2BA or not 2BA? That is the question

BA SPANNER AND SOCKET SET £44.21

BA (British Association) screw thread sizes cover a range of small screw threads that can be found on classics right up to the early 1970s, on such things as speaker enclosures and instrument panels. This useful set from Laser Tools will tackle them and includes 11»-drive sockets made from chrome vanadium steel: OBA, 1BA, 2BA, 3BA, 4BA, 5BA, 6BA, 7BA, 8BA, 9BA and 10BA. The six open-ended spanners are sized at 0BA x 2BA, 1BA x 3BA, 4BA x 6BA, 5BA x 7BA, 8BA x 10BA and 9BA x 11BA. Part number 7132. lasertools.co.uk