Air Hard Flat Stock, Material Steel, Width 1", Thickness 1/4", Finish RMS 45 Max, Length 18", Length Tolerance .125"/.250", Hardness Scale 200 to 235 BHN, Grade A2, Standards UNS T30102, SAE J-437, ASTM A-681-07, FEDERAL QQT-570 REV CSpecification:Length - 18" Length Tolerance - +.125"/.250" Hardness Scale - 200 to 235 BHN Grade - A2 Standards - UNS T30102, SAE J-437, ASTM A-681-07, FEDERAL QQT-570 REV C WARNING::California ResidentsThis product can expose you to chemicals including Styrene, which is known to the State of California to cause cancer and birth defects or other reproductive harm.