Roller Chain "Damascus"
Forging Motorcycle Chains into
Pattern Welded Steel
Any hints on making damascus type steel billets using motorcycle chain?
Ron - Tuesday, 07/31/01 12:11:51 GMT
Motorcycle Chain: Ron, First you put if back on your Harley, then you ride down to your steel supplier. . .
- guru - Tuesday, 07/31/01 13:13:37 GMT
- Start with clean degreased chain. A little oil will not hurt but internal rust may result in bad welds.
- Double or triple over, wire together, heat, flux and weld.
- (See Randals comments below)
- Heat (yellow) and twist.
- Double over, flux and weld twice.
- Finish the rough blank to shape by grinding to bring out the pattern.
- Harden and Temper.
- Grind and polish final finish
- Etch with your choice of etchant.
Motorcycle chain Damascus didn't work very well. it stuck in sections 1 1/2 to 2". Guess I
can scarf & weld the sections..... May be something in technique. Could you 'splain it
more slowly? I musta missed something. Used a Japanese chain, (sans "o" rings); mech
through my Harley chain in the dumpster.
Ron C - Monday, 08/06/01 12:15:41 GMT
Ron. . . I tried using motorcycle chain a couple times.
I made 3 folds, wired them as tight as I could.
Heated to a little beyond cherry (relative term depending on the ambiant light in
your shop)and beat it a bit to close up the spaces.
Apply Lots of flux and reflux. It does not all weld up tight.
Draw it out and fold..flux and weld again.
You may have to fold a few times to get rid of the holes (spaces between the links).
It turned out ok, more of a novelty than a working knife/tool.
Machinerys Handbook lists about 3 different metals used in drive chain.
That may be part of the problem in getting a good weld.
R. Guess - Monday, 08/06/01 21:14:07 GMT
Motor-Cycle Chain Damascus: Ron, I've never made it but I'm told that the key is to flux,
flux, flux and more flux. Forge welding is an art and takes practice and more practice. I
know there are a lot of folks that make motorcycle chain Damascus but I don't really get
it. The probability of having good sound welds are the way through is very low.
O-Rings in the chain? That must be new. I've specified a lot of roller chain and none had
seals. There ARE varietys with sintered (powder metal) rollers that absorb oil. But I don't
think they use it on motorcycles because the chain must be derated for the size.
Hugh Hunter says,
Most modern bikes above 250cc (ie since 1987) have O-ring chains.
The chances of removing all the nitrile based rubber before forging is slim.
Best to go for small sizes of chains as they are less likely to be O-ring.
You may need to degrease better. I'm told light oil like kerosene doesn't hurt but heavy
grease may burn and be resistant to the flux. Plated chain would also be a problem. If the
welds are sticking in sections then you know it can be done. You may not fluxing enough
or letting coal contaminate the metal at the fire fringe. If you are using coal that shiney
black deposit that gets on pieces at the fringe of the fire is vaporized coal volitiles that
have condensed and plated the cooler metal. This stuff is VERY hard to get off and flux
won't do anything for it in the interior of the chain.
- guru - Monday, 08/06/01 13:17:57 GMT
Guru and/or Grandpa. . .I have forge welded some motorcycle chain for a knifeblade. I
started with the pins facing vertically. The weld was successful except for one small
section on one end.
Will folding, twisting or surface manipulation improve the pattern?
What metals were used in old Indian and Harley chains?
Any information on the subjsct would be very helpful. . . . finally raining on Amelia Island Fla. . . .
Randall Guess -- Thursday, 07/16/98 17:38:29 GMT
Randall, Grandpa is the one to steer you straight on this one, but YES you can do more to
develope the pattern. When making cable or chain Damascus the pattern is created by the
weld interfaces where the surface of the metal has changed in carbon content. This creates
the high and low carbon areas that etch differently. All the standard methods of pattern
development should apply. Twisting and reforging will change the pattern as will twisting
two pieces and welding them together. Cutting or grooving and reforging will probably not
make as dramatic of changes due to the non-linearness of the interfaces.
Predictability is going to be the problem. All those oddly shaped pieces layered together is
mind boggling from the start. Lots of experimentation is the only answer. There may be
someone that has already run these experiments.
Roller chain: Machinery's Handbook, 23rd Ed. has an SAE steel chart that says:
These are nickle chromium and nickle chromium molyebdenum medium hardenability steels.
The roller shells may be case hardened.
As always with unknown alloys it is best to test the hardenability AND especially with an experimental laminated steel.
- Pins 4320, 4815.
-- guru Thursday, 07/16/98 18:28:50 GMT
References and Links
2001 Jock Dempsey, www.anvilfire.com