I have to guess a lot for shields.
I guess the system uses their chance to block as a percentage the same way the rest of the armor uses coverage and layer size. And I guess that they are destined for arms even though dwarfs are usually seen just carrying them in their hands. Using the hand % of the body plan gives very low numbers that don't sound right. But UristDaVinci didn't post a percentage for arms, and I don't quite understand how he got his numbers. So working backwards from his %s and the body data in the raws I would guess that arms are 7.35% or .0735 in the spreadsheet.
items | STEP_FACTOR | COVERAGE | LAYER_SIZE | BASE_SIZE | VOLUME | iron/steel | bronze | copper | leather/bone/shell | | similar part weight ratios |
shield | 1.5 | 20 | 100 | 661.5 | 132.3 | 10.39 | 10.91 | 11.81 | 0.66 | | 2.4 |
buckler | 1.25 | 10 | 100 | 551.25 | 55.125 | 4.33 | 4.55 | 4.92 | 0.28 | | 0.416666666666667 |
This gives me results that at least look close to possible. The wiki says that copper shields can weigh 13 urists and I'm getting just under 12. If the % of the body part is closer to .08 (maybe it includes the hand and the arm? maybe i'm wrong about how to get the %?) then I get a copper shield just under 13 urists.
items | STEP_FACTOR | COVERAGE | LAYER_SIZE | BASE_SIZE | VOLUME | iron/steel | bronze | copper | leather/bone/shell | | similar part weight ratios |
shield | 1.5 | 20 | 100 | 720 | 144 | 11.30 | 11.88 | 12.86 | 0.72 | | 2.4 |
buckler | 1.25 | 10 | 100 | 600 | 60 | 4.71 | 4.95 | 5.36 | 0.30 | | 0.416666666666667 |
The weight ratio stays the same either way, but it's still a bunch of guesses.