Why do auto parts stores not carry bolts needed for cars

4WD

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13,587
Location
Texas
I get lots of grade 5 and grade 8 plated bolts at TSC …
subbed some metric for SAE on my winch installation .
 
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3,147
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Parts Unknown
My daughters BMW bolt broke that holds the bracket for her tensioner pulley.
OMG a nightmare getting the bracket off to remove the bolt. Its the entire oil filter housing bracket.
M8 bolt 110 mm long(4 1/8 )
Advanced or napa did not have it. Couldn't even offer to get one.
This is a grade 8.8 bolt, I guess this is a standard metric grade.
I ended up getting two at ACE that was a bit longer and will be cutting 1/4 off it so it wont bottom out.
Just venting why auto parts stores don't have what we need to repair our cars.
Bolts are difficult to comprehensively stock for all makes and models for auto parts stores. They only carry what they think they can reasonably sell and make some sort of profit on.

I don't expect auto parts stores to carry triple square bolts that VW & audi likes to use.
 
All u have to do is go to mcmaster carr (Google it) they carry just about every fastener known to man, including those goofy VW triple square head bolts. You already know the size just choose the material and grade you need. I had to order 12 rear cv axle flange bolts found them in grade 12.9 and had them delivered in 48 hours. Simple easy and cheaper anybody else including shipping. Plusat least the ones i got where US made with certifications not the crummy chinese junk that most places carry, since fastener failure would be catastophic especially at speed. Look them up you'll be amazed at what they carry.
 
Last edited:

JHZR2

Staff member
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44,548
Location
New Jersey
I ran into this today with a seized flange bolt/nut.

Auto parts stores had nothing. The good “non-corporate” local hardware store had very close but no cigar, too short for the “right” option.... but was able to finagle something else as good enough.

HD and lowes don’t have enough or as consistent stuff in their fasteners sections.

Aanother reason to support your local real hardware store.
 
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4,113
Location
SW Ohio
110 MM length is not a common size. Many metric bolt manufacturers stop at 100mm long.
What people should realize is that when something is being designed, you almost never make up 'hardware' on the fly, i.e. nuts, bolts, bearings, o-rings, etc, etc. These are all standardized parts (modern CAD software have "libraries" that you can select from*) and you will either use a standard part, maybe that means drilling / tapping a little deeper, if possible, or modify the part this hardware fits on. If you have a cylindrical part that has a bearing or bearings, you increase or decrease the diameter to match the req'd specs of an existing bearing. This means you order off-the-shelf parts from SKF, NTN, etc. That same bearing may already be used on other parts you make too.

Manufacturers really don't want "special" parts if they can avoid it. It costs them more as well.

* When I refer to selecting from parts in a library, you can design a shaft and in assembly mode in the software, tell it you need to add a bearing. You tell it where it goes and the software will actually match up standard bearings that fit or are close to fitting. Companies can modify these libraries to include only their own standard, stocked parts too.
 
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6,856
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California
What people should realize is that when something is being designed, you almost never make up 'hardware' on the fly, i.e. nuts, bolts, bearings, o-rings, etc, etc. These are all standardized parts (modern CAD software have "libraries" that you can select from*) and you will either use a standard part, maybe that means drilling / tapping a little deeper, if possible, or modify the part this hardware fits on.

* When I refer to selecting from parts in a library, you can design a shaft and in assembly mode in the software, tell it you need to add a bearing. You tell it where it goes and the software will actually match up standard bearings that fit or are close to fitting. Companies can modify these libraries to include only their own standard, stocked parts too.
I think I’ve seen those libraries in AutoCAD and SolidWorks. Most automotive CAD is done in SolidWorks and Autodesk’s AutoCAD/Fusion/Inventor but the high-level CAD is done in CATIA, owned by Dassault Systemes who also owns SolidWorks. CATIA of course, being the main CAD platform at Airbus and Boeing - the mismatch between versions of it being famous for delaying the A380.

with the rise of 3D printers for rapid prototyping, the consolidation of the supply chain and the OEMs wanting to consolidate and simply their platforms and bill of materials, there will be more commonality of major components which helps bring down the cost of goods sold.
 
