DIN 21320:1987-06

These quality specifications and terms of delivery apply mainly to props, canopies and half-round pieces of timber as per DIN 21316, for bars and split bars as per DIN 21317, and for struts as per DIN 21319, made from leaf or pinewood and used in mining; in their original round shape, cut over their length once or several times, squared, with or without their bark. Squared timber is round timber sawn over the whole length, the width of the cut surface being approximately equal to half the diameter of the round timber.