Unfortunately, you are not measuring the o.d. accurately enough. It is a little larger than 3/8" (0.375") - around 0.383", because the thread is 1/8"BSP.I know that it's 28TPI and 3/8 dia, but I can't find a thread that matches that, it's certainly not UNF.
Thanks. I should have thought about BSP. I can't afford Aldi or Lidl I've got Triumph bits to buyUnfortunately, you are not measuring the o.d. accurately enough. It is a little larger than 3/8" (0.375") - around 0.383", because the thread is 1/8"BSP.
Next time Aldi or Lidl have digital calipers, I recommend a couple, more accurate than a ruler.![]()
They're surprisingly cheap for the quality - both of mine were about £8; I bought two because I thought the first might be fragile but they've both survived so far. I had intended keeping the second one boxed up in case the first one failed at the wrong time but the workshop pixies keep borrowing one or the other ...can't afford Aldi or Lidl