Whiskers I would say UNC and UNF as those are the most common. All the others are either antique as BSW British Standard Whitworth is or are pipe threads and BA British Association screw threads which are a ra... I would say UNC and UNF as those are the most common. All the others are either antique as BSW British Standard Whitworth is or are pipe threads and BA British Association screw threads which are a rarity these days. Have a read on Wikipedia about the BSW as that thread actually facilitated the world's first mass production by multiple manufacturers simultaneously. Ninety in number sixty horsepower engines for the Royal Navy in 90 days. This was in 1855. Mehr zeigen