B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
B21D51/00—Making hollow objects
B21D51/16—Making hollow objects characterised by the use of the objects
B21D51/38—Making inlet or outlet arrangements of cans, tins, baths, bottles, or other vessels; Making can ends; Making closures
B21D51/383—Making inlet or outlet arrangements of cans, tins, baths, bottles, or other vessels; Making can ends; Making closures scoring lines, tear strips or pulling tabs
G—PHYSICS
G11—INFORMATION STORAGE
G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
G11B3/00—Recording by mechanical cutting, deforming or pressing, e.g. of grooves or pits; Reproducing by mechanical sensing; Record carriers therefor