... 3. Size: 1/8" to 7/8" 4. Hardness: 58-62HRC We've been concentrated on manufacturing CUSTOMER ... is HRC55-60, for dia100-150mm is HRC50-60.Core hardness for dia25-90mm is HRC40-50,for dia100-150mm ... 0.2-0.4, Cr: 0.25MAX.Speciality:High hardness,no breakage,good wear resistance,even wearing.Applied field: ... is HRC55-63, for dia100-150mm is HRC55-63.Core hardness for dia25-90mm is HRC48-55,for dia100-150mm ...