Nitto Technomic NTC-150 1 Inch Quill Stem - 26.0 mm Clamp

I recommend this product

Surprised to see rec'd bar-clamp torque is 14–16 Nm, that's a lot! But no worries with this stem, the steel clamp bolt goes through into a nut on the back, so you'll never overtighten and damage the threads of a blind socket in the alloy head. So — a good solid grip. Also a full range of sizes, and at the reduced price of £40 I'd call this a bargain. And the shine comes up very well for a brisk polish with Autosol.