Swing Bolts DIN 444, form B steel 8.8 tempered black M8 / 40 / 8

The number before the point multiplied by one hundred gives the nominal value of the tensile strength in N/mm2, the number before the point multiplied by the number after the point and multiplied by 10 gives the nominal value of the 0.2% yield strength in N/mm2. The number after the decimal point provides information about the yield strength, as a percentage of the tensile strength.

Tempered steel is steel that is given high tensile and fatigue strength through tempering. The toughness is determined by the relationship between hardness and temperature of the subsequent tempering process. It is a transformation hardening in which the ratio of strength to toughness is specifically influenced.