system. Its two holes are positioned symmetrically, with the centers apart. Japan In Japan, loose leaf in A4 and JIS B5 sizes (for binders) usually has 30 and 26 holes respectively according to the standard JIS Z 8303 (section 11); which specifies holes of 6±0.5mm of diameter, with their centers every , and a distance of from the center of the holes to the edge of the paper with the additional restriction that the holes must be placed in positions symmetric to the axis across the middle of the page. Swedish triohålning In Sweden, a four-hole national standard is almost exclusively used. The centers of the holes are , and apart, from the edge of the paper. The guides help keep the paper in a straight line. The official name of this four-hole system is triohålning, since it was adapted to the "Trio binder" which was awarded Swedish patent in 1890. The binder's inventor, Andreas Tengwall, supposedly named it after a consortium consisting of himself and two companions, i.e. a trio. The binder can be opened at any place while holding the papers in place, as the inner holes have guide pins from one side, the outer holes have pins from the other side. Others The Filofax system uses six holes in two groups of three Hole spacing chart Gallery See also Ticket punch Needle punch Chad (paper) Paper drilling Ring binder Punched card Punched tape Punching References External links Office equipment Hole making German inventions 19th-century inventions ISO standards