What is this thread called these days? 3/4"-16 SAE

In other words, what search term ought I to use to find a suitable tap - in all the suppliers.

Thanks

If it's SAE, it would normally have a 60º thread angle, so would be 3/4" x 16 UNS (Unified Special) or possibly UNEF (Unified Extra Fine)

For all practical purposes in the UK 3/4 x 16 UNF is the same thread.

Theoretically there can be small differences in the specifications, particularly if its old, but nothing that will matter to the fit of ordinary threads.

Clive

You've already got the search term,"3/4" - 16 SAE" followed by "tap" works for me. You could always try 3/4" UNF.

Thanks all. TraceyTools came up trumps.

Edited By Kevin Murrell on 22/10/2019 15:36:59

I believe the SAE callout was abandoned many years ago and replaced by UNF.

Also threads marked NF are now UNF.

I was taught that UNC and UNF were replacing (or had replaced) BSW and BSF in the British motor industry, and would be adopted by the rest of the mechanical engineering industries. That was in 1968.

It was a common standard agreed between USA, UK and Canada after the Second World War. Wikipedia says that the system was adopted in 1948.

Wikipedia - Unified threads adopted

Hi, but with the exception of 1"

The one on the left is 1" x 14 NF and the one on the right is 1" x 12 UNF.

Regards Nick.

Thee were some changes made when UNF was ratified, that 12/14 tpi was exactly where the change took place. UNF threads from 1" upwards are now fixed at 12tpi, unless they are UNS, which could be anything.