i suggest layers and layers of cardboard
for rc works
309
duev to its ductility
mild steel.
Zinc
mild steel
Because hard steel would be brittle and break.
During a tensile test of mild steel, the bar is tested until it breaks. It measures how much stress the mild steel can take before it finally breaks under the pressure.
both of these are same In some places they are used interchangeabl low carbon steel has 0.05-0.15% carbon mild carbon steel has0.16-0.29% carbon http://www.metalsupplies.com/
1)mild steel 2)ripped torsion steel 3)nical alloy steel 4)deformed steel
tensile test
mild steel