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4,113
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SW Ohio
Most automotive CAD is done in SolidWorks and Autodesk’s AutoCAD/Fusion/Inventor but the high-level CAD is done in CATIA, owned by Dassault Systemes who also owns SolidWorks.
I've been out of the game for a few years but I don't think Inventor or Solidworks are capable enough (I was a pretty competent Inventor user so I'm not knocking it). Suppliers that produce/supply parts that the big automakers buy very well may be using those software packages though. CATIA and UG are what they (GM, Ford, etc) use, to my understanding. In fact, I seem to recall that either GM or Ford (leaning towards GM) drove the development of a CAD package that they used in-house originally and later sold off and became CATIA, UG, or some other.

and the OEMs wanting to consolidate and simply their platforms and bill of materials, there will be more commonality of major components which helps bring down the cost of goods sold.
I was a designer at one of the biggest (chemical) pump manufacturers and we were ahead of that game for decades actually. When I referred to bearings and o-rings above, we had very common shaft designs, at least on the "power end". It was a proven, reliable design and we did not change it. On the impeller/sealing end, we had to make variations there though.
 

tblt44

Thread starter
Messages
469
Location
FL
All u have to do is go to mcmaster carr (Google it) they carry just about every fastener known to man, including those goofy VW triple square head bolts. You already know the size just choose the material and grade you need. I had to order 12 rear cv axle flange bolts found them in grade 12.9 and had them delivered in 48 hours. Simple easy and cheaper anybody else including shipping. Plusat least the ones i got where US made with certifications not the crummy chinese junk that most places carry, since fastener failure would be catastophic especially at speed. Look them up you'll be amazed at what they carry.
I am aware of mcmaster carr. I work in a machine shop and we order from them but when I need something today I guess ACE is the place
 

Pew

Messages
1,030
Location
Illinois
I've had better luck with O'reillys carrying automotive bolts versus any other car part chain stores including Advanced Auto, AutoZone, and (surprisingly) NAPA.
 

JC1

Messages
4,789
Location
Oshawa, Ontario Canada
Just go to the dealer? We have most hardware in stock because 90% of the fasteners on BMW are torque to yield, single use. Even changing the air filter in a new M2 Comp, or M3/M4 requires about $200 in fasteners.
Problem is the dealer's prices. For the Honda bolts for the rear lower control arm they want $21 each. Even the Honda parts guy said to try and get them somewhere else. I know they gotta stock them etc, but paying over $120 for 6 bolts when I only paid $100 with shipping for both control arms, I don't think so. My car isn't going to Barret Jackson anytime soon.

I bought a bunch of nuts, bolts and washers and extras just In case and it cost me $53.
 
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1,803
Location
Ontario, Canada
Problem is the dealer's prices. For the Honda bolts for the rear lower control arm they want $21 each. Even the Honda parts guy said to try and get them somewhere else. I know they gotta stock them etc, but paying over $120 for 6 bolts when I only paid $100 with shipping for both control arms, I don't think so. My car isn't going to Barret Jackson anytime soon.

I bought a bunch of nuts, bolts and washers and extras just In case and it cost me $53.
Find an online dealer that sells for less.
 
Messages
4,113
Location
SW Ohio
You would think rockauto would offer tons of different sized fasteners, but it doesn't appear to be the case.
It just doesn't make sense from an economic sense for them (or their suppliers actually) to stock what are effectively, and rightly so, almost "dealer only parts". A particular fastener may only be used on one vehicle model for a component that rarely needs replaced.
 
Messages
127
Location
Iowa
My daughters BMW bolt broke that holds the bracket for her tensioner pulley.
OMG a nightmare getting the bracket off to remove the bolt. Its the entire oil filter housing bracket.
M8 bolt 110 mm long(4 1/8 )
Advanced or napa did not have it. Couldn't even offer to get one.
This is a grade 8.8 bolt, I guess this is a standard metric grade.
I ended up getting two at ACE that was a bit longer and will be cutting 1/4 off it so it wont bottom out.
Just venting why auto parts stores don't have what we need to repair our cars.
simple reason is it would cost too much and they lose valuable floor space for higher margin items. Hardware is unique to most manufacturers. BMW would be able to get the bolt for you...

Just my $0.02
 
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