[Icelander]

Originally Posted by safisher

I'd cut it with a plasma cutter. Assuming it's steel, you anneal it first in the forge, which will soften it. I suspect you'd need a large hydraulic hammer or a hydraulic press to shape it. Hardening back from annealing can be done with a cutting torch (small pieces heated until non-magnetic, then quench) or a large coal forge (make it crudely from concrete blocks and leaf blower). BUT, this may not get it back to full hardness. I would probably just avoid the forging and just cut it with plasma and the cold press it into shape. Or at least, experiment with that first.

Ok, so we've pretty much decided that forging will not be compatible with the extremely high DR per weight for the high hardness, abrasion resistant steel alloys.

Cutting, cold pressing or just accepting that the ultra-hard steels come in flat sheets or gently curving ones and that isn't going to change very much unless you effectively ruin the things that give it higher DR per weight than steels more generally used for shaped armour.

What's your view on AR500 or similar very high hardness, abrasion resistant steel alloys, as regards DR? Should they have the same, extremely high DR for their weight against all damage types or would they resist some types, like piercing, better by about 20% to 50%?

Because I can find what kind of rounds it is rated proof against as ballistic armour and how much such a plate weighs, which gives a fairly good way to estimate DR/Weight, but if we give it that DR across the board, it outperforms late TL8 triple-hardened and nano-crystalline steels, at a cheaper price.

I don't want to do that unless TL8 very hard steels are truly so much more effective than TL6 'Hard Steel' and actually perform better against all threats than the the equivalent weight of the best cutting-edge steel alloys used in vehicular armour in recent years (but nevertheless somehow aren't used for most military armour applications, maybe because they are very hard to shape and work with).

Originally Posted by safisher

A plasma cutter is a common shop tool, the hydraulic hammer costs $5k and up. You can build a junkyard version for very little, though. Heavy presses can be quite expensive.

Plasma cutter would be useful in making improvised APCs out of trucks and tractors too, right?

What about a hydraulic hammer or a heavier press? Do you need them when making armour plates to weld to a truck to make it proof against all smallarm fire up to .50 BMG?

Originally Posted by safisher

If they have a plasma cutter and a hydraulic hammer, yes. You could chop the armor plate up with an angle grinder but it would take a long time and many discs, I suspect. The thing is, a lot of the smaller armor pieces will probably not work as AR500 pieces. Too many sharp curves and bends. You may have to use it only where the shaping is minimal and use high-quality steel in other areas where you need to have a lot

That sounds credible.

What kind of steel, or steel alloy, is high-quality in the 2010s for vehicular armour purposes, but still shapable into personal armour?

And how much of an improvement is it over the fairly mild RHA steel used as the benchmark in GURPS?

As far as DR per thickness and by weight are concerned?

Originally Posted by safisher

Should be possible, with enough time and equipment bonuses.

If $5,000+ in tools like plasma cutters and hydraulic presses are what you need to be able to do the work at all, how expensive are the tools you need for +1, +2 or an even higher bonus?