Writing up metallurgy for a campaign

[Fnugus]

Originally Posted by Polydamas

One problem in a fantasy setting is that alloys of iron and of copper do not have standardized properties: two lumps of "Spanish iron" or "latten" could be quite different in composition.

This is exactly the point. How would one go about writing up the differences between ordinary steel (whatever we call it), very fine steel (Damascus steel, maybe?), pig iron, etc.'? Just having some properly grounded baselines for these differnt types of steel could allow for some extrapolation. It'd be even better if one could add the same things for different types of bronze (cornthian bronze, hepatizon, orichalcum, etc.). Then for each other material, it could be compared to these figures.

Originally Posted by Polydamas

GURPS “DR” measures resistance to penetration not hardness as engineers use the term. The engineering term hardness is only one factor in resistance to penetration.

Indeed. And in engineering that is (AFAIK) a combination of hardness, plasticity, elasticity, etc. (tensile strength, ductile strength, w/e). So this is abstracted down into a single figure, and for brittle or semi-brittle materials, we just define them as ablative or semi-ablative, respectively. Big question is, how would the scale for DR go? A material with double the strength have double DR? Or is it quadratic, cubic, or something else entirely?

Originally Posted by Polydamas

The hit points of a solid sheet of material are determined by its mass according to a formula in the Basic Set (4e).

As with most homogenous objects. This is the easy part.