BS 1580-3:2007

This standard BS 1580-3:2007 Unified screw threads is classified in these ICS categories:

• 21.040.20 Inch screw threads

This part of BS 1580 specifies limits of sizes, and tolerances, for single-start, clearance-fit unified screw threads, in inch units with diameters below in.

This part of BS 1580 specifies unified screw threads from Number 0 (0.060 in diameter) to Number 12 (0.216 in diameter), known as the “numbered sizes” in the following standard series:

• a coarse thread (UNC) series;

• a fine thread (UNF) series;

• for Number 12 threads, an extra fine (UNEF) 32 threads per inch diameter/pitch combination.

  NOTE Unified screw threads below in diameter for attachment purposes and for general use in the aircraft industry are specified in Annex A.