PURPOSE: To continuously manufacture cutting edge supporting springs with excellent yield of a metallic plate, by forming a clearance groove first, and then, a shearing section following the groove, when numerous cutting edge supporting springs are manufactured by blanking and bending a beltlike metallic plate.

CONSTITUTION: A beltlike metallic plate A having pilot holes 8 is fed rightward by steps and clearance grooves 3 and 4 are formed at one margin of the plate A by blanking. Then, a shearing section 5 following the clearance groove 4 is formed by shearing, and a projected piece 2 sectioned by the clearance grooves 3 and 4 and the shearing section 5 is bent. To bend the projected piece 2, the end of the piece 2 is bent first, and then a step 6 are formed at the central part by bending. When the steps 6 are made, the bending line B is obliquely set at an angle α so that the width of the groove 3 becomes wider as it go to the end of the projected piece 2. Finally, the base parts of a pair of projected pieces 2 are bent so that a pair of cutting edge supporting pieces 1 and 1 will be formed.