Jump to content

Cost of bolts - BMW vs Bolt Depot


worzella

Recommended Posts

I need the 24 M8x55 hex head bolts to attach the rear axles to the diff and stub axles. Most of the official BMW parts suppliers charge about $3.50 per bolt, but on the Bolt Depot site I see M8x55 hex head 12.9 grade for 0.38 cents each..... Is there something really special about the OEM BMW bolts.... has anyone used a cheaper alternative?

 

I completely understand this is a critical attachment, but the cost difference is an order of magnitude.

 

Thanks

Link to comment
Share on other sites

I need the 24 M8x55 hex head bolts to attach the rear axles to the diff and stub axles. Most of the official BMW parts suppliers charge about $3.50 per bolt, but on the Bolt Depot site I see M8x55 hex head 12.9 grade for 0.38 cents each..... Is there something really special about the OEM BMW bolts....

yes...the price...

 

I like McMaster-Carr as they seem to have the best selection of hardware. Here is a box of 25 for $7.19

 

 

http://www.mcmaster.com/#socket-head-cap-screws/=uqm4g6

+1  great prices and i get stuff the next day.

Link to comment
Share on other sites

Another popular (and much cheaper) idea is replacing intake/exhaust manifold studs with 'metric socket set screw cup point' studs. (M8x1.25x40mm fits most applications, coolant housing stuff may need different lengths, etc)

Nothing but an allen wrench/socket needed to remove them, and they come in oil finish which looks wicked in contrast to the aluminum head.

Edit: I was just thinking this weekend about compiling a list of the most commone bolts/nuts for my car and getting a decent supply going. May be expensive on front end, but cheaper than BMW, and ready to go.

Link to comment
Share on other sites

Ha.  Ha ha.  hahhahahahah...  yeah, I used  'metric socket set screw cup point' keyway setscrews

once for an exhaust manifold.  Within about 2 months, most had snapped off.

They didn't like the expansion/contraction cycling, apparently.  Bugger to get the remains out, as they were pretty hard and

brittle...  which makes sense, as they're designed to drive into a mild steel shaft.

 

I don't recommend it.

 

And as to buying cheap hardware... well, if you're replacing the nuts that hold the dash on, sure, it doesn't matter.

But if it's anything loaded, subject to cycling stress, or that might kill me if it came loose, I tend to shy away from

the generic.  Because I have absolutely no idea what I'm buying, and a pretty good idea from whence it came.

 

So yeah, for the flywheel, driveshaft, CV axles, brakes, things like that, I tend to suck it up and buy things of

'known' provenance.  It's not a guarantee, but it's a lot less of a gamble... 

...and if I ever have the choice between a used BMW bolt that's not destroyed and new from Home Depot,

I'll ALWAYS reuse the BMW fastener.  Again, it's a lot less of a gamble.

 

That said, BelMetric, and McMaster both have decent reputations.  For almost anything but flywheel bolts

and E30 front caliper bolts, I'd  be a lot less worried about their stuff than BoltMasters.  But I'd still use

used good BMW fasteners over 'em... just because they can't test every box that comes off the truck...

 

t

paranoid.

 

Really.  There is a lot of cheap crap out there, and I only get to die once.  I'd rather have it be over something

a bit more worthy than a $3 fastener.

Link to comment
Share on other sites

Ha. Ha ha. hahhahahahah... yeah, I used 'metric socket set screw cup point' keyway setscrews

once for an exhaust manifold. Within about 2 months, most had snapped off.

They didn't like the expansion/contraction cycling, apparently. Bugger to get the remains out, as they were pretty hard and

brittle... which makes sense, as they're designed to drive into a mild steel shaft.

I don't recommend it.

Ooohhhhh.... Well, thank you for the heads up!

Link to comment
Share on other sites

+1 TobyB !!!!

 

from an engineering perspective:  Bolts are not "bolts" ...... which is to say, you've got metallurgy to consider.  Which translates to material of manufacture, and strength of material.  

 

Whatever bolt you are replacing, you want a bolt that is "Equal" or "Better" ..... meaning material, yield strength, ductility, ANSI rating, and a few other engineering terms I've long since forgotten since Mechanical Design 301 & 302.

 

So be very careful and thoughtful when replacing those bolts that really do have to hold things together without failing.

 

Cheers,

 

Carl

Link to comment
Share on other sites

I sort of subscribe to Toby's approach. Fortunately, I've been able to clean-up and reuse the half-shaft to diff bolts so I didn't have to buy new, but I've found that if I only need 1,2, or maybe 3 or 4 of a specific fastener it's cheaper to get them from the dealership because there's no shipping fee.

And, here in AZ, the dealer's BMW CCA discount covers the taxes, so that aspect is a push.

Bob Napier

Link to comment
Share on other sites

I sort of subscribe to Toby's approach. Fortunately, I've been able to clean-up and reuse the half-shaft to diff bolts so I didn't have to buy new, but I've found that if I only need 1,2, or maybe 3 or 4 of a specific fastener it's cheaper to get them from the dealership because there's no shipping fee.

And, here in AZ, the dealer's BMW CCA discount covers the taxes, so that aspect is a push.

Bob Napier

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Upcoming Events

×
×
  • Create New...