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Looking for a source for Metric Carriage Bolts

Hi Everyone,

I am having trouble finding what I would call a carriage bolt, it looks just like a carriage bolt except that it has a spline round shape 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 that looks about 8 mm long.

The bolts are used to secure a steel gas tank support arm to the frame of a truck.

I need a source of supply I can order from here in the USA but I'm having trouble finding this item.

Thread specs = 10 mm OD X 1.5 mm pitch Length under head = Need at least 40 mm long but can cut down a longer bolt if needed. Head diameter = Approximately 20 mm OD, but can use a little larger if needed. Grade = Prefer a 10.9 class or whatever the strongest grade available is. The round spline shape or shoulder that is directly under the head has an 11 mm OD.

I have tried local hardware and autoparts stores along with

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I also looked through the
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catalog but have not found anything yet.

Does anyone have an idea of where I might find something like this ?

Thanks John

Reply to
John2005
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John, I found "ribbed neck bolts":

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have to contact them to see if they can supply exactly what you need. Another possibility:
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Carr has ribbed neck bolts, but only Grade 2, SAE thread =96 closest size for what you need is 3/8=94-16. I assume that you=92ve already tried getting them from a dealership or a salvage yard. There are many similar bolts if you want to search the web some more. Try: self-clinching, self-broaching, wheel bolts, spline-bolts, knurled-bolts, etc

Reply to
Denis G.

You might also try

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They have *lots* of types of fasteners

Reply to
eljainc

Thanks guys,

I think this is a custom made bolt, it's not like the "ribbed neck bolts" because the splines on those bolts are too course and long. The splines on these bolts are short and fine, like those on a common wheel stud. They look exactly like a wheel stud, except with a standard carriage bolt round domed head.

I'm just going to use a 7/16" OD thread, grade 8 hex / flanged head bolt and a grade 8 flanged head nut.

I think the only reason they used the custom fastener is to speed assembly at the factory. The splines keep the bolt from turning as the nut is torqued down, and you don't have to hold the bolt with a wrench as you torque the nut down.

Reply to
John2005

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