Apart from 1/2″ diameter BSW and UNC threads are compatible. BSW, also known as Whitworth, is a British thread standard devised in the 19th century. UNC or unified course thread is an American thread standard and is very widely used. Examples: For example, 1/4BSW and 1/4UNC threaded fasteners are interchangeable, as are 5/16BSW and 5/16UNC threaded fasteners. A 1/4BSW nut fits a 1/4UNC bolt and 1/4UNC nut fits a 1/4BSW bolt. The sizes that we get asked about the most and which cause the most confusion are 3/16BSW and 10-24UNC. The UNC standard uses gauge sizes to denote diameters of less than 1/4 in diameter. No, we dont know why either! 10-24UNC is one of these sizes. A 10-24UNC fastener has a diameter of 10 gauge and has 24 threads per inch. The good news is 10-24 is exactly equivalent to 3/16 BSW. They are interchangeable. Its worth repeating and underlining: 3/16BSW and 10-24UNC threads are equivalent and interchangeable. Note a couple of things. [1] 1/2BSW and 1/2UNC are not equiv
BSW and UNC threads are compatible except for 1/2″ diameter. BSW, also known as Whitworth, is a British thread standard devised in the 19th century. UNC or unified course thread is an American thread standard and is very widely used. Examples: 1/4BSW and 1/4UNC threaded fasteners are interchangeable, as are 5/16BSW and 5/16UNC threaded fasteners. A 1/4BSW nut fits a 1/4UNC bolt and 1/4UNC nut fits a 1/4BSW bolt. The sizes that we get asked about the most and which cause the most confusion are 3/16BSW and 10-24UNC. The UNC standard uses gauge sizes to denote diameters of less than 1/4″ in diameter. 10-24UNC is one of these sizes. A 10-24UNC fastener has a diameter of 10 gauge and has 24 threads per inch. The good news is 3/16BSW and 10-24UNC threads are equivalent and interchangeable. Note a couple of things. [1] 1/2BSW and 1/2UNC are not equivalent and are not interchangeable. You must match 1/2UNC nuts with 1/2UNC bolts and screws. Similarly 1/2BSW nuts must be matched with 1/2BSW bol