Mystery shim identification?

[hillsy]

Those drilled shims should go straight onto a keyring

[fbody_mike]

Maybe a machinist can chime it, but wouldn't those holes have had to be drilled before the shims are hardened? From what my experience the shims are brittle like glass and I would think it would take a lot to drill them, but I have never tried.

[storm 64]

Maybe a machinist can chime it, but wouldn't those holes have had to be drilled before the shims are hardened? From what my experience the shims are brittle like glass and I would think it would take a lot to drill them, but I have never tried.

Not necessarily, a EDM (Electrical Discharge Machine) could make a hole in the hardest of steel. It uses a graphite electrode to "burn" a hole through it. The EDM is a very popular machine in the extrusion die business.
Also the EDM machines go back to the 60's. So Pops could have very well used it��

[GregT]

Not necessarily, a EDM (Electrical Discharge Machine) could make a hole in the hardest of steel. It uses a graphite electrode to "burn" a hole through it. The EDM is a very popular machine in the extrusion die business.
Also the EDM machines go back to the 60's. So Pops could have very well used it��

Yeah, an EDM will do it - but a carbide drill would probably also do it. Guy here was using carbide drills to put holes in bearing races for locating pins.
I've used carbide tips to machine hardened shafts too. Late 5 speed box into an early 4 speed Aermacchi (HD Sprint) needs the layshaft ends machined to suit the 4 sp bearing sizes...
Lightening the buckets is a bit trickier. They are hardened right through and the skirts (sides) are brittle. To do them I'd think you'd either get them unhardened from Suzuki (or their supplier) or soften, drill and reharden.
Wouldn't surprise me if Pops got the idea from Jaguar race stuff. The yanks were drilling holes in everything in a Jag engine in the '60's - but those buckets are chilled cast iron so a bit nicer to work with....