CPC Subgroup
B21K 1/54 with grooves or notches
Full Title
Making machine elements > bolts, studs, or the like (making screw-thread B21K1/56; making U-bolts B21K1/74) > with grooves or notches
B21K 1/54 Making machine elements > bolts, studs, or the like (making screw-thread B21K1/56; making U-bolts B21K1/74) > with grooves or notches