Screws were described as "2BA", "4BA" etc. 2BA threads are commonly found in the old imperial BESA conduit boxes. BA sizes were also used extensively in aircraft, especially those manufactured in the United Kingdom.
2BA Slotted Machine Screws BZP (CSK/R/CSK/CHEESE HEAD/ROUND HEAD/MUSHROOM HEAD)
0BA 2BA 4BA 5BA 6BA 8BA Nylon Cheesehead Slotted Plastic Bolts / Screws
2BA 1BA 0BA 3BA 4BA Cheesehead Flat Slotted Machine Screws Bolts BZP
Vintage 2BA Slotted Hex Nut x 5
SOLID BRASS SLOTTED COUNTERSUNK WOOD SCREWS ALL GAUGES & SIZES 2,3,4,6,8,10,12
No4 No6 No8 No10,12,14 Stainless Raised Countersunk Slotted Self Tapping Screws
