BA threads are used for sizes under 1/8 inch the older British fastener system.

You'll find lots of BA threads on any British car, but only for fasteners smaller than 1/4". BA fasteners have their own set of spanner sizes. Typically, a set of "Whitworth" sockets will include a OBA (and maybe a 2BA--bigger number = smaller size) socket.

BA size chart, for BA nuts and bolts. Skip to primary navigation; Skip to main content; Skip to footer; Macc Models ... Over Thread: Threads per inch: Pitch: Diameter at Thread Bottom: Tapping Drill Size: BUY Taps and Dies: 16 BA: 0.0310 inch: 133.3 tpi: 0.0075 inch : 0.0220 inch: Number drill 73 0.6 mm

2013年2月12日 · British Association Standard Screw Threads are used mainly for instruments and clocks. The BA-series screw threads should not be used for new designs. Instead use the M-series screw threads.

British Association screw threads known as BA screw threads, are a type of small screw thread that is practically obsolete. The largest is 0BA, which has a diameter of 6 mm. They were used for miniature instruments and modeling.

British Association (BA) Screw Threads h -1.13634P r=O.18083P s=o.26817P 47.50' 23.750 D=Major Ø Internal Thread DI —Minor Internal Thread D2=Pitch Ø Internal Thread d2, D2 23.750 dl, DI d=Major Ø External Thread dl=Minor External Thread d2=Pitch Ø External Thread

BRITISH ASSOCIATION (BA) THREADS Angle of Thread is 47.5 degrees ALL DIMENSIONS ARE IN INCHES (EXCEPT TAPPING DRILL) Threads Number Diameter Pitch per Inch Root Diameter Tapping Drill (mm) 16BA 0.031 0.0075 133.3 0.022 0.6 15BA 0.035 0.0083 120.5 0.025 0.7 14BA 0.039 0.0091 109.9 0.028 0.8 ...

BA sizes range from 16BA (smallest) and 0BA the largest. Look below for a full chart of dimensions and measurements. If you are still unsure either email details or send in a sample for checking. Hex Set Screws Nuts - Chamfered on one side only

For most threads there is a choice of drill sizes. Smaller size drills will produce threads closer to the full thread form, larger drills will produce threads with less than the full thread form. The percentage of full thread form is indicated for each drill size (see below).

Home » Technical Pages » Thread Identification Chart » Thread Identification Chart (British) Thread Identification Chart (British) Basic Major Diameter. Nominal Diameter (mm) Threads Per Inch; Inch mm BA BSW BSF BSP BSPT.0118: 0.30 ... BA-British Association BSW-British Standard Whitworth BSF-British Standard Fine BSP-British Standard Pipe ...