72 / | HD | METAL DEFORMING |
199 | DF | BY USE OF ROLLER OR ROLLER-LIKE TOOL-ELEMENT {17} |
226 | DF | .~ Plural roller-couples (e.g., successively or optionally usable) {3} |
232 | .~.~ Including one roller common to two roller-couples (e.g., three-high mill) {1} | |
233 | DF | .~.~.~> Including roller shiftable between successive passes of work |