7/16” Horsetail?

Slowcoach · Aug 29, 2022

Hi, the hose split on my dunlop tyre inflator and thought I’d replace the hose. Temporarily cut and shut but it’s only 6mm ID and has a odd fitting size on the end that connects to the body. The in and lance end are 1/4” bsp but can’t work out the other end. Seems to measure 10.88mm/0.428 parallel with 19 tpi. Any offers, thanks.

Agroshield · Aug 29, 2022

There is no standard thread of that diameter and pitch. The closest to what you show is 7/16"-18 BSF. Over the four threads in the picture, the total difference between 18tpi and 19tpi is only 11 thou', so it is hard to be certain.

If you do not have a screw pitch gauge, 5/16" BSW, 5/16 UNC, 9/16 UNF and 5/8 UNF are all 18tpi and could be used to see if they fit the threads better or worse than the brass fitting.

brightspark · Aug 29, 2022

wondered what the post was there on 1st look horsetail :laughing:

hose tail

Slowcoach · Aug 29, 2022

brightspark said:
wondered what the post was there on 1st look horsetail hose tail

Couldn’t decide to put it here or how does your garden grow.
Oh dear, bloody tech thinks it’s clever.

Slowcoach · Aug 29, 2022

Agroshield said:
There is no standard thread of that diameter and pitch. The closest to what you show is 7/16"-18 BSF. Over the four threads in the picture, the total difference between 18tpi and 19tpi is only 11 thou', so it is hard to be certain.

If you do not have a screw pitch gauge, 5/16" BSW, 5/16 UNC, 9/16 UNF and 5/8 UNF are all 18tpi and could be used to see if they fit the threads better or worse than the brass fitting.

here’s what pitch gauge tells me. Nothing conclusive and the diameter throws everything to the 4 winds, I can only get close with the bsp pitch.