yes, it is made of aluminum. 6061 as I recall. I would like to have it hard anodised some time, but it works great as it is for the small projects I do.
Interesting. Of course, a 'real' toolmaker's vise 'should' be made from hardened steel, shouldn't it, but I wonder how many people are getting quite satisfactory results from aluminium alloy? Seems I have seen a fair bit of tooling (even commercial stuff) made from Aluminium, and I am wondering...
Fwiiw, I have even made up an ER35 chuck (just the female holder bit) to mount flat on a mill table out of nylon 66. Plastic?!?!? For light milling of Al & brass it seems quite stable.
Cheers