Looking for a source for Metric Carriage Bolts
Looking for a source for Metric Carriage Bolts
(OP)
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 www.mcmaster.com. I also looked through the www.auveco.com/ catalog but have not found anything yet.
Does anyone have an idea of where I might find something like this ?
Thanks
John
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 www.mcmaster.com. I also looked through the www.auveco.com/ catalog but have not found anything yet.
Does anyone have an idea of where I might find something like this ?
Thanks
John





RE: Looking for a source for Metric Carriage Bolts
Have you tried searching for "Rib Neck" carriage/coach bolts rather than splined? I think that's what they're called.
Good luck
Trevor Clarke. (R & D) Scientific Instruments.Somerset. UK
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RE: Looking for a source for Metric Carriage Bolts
Regards,
Cory
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RE: Looking for a source for Metric Carriage Bolts
Here's a starting point for your search, second image, second line looks like what you're after.
http://www.fastenersplusinc.com/bolts/bolts.html
Trevor Clarke. (R & D) Scientific Instruments.Somerset. UK
SW2007x64 SP3.0 Pentium P4 3.6Ghz, 4Gb Ram ATI FireGL V7100 Driver: 8.323.0.0
SW2007x32 SP4.0 Pentium P4 3.6Ghz, 2Gb Ram NVIDIA Quadro FX 500 Driver: 6.14.10.7756
RE: Looking for a source for Metric Carriage Bolts
Google turns up some Chinese suppliers.
RE: Looking for a source for Metric Carriage Bolts
Cory, yes, it looks just like your picture of a common wheel stud, except with a bigger head that looks like a standard round carriage bolt head.
It does not look like the picture shown at the fastener- plus link given by Trevor because the "ribs" or splines are too course and too long. The spline on what I need is like the fine splines on the wheel studs.
What I need is just what is shown in the picture Cory posted, except with a standard carriage bolt round head.
I tried a local store that specializes in fasteners and they said metric carriage bolts are hard to find.
Since the spline portion of the bolt is 11 mm in diameter, I might try to use a standard hex head bolt that has an equal diameter. I don't think metric bolts come with an 11 mm thread OD, (I think they generally go from 10 to 12 mm) but I could try to use a 7/16" OD grade 8 standard hex head bolt with a washer under the head.
Normally I would not give it much thought but since this is a gas tank I wanted to stick with the stock fastener. I guess there could be all sorts of reasons why they used a carriage bolt instead of a regular hex head bolt, and perhaps it has to do more with cost or assembly than function. It looks like a standard hex head would work OK.
Are carriage bolts even used for a high strength joint ? I don't think I have ever seen a carriage bolt above a grade 5.
Thanks again,
John
RE: Looking for a source for Metric Carriage Bolts
RE: Looking for a source for Metric Carriage Bolts
I guess the splines are too big/long because carriage bolts are usually intended to be fitted into wood and need the extra bite, but yours go into metal, so unless you can track down a supplier (or cut a shaped hole to fit the available types), then MiketheEngineer has the answer if they're still around
Trevor Clarke. (R & D) Scientific Instruments.Somerset. UK
SW2007x64 SP3.0 Pentium P4 3.6Ghz, 4Gb Ram ATI FireGL V7100 Driver: 8.323.0.0
SW2007x32 SP4.0 Pentium P4 3.6Ghz, 2Gb Ram NVIDIA Quadro FX 500 Driver: 6.14.10.7756
RE: Looking for a source for Metric Carriage Bolts
I just went with a 7/16" thread OD, grade 8 hex / flange head bolt and a grade 8 flanged nut.
RE: Looking for a source for Metric Carriage Bolts
www.mdmetric.com
Their website is also an excellent source of information.