Without Center PunchWithout Center Punch - NotchedPlain Harrow Disc BladesHarrow Disc Blades - Notched

High Carbon Steel American Standard SAE 1070 & nearly equivalent to EU Standard EN42
Hardness: 38 – 42 HRC

Boron Steel: 30MnB5, 32MnB5
Hardness: 48 – 52 HRC