Some time back I bought a thermostatic shower bar mixer on Ebay. I thought I had got a bargain but now coming to try and fix it I have found that one of the captive inlet nuts is unthreaded - bugger bugger bugger!
The nut is held on by what I presume, though I can't be sure, is a threaded brass insert which has an about 10mm round internal profile with 6 grooves, a torx bit fitted into the grooves but not well enough to give enough torque to release the insert - if in fact it is threaded.
Any ideas what the key to fit the insert is called and is it likely to be threaded?
TIA
H