Are header bolts special?

[Buffalo Bill]

Looks like I can save $2 a bolt plus shipping if I just buy bolts at the hardware store for the headers.
Are header bolts special, or just like a standard bolt?

[posplayr]

There are many types of standard bolts. Header bolts are also a type of standard bolt.

I would recommend stainless steel and many people used stainless studs made of all thread. These are also standard types.

[Nessism]

The stock screws have a "7" imprint in the head, these are similar to a SAE Grade 5 hex head screw. I think the equivalent designation is metric 8.8. Don't use anything weaker.

[Buffalo Bill]

So, there is no special temper or steel used for header bolts, they are equal to 8.8 bolts?

[60ratrod]

Nope. If going with stainless, make sure you use anti-sieze. It will help when you have to pull the pipes and reduce the amount of corrosion that can build due to dissimilar metals. Stainless steel and aluminum don't get along, especially when an electrolyte is introduced. We had a jet on deployment corrode a huge hole in the fuselage due to a stainless steel patch a repair artisan installed just before we got the jet

[chuck hahn]

They can be no longer than the originals from the bottom of the head to the end of the threads otherwise they stand a chance of breaking thru the head into the oil gallies. Think its like 35 MM tops.

[Buffalo Bill]

60ratrod; Bummer about the jet on deployment, but I'll remember that picture. That's inter-metal ionic decay.
Chuck I was waiting for you. Hey 35mm is exactly the size I think I'll need, that's 10mm for the collar flange and 15mm into the block.
Looks like bikebandit wants $3 for each bolt, plus another $3 for the washer???

[chuck hahn]

Get them at the local supply house. I get them from Fastenal myself. Take one with you to get the right thread pitch.

[chuck hahn]

Not any special hardness or anything if that was the question.

[60ratrod]

You can probably get them from a local napa, ace, or like chuck, fastenal, just depends on what you have near you. And the aircraft was only down for about 2 weeks while the repair artisans repaired it correctly. Most know i will sing about corrosion just because of what i have encountered. I'd hate to see someone loose a motor due to corrosion. These things aren't getting any easier to find

[CrazyCloud]

10.9 grade metric bolts are usually available at home centers, they are roughly equivalent to grade 8 standard bolts and are stronger than metric 8.8 grade. They are higher carbon steel and tempered, good insurance against breakage for a few extra pennies. Stronger than most stainless fasteners.

[Nessism]

10.9 grade metric bolts are usually available at home centers, they are roughly equivalent to grade 8 standard bolts and are stronger than metric 8.8 grade. They are higher carbon steel and tempered, good insurance against breakage for a few extra pennies. Stronger than most stainless fasteners.

One thing to pay attention to is that many generic metric fasteners have an odd number hex size, 13mm hex head instead of 12mm for example. Header bolts are located quite closely to the header pipe, sometimes in close proximity to the frame down tube. The larger 13mm socket you need to tighten the screw may be just enough to increase difficulty in getting the screws properly tightened. Not sure if this applies for all bikes or what have you, but something to consider if you purchase generic hardware.

BTW, CrazyCloud makes a good point. Stronger is better since those header bolts love to sieze in the head. Use anti sieze and a strong grade bolt. I would avoid ungraded fasteners or low end stainless.

[Buffalo Bill]

No stainless for me, but high grade bolts yes.
Both my Suzukis use allen head bolts, so no clearance problem.
I always use anti sieze, and because they're allen head, I don't torque them much above 10ftlb.