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Spring U-Bolts

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Does anyone know a source for spring U-Bolts?*

These are for a 1-3/4" wide spring, and have a 7/16 thread, originally forged. (trying to figure out how to post a photo from my phone!)

There are so many variations, so it does not surprise me*

that there is not a supply Uof them. Originals are nearly always bad. It's a lot of work to investment cast and machine a few. *These fit in tight quarters so need to be quite accurate dimensionally. * *Any ideas?

Tom Rasmussen - for my 1910 Franklin

Sent from my iPhone

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Our local parts store has a company they get U bolds special order from. I had them get some made for my 57 Chevy pickup and they did a great job and the expense was very minimal. It took two days and matched the originals.

I don't know what your shackles look like but whatever they look like a basic shackle made to fit properly can probably be made to look like the originals with some addition of some metal through brazing or welding onto the new shackle and, then careful grinding and filing or die grinding. Then paint it. If it wasn't painted originally, then paint it to look unpainted with some Eastwood paint to match.

If you can post a picture I can tell more. I am not sure I would want a cast part for this application.

Jim43 dstamp4@comcast.net

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Tom , Look at the Amish wagon and carriage builders/restorers. Those squared u-bolts are still made.They have all the square nuts,bolts, and early hardeware . Mike

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Thanks Mike. The Amish axle bolts are great and fit the front axle of a cross engine Franklin great but are too small for a bigger brass car. I think I am going to have to cast them but am open to alternatives.

Tom Rasmussen

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Tommy, how about some from a series 11 or so? There are more than just a few around. JR

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Good thought John. I can check the newly-available drawing file to see if any later bolts might have te same dimensions.

Tom

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I got a machinist to make me a stainless U-Bolt for my 1921 Peugeot. I assume he used a milling machine. It looks good. Once painted, it looked vintage.

Phil

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Somewhere out there in literature land is an article about fabricating your own u-bolts, and it's not that difficult. I want to say it's in an issue of the HCCA magazine.

You probably don't want to have this piece cast, as a cast part can be brittle.

You start with square stock steel, the width of the u-bolt you need. Calculate the total length needed, thread to thread, with measurements across spring and down each side to axle. Add to this length the length needed of threads, and cut the sqaure stock to this length. Machine each end to round and thread, each to appropriate length. Clamp bar stock in a vise, heat, and bend one side 90 degrees, make a jig for vise if needed and repeat other side. Take a grinder, and change square shape to half oval shape.

Like magic, you have your new shackles!

And yes, they are hard to find, and not many people fool with making and selling them....

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You need to do some simple arithmetic to make them a correct fit. I mill a flat on a correct length of 4140 steel bar, to give the width of flat were the U-bolt sits on the spring. Then I accurately mark and centre-drill both ends, then turn them down to diameter and cut the threads in the lathe. Next step is mill to remove the excess from the side opposite the first side I milled.

I have made a bending jig of the same width as the spring, with corner radii and a cross piece to line up square. With the length either side equalised with calipers, and using a block on top I put about 20 ton on with the hydraulic press to hold the workpiece for an accurate bend. Then I heat to a dull red heat with the big oxy-acetylene torch, and flog the ends around against the forming block with a suitable heavy hammer. When cool, you do the cosmetic shaping by eye with a piece of precision workshop shaping equipment, a quality heavy duty 5 inch angle grinder with a medium zirconia grit flap wheel. It took about 15 minutes each for this finishing step with my front U-bolts for the 1911 Napier. With that common grade of good high tensile steel the U-bolts have a nice ring when finished, but probably should be professionally heat treated if it is a racing car. I would not recommend casting, fabrication by welding, or making them out of mild steel. This method should be as clear as mud, but I can take a set of photos and ask my son to insert them on the forum if anyone wishes.

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I am curious as to why several of you are opposed to casting. You can get parts cast in 4140 and then heat treated if necessary at reasonable cost. That seems to me to be the way to go if you need to make more than a couple. I think I would have more of a concern with bar stock failing after being heated, cooled, bent and beaten into submission.

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There is one very good practical reason to make these from pre-machined and threaded alloy steel stock rather than cast steel blanks: That is the difficulty in machining the thread accurately when it is in U-form. With the "Globalisation"of manufacturing industry the foundries with technical capability of making anything in alloy steel, let alone willing to do this in lots of 4 small items, are about as prolific here as the dodo bird. Machining and cutting ends of bar stock in the lathe is easy. I have always found it possible to screw-cut a thread while conversing if someone is there. Your stated sequence of heating, cooling, bending, and beating is not what I described. I heat to the lower end of the plastic range, then forge;

and there is no shock cooling because the steel block the U-bolt is forged upon becomes very hot too. I commend to you a book by a Californian, Alexander Weygers, which is titled

"The Modern Blacksmith". I just checked one of the book sites for you, and it is available from $13 plus postage. This even teaches you how to do your own heat treatment of steel if it is necessary. Knowledge and modest ability in the craft of the blacksmith is as beneficial or necessary at times in restoration of antique cars as it was when they were built. There are only four U-bolts of one type per end of a car as a rule. That may not be a good return for the time in making a nice pattern. Everyone has to decide how they prefer to do a particular job. As Henry Leland was kind enough to explain to the English when Cadillac first was awarded the Dewar Trophy for the demonstration of interchangeability of parts of the single cylinder Cadillac: "It is really a simple process. First you have to decide what you want to do and how you are going to do it. Then you do it the way you decided". Having started my ownership of cars with a fork & blade rod Cadillac, (and with an early Lincoln from Perry Smith on ship to me right now), I always remember Mr Leland's advice when I have a restoration problem.

Incidentally, in reference to casting steel components; Morris Burrows told me that those mile-long conrods for the L-head Mercers are actually cast steel. There is no problem in those; but the forged, tapered, lightend conrods of the Rochester-Trego ohv 6 cylinder Series 6 Mercers have design problems, and are rubbish that we believe no-one should run any more if they value their car and engine.

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I wonder if the Mercer con rods are "steel castings" or if they were made of "cast steel." As confusing as that sounds, "cast steel" is the traditional name for crucible steel and refers to the manufacturing process of the metal, not the item the metal was made into. Its an endlessly confusing issue in the antique arms & armour world. In the mid 19th century "cast steel" always refers to the material but as it became possible to actually make castings out of steel the use of the term became more and more ambiguous. Are the Mercer rods machined all over? If so, I'd suspect that they were machined out of solid pieces of a high grade of crucible steel (aka "cast steel"). Forging is the other premium option but its not cost effective if the quantities involved are small - though companies like RR did it that way.

Edited by JV Puleo (see edit history)

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I'd like to see photos of forming the U-Bolts, Ivan. My Peugeot had them made from bent threaded rod from the hardware store. I got some new ones made, and wondered how it was done.

Phil

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