Search results
Results from the WOW.Com Content Network
British Standard Fine (BSF) is a screw thread form, as a fine-pitch alternative to British Standard Whitworth (BSW) thread. It was used for steel bolts and nuts on and in much of Britain's machinery, including cars, prior to adoption of Unified , and later Metric , standards.
The Thury thread form had the crests rounded at 1 / 6 p and the roots rounded at 1 / 5 p so the thread angle was close to 47.5° but not exactly. This was simplified in the BA thread definition by defining the thread angle to be 47.5° exactly and the thread form to be symmetrical with a depth of 3 / 5 p.
British Standard Whitworth (BSW) is an imperial-unit-based screw thread standard, devised and specified by Joseph Whitworth in 1841 and later adopted as a British Standard. It was the world's first national screw thread standard, and is the basis for many other standards, such as BSF, BSP, BSCon, and BSCopper.
For premium support please call: 800-290-4726 more ways to reach us
Unlike other major British imperial thread standards (British Standard Whitworth and British Standard Fine) the thread runs at a 60 degrees rather than a 55 degrees angle. All sizes 1 ⁄ 4 inch and larger use 26 threads per inch (tpi), making them similar to 1 mm ISO threads , which are 25.4 per inch and also run at a 60 degrees angle.
Hard bolívar, abbreviated BsF or Bs.F, the currency of Venezuela from 2008 to 2018; Boysetsfire, an American post-hardcore rock band; Bradshaw Army Airfield, with IATA airport code BSF; British Standard Fine, an imperial-unit based screw-thread standard; Building Schools for the Future, a British Government initiative to rebuild schools, from ...
If the thread does not use the normal coarse pitch (e.g. 1.25 mm in the case of M8), then the pitch in millimeters is also appended with a multiplication sign (e.g. "M8×1" if the screw thread has an outer diameter of 8 mm and advances by 1 mm per 360° rotation). The nominal diameter of a metric screw is the outer diameter of the thread.
The greatest disadvantage is the difficulty in machining such a thread. The single-point cutting tools or taps and dies used to cut the thread cannot have efficient rake and relief angles (because of the square form), which makes the cutting slow and difficult. Square threads also cannot carry as much load as a trapezoidal thread, because the ...