Perforation
The term perforation has different meanings:
- Perforation, a technique used in forging to expand or punch out metal, usually iron / steel for connecting rods, e.g. B. for grids
- Perforation of postage stamps, see Perforation (Philately)
- Punching documents using a text perforating machine, e.g. B. the forgery-proof date of receipt of an application at the patent office
- Perforation of sheets or cross members to reduce weight, see perforated sheet
- Perforation for filing papers in files, loose-leaf binders or loose-leaf collections, dimensions according to DIN ISO 838 see Punch # International standards and punching systems
- Perforation for validating tickets or admission tickets, see validator
- Perforation of a mechanical storage medium for data, see punch card