ASTM A36 Mild/Low Carbon Steel Introduction ASTM A36 is the most commonly used mild and hot-rolled steel. It has excellent welding properties and is suitable for grinding, punching, tapping, drilling and machining processes. Yield strength of ASTM A36 is less than that of cold roll C1018, thus enabling ASTM A36 to bend more readily than C1018. Normally, larger diameters in ASTM A36 are not produced since C1018 hot roll rounds are used. ASTM A36 is usually available in the following forms: Rectangle bar Square bar Circular rod Steel shapes such as channels, angles, H-beams and I-beams. Chemical Composition Element Content Carbon, C 0.25 - 0.290 % Copper, Cu 0.20 % Iron, Fe 98.0 % Manganese, Mn 1.03 % Phosphorous, P  0.040 % Silicon, Si 0.280 % Sulfur, S  0.050 % Physical Properties Physical Properties Metric Imperial Density 7.85 g/cm3 0.284 lb/in3 Mechanical Properties Mechanical Properties Metric Imperial Tensile Strength, Ultimate 400 - 550 MPa 58000 - 79800 psi Tensile Strength, Yield 250 MPa 36300 psi Elongation at Break (in 200 mm) 20.0 % 20.0 % Elongation at Break (in 50 mm) 23.0 % 23.0 % Modulus of Elasticity 200 GPa 29000 ksi Bulk Modulus (typical for steel) 140 GPa 20300 ksi Poissons Ratio 0.260 0.260 Shear Modulus 79.3 GPa 11500 ksi Machining The machinability rate of ASTM A36 is estimated to be 72%, and the average surface cutting feed of ASTM A36 is 120 ft/min. Machining of ASTM A36 steel is not as easy as that of AISI 1018 steel. Welding ASTM A36 steel is easy to weld using any type of welding methods, and the welds and joints so formed are of excellent quality. Heat Treatment Any standard carburizing and hardening methods of AISI 1018 steel is suitable for ASTM A36. ASTM A36 is subjected to the following processes: Normalizing at 899°C – 954°C (1650°F-1750°F) Annealing at 843°C – 871°C(1550°F-1600°F) Stress relieving at 677°C – 927°C(1250°F-1700°F) Carburizing at 899°C – 927°C (1650°F-1700°F) Hardening at 788°C – 816°C(1450°F-1500°F) Applications ASTM A36 steel has the following applications: It is used in bolted, riveted or welded construction of bridges, buildings and oil rigs. It is used in forming tanks, bins, bearing plates, fixtures, rings, templates, jigs, sprockets, cams, gears, base plates, forgings, ornamental works, stakes, brackets, automotive and agricultural equipment, frames, machinery parts. It is used for various parts obtained by flame cutting such as in parking garages, walkways, boat landing ramps and trenches.