1095 Hard Blue Tempered Spring Steel Shim .007" x 6.00" Wide x 50" Long Thickness Tolerance ±0.0004"Width tolerance is ±0.010". Length tolerance is ±1/2". C1095 Blue Tempered and Polished Spring Steel. Rockwell hardness C 50. MIL-S-7947, AISI-1095, SAE- 1095, and AMS-5122.