Attention machinists and workshop pros! This Shars 5/8 R8 collet is all about precision and reliability. With a super tight TIR of just 0.0006, you're getting exceptional accuracy for your milling operations. The drawbar thread size is 7/16x20UNF, which is standard for most R8 spindle machines. What really sets this collet apart is the construction - it's made from the highest grade steel available, then precision ground to those close tolerments we all need for quality work. The fact that it's hardened and ground throughout means it's built to last through serious use without wearing out or losing its accuracy. Whether you're running production work or doing precision hobby machining, having collets that hold tools securely and accurately is everything. This 5/8 size is perfect for holding larger end mills, drills, and other cutting tools. The quality control Shars puts into these collets means you can trust them job after job. No more worrying about tool runout affecting your finish quality or dimensional accuracy. If you're tired of cheap collets that can't hold tolerance, this is the upgrade your machine deserves. Seriously, for the price, you're getting professional-grade precision that'll make a noticeable difference in your work quality.