Obviously, the square, rectangular, or oval shoulders under the head all serve the same primary purpose I would think....anti-rotation to torque.� So, not sure what your needs are, but there are other useful ways to add anti-rotation to a fastener--like pinning with a cross-holes (dowel pin) for example.� Uhh-h-h....maybe even Loctite....depends on what you are doing, materials involved, amount of anti-rotation desired.� Spot-weld?

And I guess you could make your own rectangular shoulder with file and a vise.� But all depends on if you want to make the side of the square longer or shorter, right?!

Also, there may be an option with a third component, like some sort of washer with....a square hole (ID) to fit your bolt but a rectangular feature (OD) to fit your situation.

Need more specific information to solve.� Think outside the box?� Yeah....we do that here.

Rich
San Diego

--- On Thu, 5/12/11, Alistair Bell <albell@SHAW.CA> wrote:

From: Alistair Bell <albell@SHAW.CA>
Subject: Re: Modified carriage bolts?
To: vanagon@GERRY.VANAGON.COM
Date: Thursday, May 12, 2011, 6:21 PM

there is an oval shouldered one in this handy ref doc on my blog

http://shufti.files.wordpress.com/2010/06/jg.pdf

alistair

On 12-May-11, at 6:08 PM, Rocket J Squirrel wrote:

> Carriage bolts have a short square section of shank under the head.
> They
> are used in square holes.
>
> Is there such a thing as a carriage-type bolt that has a rectangular,
> rather than square, section under the head?
>
> --
> Rocky J Squirrel
> '84 Westfalia: Mellow Yellow ("The Electrical Banana")
> '74 Westrailia: (Ladybug Trailer company, San Juan Capistrano, Calif.)
> Bend, OR
> KG6RCR