🔩 HHIP 3900-5129 ER-4 Collet Block Review

This is a well made and accurate tool at a very competitive price. It arrived the very day I needed to make the tension wrench and was much more convenient to use than adjusting the platter. I had to fiddle with the exact dimensions of the part due to some differences in chuck mounts (!), but the block did the checking of the fit and resetting the fixture in the vise all at once - you couldn't do that with a turntable. I also ordered a hex. I have always been happy with H&H tools.

Nice to look at. Arrived well tapped and oily, no fingerprints or corrosion. The nut fits smoothly, but the roughness of the thread is visible. The inner wall cavity showed unpolished tool marks. Experts speak of a concentricity of less than 0.0005" to 0.0002" for quality holders. I measured 0.0012 inside and outside runout when installed in a 3-jaw tool on my 9x18 Chinese lathe with the best flat set. That's about as much as I can get from my spindle and 3 jaws on any setup. I think this will…

Collets slide easily in and out of the collet holder. I use a tool on a milling machine to align work surfaces held by a collet to 90 or 180 degrees. from the 0 degree surface by simply loosening the vise and rotating the square portion of the tool. I made a brass valve for a black powder bottle that required holes of different diameters to be placed at 90 degrees to each other. This tool saved me a lot of time trying to properly align the cylindrical brass rod. With prisms and this tool, the…