Blade composition Era Carbon (edge) Carbon (body) Manganese Silicon Phosphorus Copper 1940s 1.02% 1.02% 0.37% 0.18% 0.015% 0.21% 1800s 0.62% 1.0% 0.01% 0.07% 0.046% 0.01% 1700s 0.69% 0.43% 0.005% 0.02% 0.075% 0.01% 1500s 0.5% 0.5% 0.005% 0.04% 0.034% 0.01%