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ESSX28-1 · ESSX28-1 November 2010 Posts: 995Platinum Member

I'm looking for a source for 7/16 x 2 1/4 coach bolts ( carriage bolts?). They are dome headed with a square section at the top of the shank. I prefer the thread to be machined on rather than rolled but cost may determine what I get. The source needs to be prepared to sent these to New Zealand unlike McMaster Carr. I'm seeking 16 of these.
Thanks guys.

Tallent R

That's a common hardware store item here. I would think any big
home supply place here would send you some. I know "Home Depot" has a
on line store as does "Lowes". Use Google or Yahoo to search for them,
Roger

Hudson308

I always thought rolled threads were stronger? At any rate if you can't find any place that will ship these direct, email me and I'll try to box em up and ship em to ya. Can't be too much trouble as long as I don't put any gunpowder in with em.

Scott

Try these folk's.

http://www.restorationspecialties.com/

GrimGreaser

Rolled threads are always superior to cut threads. Forming the threads work-hardens the material and creates favorable compressive residual stresses at the thread roots. The material's grain is reformed rather than interrupted by cutting. But, if the bolt is non-critical or lightly loaded with no fatigue loads than machine cut threads are fine and cheaper.

Thus concludes your short screw and fastener lesson for the day.

Hudson308

GrimGreaser wrote:

Rolled threads are always superior to cut threads. Forming the threads work-hardens the material and creates favorable compressive residual stresses at the thread roots. The material's grain is reformed rather than interrupted by cutting. But, if the bolt is non-critical or lightly loaded with no fatigue loads than machine cut threads are fine and cheaper.

Thus concludes your short screw and fastener lesson for the day.

Now, see? I knew rolled threads created favorable compressive residual stresses. Yeah, that's it. Knew it all along. :whistle:

GrimGreaser

I did spend a lot of money for this fancy education... I don't get many chances to show it off.

Geoff C., N.Z.

Rolled threads may be stronger, but the problem is that the threaded section is fatter than the stem of the bolt. In this particular application, where the bolt holds the wood wheel to the hub, if you use a rolled thread bolt the stem is somewhat smaller than the hole. The original bolts were a tight fit in the hole through the wood.

ESSX28-1 · ESSX28-1 November 2010 Posts: 995Platinum Member

I understood that a rolled thread meant that the thread diameter was greater than the shank diameter thus being difficult to achieve a tight fit through the hole & that a machine cut did not have this characteristic.

GrimGreaser

Ah, I see why you need machine cut threads.

The rod stock that makes a formed bolt is slightly smaller since material will be forced out of the roots and into the crests of the thread. I was just addressing the strength aspect.

essexcoupe3131

Hi David, are these for your wheels?

Mike

ESSX28-1 · ESSX28-1 November 2010 Posts: 995Platinum Member

Hi Mike
Not for the Essex but for a friend's early Dodge wheels.

Dave

essexcoupe3131

If they are the same as a Essex I have a whole lot that have been chromed

Mike

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