=14mm. Any more thread than that is just showing off. Oops, gotta add for the rotor thickness that's sandwiched between the wheel and the spindle, guessing 5mm. That makes Skyler's 19mm right on the money.

Your 17mm bolts are only 2mm too short. You'd need an engineer to tell you exactly how much peril you would be putting yourself in, but I doubt it's enough to worry about.

[daught]

Nice thx.

One more thing. How much better are original audi wheels than aftermarkets? They seem to sell for twice as much, are they worth the money? I really like the B7 10 spoke, but I am not going to get them just for looks alone.