These replacement blades are meant to be used for the No. 4-1/2, 5-1/2 and 7 of the Busy Bee line of planes. They are made from O1 steel are hardened to 58-62 HRC can also be used in most vintage Stanley-type planes as well. Whether you have used up a blade or want a second blade to sharpen differently, these blades will defiantly fit the bill.
Made from O1 steel that takes a fine edge
Hardened to 58-62 HRC
Blade width: 2-3/8”
Blade thickness: 3mm