Abstract: A nut device which comprises a hollow body structure having a side wall, end walls, and a tapered bore, the body structure defining a longitudinal axis; a sleeve extending in the body substantially coaxially therewith, the sleeve having a longitudinally extending split, and a side taper engaging the body structure tapered bore, the sleeve having a bore thread; an anchor pin extending longitudinally endwise in the split and anchored to at least one of the body structure end walls, for blocking rotation of the sleeve, while allowing sleeve longitudinal movement relative to the pin and body structure; at least one of the body structure end walls having a bore in alignment with the sleeve bore threading; whereby the nut device may be rotatably connected to a longitudinally extending member having threading engaging the sleeve threading, and locked to the member by squeezing the sleeve, in response to sliding engagement of the sleeve side taper with the body tapered bore.