CPC Subgroup
B24B 19/20 for grinding dies (for grinding walls of very fine holes B24B5/48)
Full Title
Single-purpose machines or devices for particular grinding operations not covered by any other main group (tapering, chamfering, or relief cutting of taps or reamers B24B3/20, B24B3/22, grinding screw threads B23G) > for grinding dies (for grinding walls of very fine holes B24B5/48)