Profile: Stafford Special Tools, Knurls-SST.com Division is a manufacturer of precision knurl holders. We provide a wide array of general machining needs working with all types of materials. We are also a distributor of the highest quality precision knurling tool holders. We offer bump type knurl holders, angular bump knurl holders, round shank bump knurl holders, internal knurling holders, and face knurling holders. Our products include three die precision end rolling heads & heavy duty synchronized rolling heads. We also offer self-centering bump knurl holders, compact precision type adjustable straddle holders, heavy duty type adjustable straddle holders, and turret mounted knurl holders.