Wheel bolt specs and info

[gadget1960]

Hi all, so .... I have my set of amg IV with a 2'' polished lip replicas 8.5 x 18 with 5x112 and et35 and 66.5 centre bore to be fitted to my 2001 w210, my questions are these ... the bolts I have currently fitted have the domed bolt head seating (NOT the straight taper type) but as they are fitted to my w210 I assume they are M12 ??
As I trial fitted one of the bolts to the new amg replica wheel I noticed that as the bolt is dropped into the wheel bolt hole there is a good 3-4 mm play side to side! assuming the amg rep: wheel has a hole for the m14 bolt ... do I need to buy a set of m14 shank bolts with an m12 thread or are the m12 bolts ok to use?

 

[hotrodder]

Yeah, a 210 uses M12 x 1.5mm wheel bolts. I dunno if AMG IV exist for m12 fitments and replicas throw a curve ball into the mix anyway but it's the seating surface of the bolt head that needs to match the wheel not the shank dia which also sets the OD of the bolt thread [/pedantic] With radius/domed bolt seats the radius changes with bolt size i.e. your m12 x 1.5 bolts have a 12mm radius seat while m14 x 1.5 bolts have a 14mm radius seat
Assuming the new wheels are designed for M14 with a radius seat you need M12 x 1.5 bolts with a 14mm seat radius which should be available from places like alloywheelsdirect

 

[gadget1960]

Yeah, a 210 uses M12 x 1.5mm wheel bolts. I dunno if AMG IV exist for m12 fitments and replicas throw a curve ball into the mix anyway but it's the seating surface of the bolt head that needs to match the wheel not the shank dia which also sets the OD of the bolt thread [/pedantic] With radius/domed bolt seats the radius changes with bolt size i.e. your m12 x 1.5 bolts have a 12mm radius seat while m14 x 1.5 bolts have a 14mm radius seat
Assuming the new wheels are designed for M14 with a radius seat you need M12 x 1.5 bolts with a 14mm seat radius which should be available from places like alloywheelsdirect

Thanks for the info, just done some measuring and found that the radius bolts are indeed 12mm which seem to be a perfect fit / seating in the new wheel (no slop when seated). although the hole they pass through is 15mm which is quite large for an m12 bolt shank I would imagine? i have access to a lathe and was thinking of making up some bushes to press into the stud holes to reduce them to m12 shank dimensions so the bush would be 15mm OD 12mm ID and 8mm thick, also the original bolts are approx.: 10mm too long due to the thinner mounting face of the new wheel (8mm thick).
How many threads / turns are required in order to securely fit the wheel? i heard / read somewhere it must be between 6-7 full turns, is this correct?

 

[tjamesbo]

Full penetration of the hub at the front and not much more than full penetration at the rear so that it doesnt intrude on the Handbrake mechanism
This can be determined by measurement of the hole depth on the hubs and how much bolt protrudes when sitting in the wheel You could calculate how many turns required to acheive that based on the threads per inch of the M12 bolt