Hey there machinists! This handy 5C collet stop is exactly what you need for precision work on your lathes, chuckers, mills, and CNC machines. It fits perfectly inside any 5C spindle with at least 1-1/16\ I.D. and works with standard 5C collets that have both internal and external threads (collets not included, sorry!). The cool part? It's got this machinable adjuster rod with 7/16-20 TPI jam nut that makes fine-tuning super easy - just use a screwdriver on the slot at the end. When you tighten that jam nut against your collet, this thing locks in place rock solid. Perfect for accurately positioning parts up to 7/8\ diameter. The full hex design means you can use whatever wrench you've got handy, and the black oxide finish is hardened to last through plenty of shop use. Seriously, if you're tired of guessing where your parts are positioned, this collet stop will become your new best friend in the workshop. It's one of those simple tools that just makes everything more precise and way less frustrating. Whether you're running production jobs or just doing one-off parts, having consistent positioning makes all the difference in your finish quality and setup time. The internal thread is specifically 1-3/64-24, so it'll work with all your standard threaded collets. No more fiddling around with makeshift solutions - this is the proper tool for the job that'll save you time and improve your accuracy from the first use.