BS 1580-3:2007

Foreword
1 Scope
2 Normative references
3 Terms and definitions and symbols
4 Thread profiles
5 Diameter/pitch combinations
6 Tolerance classes
7 Tolerances, allowances and limits of size for uncoated threads
8 Coated threads
9 Designation of threads
10 Gauges
Annexes
Annex A (normative) - Unified screw threads below [1/4] in
        diameter for attachment purposes and for general use
        in the aircraft industry
Bibliography

Describes limits of sizes, and tolerances, for single-start, clearance-fit unified screw threads, in inch units with diameters below [1/4] in.

This part of BS1580 specifies limits of sizes, and tolerances, for single-start, clearance-fit unified screw threads, in inch units with diameters below in. This part of BS1580 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 AnnexA.