Screwing taps — Part 1: Specification of general dimensions

2Scope / Description

1.1 This Part of this British Standard specifies the
general dimensions and tolerances for screwing taps
for the following threads:
a) ISO metric coarse pitch series threads
complying with BS 3643;
b) ISO metric fine pitch series threads complying
with BS 3643;
c) Unified (ISO inch) general-purpose screw
threads, coarse thread series (UNC), from No. 1
to No. 12 and from in to 4 in diameter
complying with BS 1580-1, BS 1580-2 and
BS 1580-3;
d) Unified (ISO inch) general-purpose screw
threads, fine thread series (UNF), from No. 0 to
No. 12 and from in to 1 in diameter complying
with BS 1580-1, BS 1580-2 and BS 1580-3;
e) British Standard Whitworth (BSW) threads
from A in to 4 in diameter and British Standard
Fine (BSF) threads from in to 3 in diameter
complying with BS 84;
f) British Association (BA) threads from No. 14 to
No. 0 complying with BS 93.
1.2 The sizes of taps specified include those suitable
for the tapped holes for sparkings plugs and those
suitable for the tapped holes for fittings for steel
conduit specified in BS 4568.
NOTE The titles of the publications referred to in this standard
are listed on the inside back cover.