bsf taps

[larry53]

I was looking for a bsf tap and the only one I could find is a ns tap. The size I am looking for is a 3/8 20 bsf but on msc web page the only thing list is a 3/8 20 ns tap. Is this the same thread?

[djr76]

call msc, they will have an answer...Ive looked on the internet and its kinda hard to interpret the info since there are some minor interchangeability issues, it might work but not 100% sure. http://www.ring-plug-thread-gages.com/ti-N-vs-UN.htm read this and look in this site. Maybe a tap or threading expert here can give a clearer explanation.

[mrainey]

BSF is a fine-pitch Whitworth thread.