Looking for a source for Metric Carriage Bolts

I would call a nut and bolt store. Houston has a few. I imagine more industrial cities have even more. However, Houston is mostly without power so it may be hard to call here.

I am looking for what I would call a carriage bolt, except that it has a round spline under the head instead of a square shape that is usually under the head of a carriage bolt. The round shoulder under the head is a fine spline about 8 mm long.

The bolts secure a steel gas tank support arm to the frame of a truck. Threads = 10 mm OD X 1.5 mm pitch Length under head = At least 40 mm ; can cut down a longer bolt if needed. Head diameter = Approx 20 mm, but can use a little larger if needed. Grade = Prefer a 10.9 class or whatever is the strongest grade available. The round spline shape under the head has an 11 mm OD.

I need a source of supply I can order from here in the USA. I tried local hardware and autoparts stores along with

I also looked through the catalog but have not found anything yet. Does anyone have an idea of where I might find this? ____________________________________________________

Try those sources again, (along with Fastenal, which has acquired many hardware firms) using different nomenclature.

What you are describing sounds like a shoulder stud or a lug nut stud. They are made of high strength steel and the splines keep them from turning after they are pounded into a close-fitting hole in steel. The stud head diameter is typically about 20 per cent larger than the stud body, not the 100 per cent you have in mind.

Good luck.

Rodan.

Something like this (just the first picture showing two different sizes)? Wheel studs seem to be what you're looking for:

Thanks for your replies guys,

BuckerooBilly, yes, they look just like wheel studs (with a fine spline) but with a standard round carriage bolt head.

It's not what they call a "ribbed neck" carriage bolt because the spine is too course and long. The splines on these bolts are short and fine just like on a wheel stud.

I will use the search terminology suggested by Rodan, if that does not work I will probably just use a 7/16" OD grade 8 hex head bolt with a washer under the head.

John

Could be it's a fastener just made for your particular model and function, and I don't really understand having a reason for a doomed head, most splined lugs and exhaust manifold stud I've run into are flat across the top. What model is it, and have you tried having a dealer service parts department look around their graphics for it?