novaderrik wrote: i guess they could have done a 12 point nut instead of a boring old hex nut, but costs become a consideration...
right... $0.13 standard allen head or... $3/unit special fastener that has to be designed. They probably didn't put as much thought into the issue as this thread has.
codrus wrote: Put a little bit more materal on the part to raise the bolt head up to the level of the webbing, then use a normal hex-head bolt. Now you don't need all that specially engineered clearance outside of it because you can use a box-end wrench on the bolt.
Sure. I'm sure the Bosch folks were keen to redesign an off-the-shelf sensor for BMW for free so BMW could swap one common type of bolt head for another.
This is completely a previous-owner put a damaged fastener back in problem, not a wrong application for the fastener situation.
It is way easier to start an internal hex on a T handle in a blind hole than to get a wobbly external hex going inside a socket. I doubt they took that in to consideration but... maybe. They are German.
Jaxmadine wrote: The germans are still mad about the war...
Don't mention the war!!!
There's a kind of logic to the way some of these fasteners are used.
Like VWAG uses Allens in certain spots, hex head in certain other spots, and XZN in certain other spots. Allens hold things to subassemblies, hex head hold subassemblies together, XZN is on drivetrain components.
Color me a fan of XZN. They don't strip out under heavy torque like Allens do. Most of the force is against the point, and they have twice as many points available, as a more favorable angle than a normal 12-point fastener - 90 degree instead of 60 degree. Really it's more like with the XZN the torque is against the flats moreso than the corners.
I've never rounded out an XZN bolt. Have had plenty of practice on them too 
mad_machine wrote: I have become very accustomed to Torx. I have actually begun to appreciate them
Anti-Christ!!! Bah!
Knurled wrote: There's a kind of logic to the way some of these fasteners are used. Like VWAG uses Allens in certain spots, hex head in certain other spots, and XZN in certain other spots. Allens hold things to subassemblies, hex head hold subassemblies together, XZN is on drivetrain components. Color me a fan of XZN. They don't strip out under heavy torque like Allens do. Most of the force is against the point, and they have twice as many points available, as a more favorable angle than a normal 12-point fastener - 90 degree instead of 60 degree. Really it's more like with the XZN the torque is against the flats moreso than the corners. I've never rounded out an XZN bolt. Have had plenty of practice on them too
I replaced them with standard Allen heads on my cars.
http://www.harborfreight.com/12-piece-screw-extractor-set-40349.html
I linked the HF one instead of the fancy snapon or matco ones that probably work better, becuase I know which one you guys are actually going to buy :).
Josh wrote: I linked the HF one instead of the fancy snapon or matco ones that probably work better, becuase I know which one you guys are actually going to buy :).
Streetwiseguy wrote: Go back in time and don't buy German cars that use soft allan head bolts. Hammer in a torx or an EZout. Every German car mechanic needs a good selection of EZouts for this very reason.
EZouts are only EZ when they dont break off. I've had a lot better luck with those fluted/rifled socket things.
Tyler H wrote:Streetwiseguy wrote: Go back in time and don't buy German cars that use soft allan head bolts. Hammer in a torx or an EZout. Every German car mechanic needs a good selection of EZouts for this very reason.EZouts are only EZ when they dont break off. I've had a lot better luck with those fluted/rifled socket things.
I meant these, and I think you did too. They are perfect for rounded allan head bolts.
These are not so ludicrously priced as to drive away GRM readers:
http://www.amazon.com/53226-32-Inch-Multi-Spline-Extractor-Assortment/dp/B0002NYBHI
I have a large set of the Irwin external bolt extractors and the have saved my ass numerous times, so these are now on my wishlist (I already have a Kobalt extractor set similar to the HF set I linked, which work fine, but these look like they would be much better for shallower holes).
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