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View Full Version : Where to get Copper Bolts?



CCWKen
09-26-2006, 12:29 AM
I need some copper bolts to replace the binding posts on some antique starters and switches. I've checked the usual places and my favorite auto suppliers but nothing. I need 3/8 x 1 1/2 - 16 if anyone has a supply.

Willy
09-26-2006, 12:39 AM
Ken,try these guys...http://www.pin.ca/premiere/capab.htm

TECHSHOP
09-26-2006, 12:41 AM
It is getting late on the east coast, but I would try an electrical supplier or a nautical hardware supplier, of course you could always make some.

JCHannum
09-26-2006, 08:08 AM
Pure copper may be difficult, but McMaster Carr has silicon bronze HHcap screws available. Silicon bronze is 95-98% copper, it is harder then pure copper, which might be to your advantage.

It is also available at marine suppliers. McM part number 93516A629. www.mcmaster.com

CCWKen
09-26-2006, 03:12 PM
Thanks guys but it looks like I'll have to make them. I located the silicon bronze bolts but they're mostly for marine applications and have poor electrical conductivity. Besides having too much resistance, I think they would be hard to solder.

I think what I'm after is Tellurium Copper (C14500). For the small amount I need right now, I may just copper plate some stock HH cap screws. I'm off to the feed store to pick up some copper sulfate (electrolyte).

TECHSHOP
09-26-2006, 03:18 PM
I don't know if this is a "dead end" but I think that "ETP copper CA110" may be the metal you are looking for, not sure how it machines. Supposed to be the next best thing to silver in conductivity, and it solders well.

J. R. Williams
09-26-2006, 04:35 PM
Ken
I would go to MSC and purchase Silicon Bronze bolts for that purpose. They are very strong when compared to pure copper. I use the SIBR bolts, nuts and washers on welding equipment I fabricate.

JRW

John Stevenson
09-27-2006, 03:47 AM
Ken,
I do a fair amount of repairs on electrical brush gear and most have brass screws fitted as being not so soft and liable to strip as copper.

Would that be an alternative to you ?

.

Scishopguy
09-27-2006, 02:50 PM
Pure copper may be difficult, but McMaster Carr has silicon bronze HHcap screws available. Silicon bronze is 95-98% copper, it is harder then pure copper, which might be to your advantage.

It is also available at marine suppliers. McM part number 93516A629. www.mcmaster.com

Jim brings up a good source here. I have found a lot of unusual and specialty hardware at West Marine. It is a national chain store that carries fasteners in bulk where you buy what you need by the piece. I have bought fine thread bolts and lock nuts in stainless steel (18-8 and 316) from them. Their assortment is impressive and they keep the supplies on hand. I am sure most big marine suppliers have the same setup. These guys are even comparable in price to the hardware catalogs.

CCWKen
09-27-2006, 11:26 PM
Thanks guys but silicon bronze is best left for building boats. This is an electrical application and the less resistance, the better. Silicon bronze is a relatively poor conductor when compared to pure copper. This will be the binding post for a starter and gets soldered directly to a field winding buss. There's not a lot of stress on the bolt other than the battery cable. The stress is in the threads to keep the cable tight.

Forgot to mention: (edit) At the far left edge of the picture is a brass bushing. You can see that stud is more on the copper end of the color.

The "bolt" looks like this:

http://img.photobucket.com/albums/0903/CCWKen/Projects/Model%20T/StarterRebuild/StarterRebuild-07.jpg

Evan
09-28-2006, 12:18 AM
The amount of resistance is a function both of the size and the length as well as the conductivity. Even a relatively poor conductor doesn't have much resistance over a very short distance. While silicon bronze is a poor conductor compared to copper the difference in actual resistance of a stud like that may be a couple of milliohms.

Have you nicked that stud with a file to see if it really is copper or just copper plated iron?

CCWKen
09-28-2006, 12:53 AM
It's copper Evan. I have what's left of the one that came off this starter when the owner was poking around inside the brush end. :eek: The buss end was just a "blob" and was all copper.

http://img.photobucket.com/albums/0903/CCWKen/Projects/Model%20T/StarterRebuild/SmokedStarterField.jpg

WJHartson
09-28-2006, 08:05 AM
Ken, if you have an industrial motor rewinder in your area they may be able to help.

Joe

JCHannum
09-28-2006, 08:12 AM
Why are you wimping out with a starter on the Model T? When the T got a starter, it became a chick car.

I can remember my father starting his with a crank. He would jack up a rear wheel, crank it to get it started, push it off the jack and chase it across the yard to get in.

CCWKen
09-28-2006, 02:50 PM
Why are you wimping out with a starter on the Model T? When the T got a starter, it became a chick car.

I can remember my father starting his with a crank. He would jack up a rear wheel, crank it to get it started, push it off the jack and chase it across the yard to get in.

http://img.photobucket.com/albums/0903/CCWKen/Personal/icon_lol.gif :D :D
It's for those hot summer days when it's 110 and don't have enough sweat left to crank the handle. :D

Starter, generator and electric lights were still an option on the '25 Touring. I'm glad the original owner sprung for the extra $60!