Pittsburg Safe Co

[Huw Eastwood]

I was surprised that the cast iron was so hard.

Cast and chilled irons are notorious for it tbh- if it doesn't get you with a hard outer 'skin' then internal hard spots often will- and they'll decimate HSS tooling. Carbide drills, slot and end mills or the indexable lathe bits if turning, combined with very slow speeds generally get around the problem. I've had some stubs of cast bar in the past that've had hard spots so tough you'd think it was Stellite.

But, it's not always that bad- I recently turned a large spoked flywheel the extreme maximum diameter my lathe will take (it cleared the bed by about 2mm !) and, but for black graphite dust everywhere and a coal miners face it actually turned beautifully.