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pntrbl
07-03-2009, 02:03 AM
Just for educational reasons I started looking at the stock swing arm bushing out of a Hodaka. My brother is still on the Delrin kick as a substitute and we're looking for more ammo for the debate. :D

The stock Hodaka bushing is a grey material. Magnetic. And fairly hard. I don't know the Rockwell from a Rock Wall, lol, but it's stout enough to deform conventional oil impregged bronze. By offsetting pieces of roughly the same dia and wall thickness in my bench vise I can get a good dent in the bronze without bothering the Hodaka bushing at all.

Tried some mild steel too and again the Hodaka part reigned supreme.

It does not pass the file test tho so I don't believe we've got a hardened part here. But it ain't exactly soft.

Cast Iron occurred to me so I chucked it up and had a cut. It crumbles. I think it's Cast Iron. Or at least a CI alloy of some kind. If it walks like a duck ....

I personally have never heard of cast iron being used as a bushing, but that doesn't count for much! Whaddayu guys think? Could it be?

SP

Rustybolt
07-03-2009, 11:07 AM
It could be sintered steel. How hard is the shaft?

lazlo
07-03-2009, 11:22 AM
I personally have never heard of cast iron being used as a bushing, but that doesn't count for much! Whaddayu guys think?

Grey cast iron makes great bushings -- the graphite in the iron makes it self lubricating.

If the cast iron is hardened, I'd imagine the swing-arm pin is hardened steel?

Swarf&Sparks
07-03-2009, 11:29 AM
Shee!t, is that the old Hodaka dirt squirt?

Yeah, I've seen many a cast iron bushing/bearing.
Usually in slow revving, heavy loaded situations, which sounds like a swingarm :D

Optics Curmudgeon
07-03-2009, 06:03 PM
Rustybolt's real close, I'd say it's Super Oilite, an extra heavy duty version of the normal bronze Oilite, but using iron powder instead of bronze. It's a sintered iron / graphite mix, oil soaked. Popular in small motors and slide bearings in printers, etc.

Joe

pntrbl
07-03-2009, 08:49 PM
Sintered Steel? Hmm. Learn something everyday.

And yeah, I need a look at the shaft the bushings support.

Thanx again guys. The search is on .....

SP

luthor
07-03-2009, 08:58 PM
More likely sintered iron as mentioned above, not sintered steel.

tattoomike68
07-03-2009, 09:31 PM
Aluminum/ nickle bronze is hard stuff, it would work as a replacment for sure.

Rustybolt
07-03-2009, 10:17 PM
You're right, iron. We get em on the motors of the cheap pumps we use at work. They shouldnwork well in your low rpm high load application like a swing arm. judt keep em greased.