... and hardness, more durable.2.one brake.3.Material of blade is 50# carbon steel, 0.1mm thickness.(It depends on ... elastic,65# manganese steel material,toughness is very good.5.Blade Graduations:metric Graduation,British-metric Graduation,british Graduation. size and ... /25ft×25mm9632/3138×27×3610m/33ft×25mm8034/3342×20×38. high quality steel measuring tape