DIN Standards Committee Technical Fundamentals
DIN 68101
Fundamental deviations and tolerance zones for wood working and wood processing
Grundabmaße und Toleranzfelder für Holzbe- und -verarbeitung
Overview
This standard specifies fundamental deviations and tolerance zones, which can be used for parts to be paired. The fundamental deviations and tolerance zones in accordance with this standard are applicable for length dimensions for wood and wood-based panels at an agreed moisture content. Dimensional modifications due to swelling and shrinkage shall be taken into account (see DIN 68100). The provided tolerance zones can be optionally paired with fits. In order to keep operating expenses for test equipment and tools to a minimum it is, however, recommended not to exhaust the number of possible fits and to use, if possible, only standardized interior dimensions or only standardized exterior dimensions. With respect to DIN 68101:1984-12, the tolerance zone principles have been adapted to DIN EN ISO 286 in order to simplify the tolerance rules, or fit layout, and to enable, if applicable, the intuitive selection of tolerance zones in daily practice. Fits between tolerances in accordance with this, and other, standards (for instance, for components made of metal, plastics, glass) are thus interpretable without issue. In DIN 68101:1984-12 the tolerance zone positions (fundamental deviations) have still been defined by a multiplier with the selected standard tolerance. With the new edition, these values result depending on the nominal dimensional ranges as minimal clearances exclusively with the standardized tolerance HT 15. The tolerance zone positions (a/A through z/Z) are decoupled from the tolerance zone widths (HT 1 through HT 400), which can be freely selected in accordance with DIN 68100. Tolerances around the nominal dimension (zero line) can be selected symmetrically in accordance with DIN 68100 or according to this standard by the tolerance zone position m/M with a one-sided fixed fundamental deviation. With regard to the designation, the specification "interior dimension" or "exterior dimension" has been waived as this is clearly represented by use of capital or lowercase letters. The committee responsible for this standard is NA 042-04-03 AA "Toleranzen und Zeichnungen" ("Tolerances and drawings") at DIN.
