I'll let zagibu's hard work show what I've been unable to convey.
Test method: 10 rounds of 1 vs 1.
Race: modded dwarf (average stats, removed intelligence tag, added noexert tag).
Equipment: attacker has full adamantine armor + weapon to be tested and vitim has full armor to be tested + wooden sword.
Displayed: hit ratio (green), light wounds (yellow), medium wounds (orange), heavy wounds (red)
| silver armor | copper armor | iron armor | bronze armor | steel armor | adamantine armor |
| silver hammer | 21% 66% 31% 3% | 20% 58% 41% 1% | 17% 69% 30% 1% | 14% 68% 31% 1% | 18% 61% 37% 2% | 5% 82% 18% 0% |
| copper hammer | 17% 66% 32% 2% | 17% 65% 32% 3% | 15% 65% 33% 2% | 16% 60% 39% 1% | 15% 71% 28% 1% | 4% 95% 4% 1% |
| iron hammer | 17% 69% 29% 2% | 11% 76% 22% 2% | 13% 73% 25% 2% | 13% 67% 31% 2% | 13% 70% 28% 2% | 4% 95% 5% 0% |
| bronze hammer | 19% 67% 31% 2% | 16% 66% 32% 2% | 14% 70% 29% 1% | 12% 76% 22% 2% | 13% 74% 25% 1% | 4% 90% 8% 2% |
| steel hammer | 17% 71% 28% 1% | 14% 65% 35% 0% | 13% 71% 28% 1% | 12% 74% 25% 1% | 13% 68% 31% 1% | 3% 94% 5% 1% |
| adamantine hammer | 1% 99% 0% 1% | 1% 100% 0% 0% | 1% 99% 0% 1% | 1% 99% 0% 1% | 1% 100% 0% 0% | 1% 98% 0% 2% |
| silver armor | copper armor | iron armor | bronze armor | steel armor | adamantine armor |
| silver mace | 18% 73% 25% 2% | 16% 76% 22% 2% | 13% 75% 23% 2% | 12% 82% 16% 2% | 15% 72% 26% 2% | 6% 83% 16% 1% |
| copper mace | 14% 84% 14% 2% | 12% 75% 22% 3% | 13% 73% 25% 2% | 11% 77% 22% 1% | 12% 79% 19% 2% | 5% 83% 16% 1% |
| iron mace | 16% 76% 23% 1% | 12% 80% 19% 1% | 11% 83% 15% 2% | 10% 78% 20% 2% | 12% 76% 23% 1% | 4% 83% 16% 1% |
| bronze mace | 17% 70% 29% 1% | 12% 83% 15% 2% | 12% 77% 22% 1% | 12% 74% 25% 1% | 11% 81% 18% 1% | 6% 79% 20% 1% |
| steel mace | 15% 81% 18% 1% | 12% 76% 23% 1% | 11% 78% 19% 3% | 10% 85% 14% 1% | 11% 82% 16% 2% | 4% 85% 14% 1% |
| adamantine mace | 1% 99% 0% 1% | 1% 99% 0% 1% | 1% 97% 0% 3% | 1% 100% 0% 0% | 1% 99% 0% 1% | 1% 100% 0% 0% |
| silver armor | copper armor | iron armor | bronze armor | steel armor | adamantine armor |
| silver spear | 13% 67% 31% 2% | 10% 65% 33% 2% | 8% 72% 26% 2% | 8% 73% 25% 2% | 8% 70% 29% 1% | 2% 74% 25% 1% |
| copper spear | 8% 78% 21% 1% | 8% 75% 24% 1% | 7% 85% 14% 1% | 7% 86% 13% 1% | 7% 78% 20% 2% | 2% 74% 22% 4% |
| iron spear | 98% 0% 94% 6% | 9% 63% 34% 3% | 8% 72% 26% 2% | 6% 83% 14% 3% | 6% 86% 13% 1% | 1% 77% 21% 2% |
| bronze spear | 99% 0% 100% 0% | 98% 0% 100% 0% | 99% 0% 100% 0% | 7% 74% 25% 1% | 6% 85% 13% 2% | 2% 68% 32% 0% |
| steel spear | 99% 0% 90% 10% | 99% 0% 100% 0% | 99% 0% 100% 0% | 99% 0% 100% 0% | 8% 76% 23% 1% | 2% 71% 27% 2% |
| adamantine spear | 99% 1% 99% 0% | 99% 0% 100% 0% | 99% 0% 100% 0% | 99% 0% 100% 0% | 99% 0% 100% 0% | 1% 71% 26% 3% |
| silver armor | copper armor | iron armor | bronze armor | steel armor | adamantine armor |
| silver sword | 3% 59% 23% 18% | 9% 74% 17% 9% | 3% 65% 19% 16% | 3% 70% 17% 13% | 3% 55% 27% 18% | 1% 32% 46% 22% |
| copper sword | 3% 65% 25% 10% | 3% 66% 26% 8% | 3% 66% 19% 15% | 3% 55% 31% 14% | 2% 52% 40% 8% | 1% 36% 48% 16% |
| iron sword | 98% 0% 11% 89% | 9% 79% 2% 19% | 2% 62% 3% 35% | 2% 52% 4% 44% | 2% 60% 7% 33% | 1% 45% 14% 41% |
| bronze sword | 98% 0% 17% 83% | 100% 0% 20% 80% | 99% 0% 6% 94% | 2% 65% 2% 33% | 2% 53% 6% 41% | 2% 48% 8% 44% |
| steel sword | 98% 0% 3% 97% | 100% 0% 10% 90% | 98% 4% 15% 81% | 100% 0% 2% 98% | 2% 50% 3% 47% | 1% 43% 5% 52% |
| adamantine sword | 98% 0% 16% 84% | 100% 0% 31% 69% | 98% 0% 8% 92% | 99% 0% 21% 79% | 100% 0% 5% 95% | 1% 34% 3% 63% |
| silver armor | copper armor | iron armor | bronze armor | steel armor | adamantine armor |
| silver axe | 7% 60% 0% 40% | 14% 18% 43% 39% | 5% 51% 11% 38% | 4% 50% 2% 48% | 6% 69% 1% 30% | 1% 10% 0% 90% |
| copper axe | 5% 58% 6% 36% | 4% 63% 0% 37% | 4% 50% 2% 48% | 4% 44% 0% 56% | 4% 62% 3% 35% | 1% 11% 2% 87% |
| iron axe | 94% 0% 3% 97% | 9% 28% 36% 36% | 4% 46% 3% 51% | 3% 50% 0% 50% | 3% 42% 0% 58% | 1% 19% 0% 81% |
| bronze axe | 100% 0% 0% 100% | 100% 0% 6% 94% | 91% 0% 0% 100% | 3% 48% 1% 51% | 4% 58% 2% 40% | 2% 13% 0% 87% |
| steel axe | 97% 0% 8% 92% | 100% 0% 0% 100% | 97% 0% 0% 100% | 96% 0% 0% 100% | 4% 53% 4% 43% | 1% 6% 0% 94% |
| adamantine axe | 98% 0% 2% 98% | 100% 0% 0% 100% | 93% 15% 0% 85% | 100% 0% 0% 100% | 97% 0% 0% 100% | 2% 10% 0% 90% |
I'd say the issue is more that Iron weapons suck than that iron armor is good. However, since iron weapons do suck, iron armor is quite serviceable.