5/16" Steel Plate Round Circle Disc 12" Diameter A36 Steel (.3125) Made by Harness Machine & Fab in Indiana Please contact Harness Machine & Fab for other sizes, materials, and custom cuts. We supply angle, flat bar, tubing, channel, and other steel products. We stock aluminum, stainless steel, brass, mild steel, hardened steel, and several other products. We offer CNC High Definition plasma cutting holding tight tolerances CNC Oxyfuel cutting Precision Sawing Bending