Replacement bolts?

2007 Mazda 6 V6 3.0l

Hi there,

I rounded off a bolt when trying to replace the AT Mount on this vehicle. I bought some vise grips, and bolt out kits for my second attempt.

I was wondering if I could use any replacement bolt from Oreilly’s or hardware store or do they have to be specific to the vehicle (OEM)?

I don’t know if there is a standard, but I am concerned about torque values here. I am afraid to apply the same torque values on the new bolts and later find out they were too tight or whatever.

Please help. Thanks

I’ve replaced many auto bolts/nuts with ones from ACE hardware.

Take the old bolt with you so that they can match the grade,length, and thread size.



Thanks Tester, will do!

You can, but if you do I’d recommend getting a “grade 8” bolt (or the metric equivalent). Here’s a chart that’ll make the reason obvious. You’re better to have a too-strong bolt than a too-weak bolt. Yes, they’re available at any big-box hardware store dirt-cheap.


Thanks a lot for the tip and the link!

On this subject, isn’t the metric equivalent of grade 8 marked 10.7?

Doesn’t your new mount come with studs or bolts?

Read here:

In metric we have:
4,6 supersoft, pretty much like butter on a hot windowsill
5,8 standard
8,8 strong, but can be stretched.
10,9 superstrong
12,9 break me if you can :stuck_out_tongue_winking_eye:

Only steel bolts are rated this way. Stainless is rated differently and has a much lower max. torque limit.

That’s why I said “or metric equivalent” and posted a chart that shows the metric ratings.

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Nope… I ordered all 3 mounts from the Mazda dealer and none of them came with bolts.

I was just over to Home Depot today looking for a fastener. They have a pretty good assortment of grade 8 bolts as well as the metric version of grade 8. Suggest to OP to look at bolt head. There are often marks or numbers on them that provide a clue what grade it is. If you know the torque spec, you can usually figure out the required bolt grade too.

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I found my local Lowes to carry a better assortment of fasteners suitable for cars.
Another non-chain hardware store in 15 miles literally has it all, but getting to Lowes 2 miles down the road gets 90% of what I usually need.

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I find the parts store rarely carry anything but grade 5, same with Tractor Supply. HD and Lowe’s do but I usually go to Fastenal or Industrial Bolt Supply. If they don’t have what you want, you didn’t need it.

The problem I find with Fastenal is, you can’t buy just one piece of hardware.

Instead, you must purchase a package of that hardware which may be a half dozen.

When you only need one.


I wonder if anyone who sells fasteners by the piece can do so profitably. TSC sells grade 5 and grade 8 by the pound but because it’s loose in bins a lot of it leaves the store in peoples pockets.

And years ago I realized how much time was being wasted over broken and missing bolts so I bought a hardware store bolt bin and stocked it with a dozen of every common size SAE and Metric bolt,nut, screw and washer and lengths of threaded rod also. And I never charged for them. The time saved not chasing replacements down or cleaning the old ones to reuse them was more costly than the new bolts.

Yeah there is that. I needed two bolts, nuts and washers to install a new exhaust on my truck. Ended up with 3 bolts, 5 nuts and 10 washers.

Edit: but they had them when no one else in town did.

Buy single pieces here:

That does no good if you need the piece of hardware NOW!


Thank you, Captain Obvious…


I think you should change your handle.

Because you’re not.


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