Comparing wheel studs for purchase: Differences?

[PDX.Duke]

I was able to, mercifully and without great effort, remove the welded-by-PO wheels studs from my front e21 hubs. I will be cleaning and prepping to install new screw-in studs. I've found a couple offerings online for what I need to fit my 13" Alpina rims (M12 1.5 x 57mm), but at wildly different prices. And since I'l, be buying between 8 and 16 of these, the difference adds up.

 

Having only fairly recently acquired my 2002, I am not very familiar with either the various vendors yet, or differences between wheel studs,  and hope to solicit advice/feedback from the hive. Here's what I've found:

 

1. Turner Motorsports (which I understand are owned by ECS Tuning?) have them in a "Black magnesium phosphorous corrosion resistant coating".  

PRICE: $11.99 ea.

https://www.ecstuning.com/b-turner-motorsport-parts/turner-motorsport-12x15-55mm-full-thread-wheel-stud-most-bmws-e30-e36-e46-e90-e92-etc/twh9950x55/

 

2. Ireland Engineering have them in some not specific silver finish.

PRICE $2.75 ea (theirs even included lugs, which I don't need)

https://www.iemotorsport.com/product/12mm-x-57mm-long-thread-in-wheel-stud/

 

3. And 2002AD.com seems to be selling the same thing as IE (and even uses the exact same text description), but for slightly cheaper at $2.19ea.

https://www.2002ad.com/storeworks/view_item.cfm?id=2589

 

So, my QUESTION: I'm assuming that the black magnesium coating matters? Can anyone fill me in on the fundamental difference?

 

Thanks!

[Mark92131]

Compare the shipping costs between IE and 2002AD and buy the cheaper one.   Install with red loctite.  To reduce rusting of the threads, a light coat of grease or anti-seize should work fine.  Buy something else with the $160 you saved.

 

IMHO,

 

Mark92131

[PDX.Duke]

41 minutes ago, Mark92131 said:

 To reduce rusting of the threads, a light coat of grease or anti-seize should work fine.  

 

Mark92131

 

Any concern that grease or anti-seize on threads could impair security of torqued lugs?

 

Thanks!

 

 

[Son of Marty]

For what it's worth I've had a 2002 in the Seattle area since 1973 and never had a rust problem with the hubs and hardware at all with nothing on the threads other than the afore mention red loctite to mount the studs to the hubs on a big brake conversion.

[AustrianVespaGuy]

24 minutes ago, PDX.Duke said:

Any concern that grease or anti-seize on threads could impair security of torqued lugs?

 

Thanks!

No. What we want out of (any) threaded joint is ultimately a desired CLAMPING force on the joint.  This both holds the joint together and in turn the preload on the threads then prevents it from loosening back up. In general any type of lubrication on threads does two things - due to the reduced friction you get more clamp for a given amount of tightening torque, but more importantly you get a CONSISTENT amount of clamp for a given torque by reducing 'sticktion' (the difference in peak force needed to overcome the static friction to get things moving vs. the lower dynamic friction once it is moving).

So for your wheel studs, is what this means is that with dry threads, lets say you torque the lug nuts to 100 Nm, and this results in something (just guessing) in the range of  70 ~130 MN of clamping force.  But now when you go to loosen it, and you find it takes 120 Nm to break it free again.

But on the other hand if you put some anti-sneeze on there first to lower the friction and tighten to the same 100Nm, you'll end up with a slightly-higher-on-average but more consistent clamping force, something like 100~120 MN, and you'll also find you only need maybe 105Nm of torque to break it back loose again.  Feel free to try it yourself with either an old-skool beam type or modern-skool digital torque wrench!  But ultimately the answer is no, if they're properly torqued down, lubed or not, the won't just come 'undone' unless/until a slightly greater loosening torque is applied.

[PDX.Duke]

6 hours ago, AustrianVespaGuy said:

No. What we want out of (any) threaded joint is ultimately a desired CLAMPING force on the joint.  This both holds the joint together and in turn the preload on the threads then prevents it from loosening back up. In general any type of lubrication on threads does two things - due to the reduced friction you get more clamp for a given amount of tightening torque, but more importantly you get a CONSISTENT amount of clamp for a given torque by reducing 'sticktion' (the difference in peak force needed to overcome the static friction to get things moving vs. the lower dynamic friction once it is moving).

So for your wheel studs, is what this means is that with dry threads, lets say you torque the lug nuts to 100 Nm, and this results in something (just guessing) in the range of  70 ~130 MN of clamping force.  But now when you go to loosen it, and you find it takes 120 Nm to break it free again.

But on the other hand if you put some anti-sneeze on there first to lower the friction and tighten to the same 100Nm, you'll end up with a slightly-higher-on-average but more consistent clamping force, something like 100~120 MN, and you'll also find you only need maybe 105Nm of torque to break it back loose again.  Feel free to try it yourself with either an old-skool beam type or modern-skool digital torque wrench!  But ultimately the answer is no, if they're properly torqued down, lubed or not, the won't just come 'undone' unless/until a slightly greater loosening torque is applied.

 

I REALLY appreciate that explanation! Very clear and helps a great deal in my understanding of something that was not immediately intuitive to me.

 

Cheers,

 

Doug.

[TobyB]

The metallurgy of the Turner studs simply doesn't compare to the inexpensive ones.

ASSuming they are as good as they were, they are well made, strong, smooth, and 

bullet- nosed for easy nutting.  With a nice chubby section to snug up against

the hub so they don't come out with the nut.

 

It matters when you're pulling the wheels off it 3 or 5 times a day.

 

It matters a lot less when you're doing it once a season or less.

 

Plus, the Turner version come in Long and Really Long.

 

I find that I cannot NOT use anti- sneeze, but then adjust my torque appropriately.

I just can't stand the galling and tearing that steel- on- aluminum does.

But if you simply HAVE to torque to stock torque with a clicker, don't use anti- sneeze.

Maybe motor oil if YOU can't take it either.

 

t