As has been suggested, I bet the gun is NPT - the angle of dangle of the thread form is 55 deg rather BSP of 60 degree. But at this size, with tape or sealant it will be fine.- the fitting is to make a tapered sealant joint into the tool, and a parallel ( easily removed for oiling ) joint onto the Whip.).
- I understand the ptfe application process. Normally this just scrunches the ptfe tape, but this badly cut tapered joint really, really minces it up into fragments when you undo it.
Never had a problem with other tapered joints, sure you might have to pick out the odd strand etc. But not a load of fragments and residue bits in the galling on the female threads.
- Totally agree, the last thing I wanted to do was tap into the tool - but in this case I made the exceptional choice.
hence would like advice on the tapping of tapered threads.
if it works, make life easy from then on.
As others have said - screw the hose into the gun and leave it alone. Before using it, drip a couple of drops of oil into the hose and then use it - the air flow will carry it into the gun perfectly well, and possibly better as it will be atomised rather than a glug of oil.
These threads have been around a long time, as have the tools - no need to over-complicate things.