{"product_id":"5770-5-16-close-fit","title":"Robert Charles Plain Shank Counterbore M35-HSS-E 5% Cobalt - 5\/16 Cap Screw Size - 0.312 Pilot Size","description":"\u003cdiv\u003e\n\u003cp\u003eThe Robert Charles Plain Shank Counterbore is a high-performance cutting tool designed for precision counterboring in metalworking. Built from M35 HSS-E with 5% cobalt, it delivers exceptional heat resistance, wear life, and cutting performance for engineers, machinists, and automotive professionals who demand dependable results.\u003c\/p\u003e \u003cul\u003e\n\u003cli\u003e\n\u003cb\u003eMaterial\u003c\/b\u003e: M35 HSS‑E with 5% cobalt, delivering enhanced heat resistance and wear resistance for longer tool life in demanding metals.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eShank Type\u003c\/b\u003e: Plain shank for straightforward fitment in standard tool holders, ensuring stable, repeatable machining.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003ePilot Size\u003c\/b\u003e: 0.312 inch pilot to guide the bore with precision and maintain alignment throughout the cut.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eCap Screw Size\u003c\/b\u003e: 5\/16 cap screw compatibility for secure installation in appropriate tooling setups.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eCounterbore Geometry\u003c\/b\u003e: Optimized cutting edges and flute geometry for clean, square counterbores and consistent bottom finishes.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eApplications\u003c\/b\u003e: Suited to precision engineering, automotive manufacturing, and general workshop use where durability and reliability matter.\u003c\/li\u003e\n\u003c\/ul\u003e \u003cp\u003eWith its cobalt-enhanced alloy and a plain shank designed for standard holders, this counterbore supports repeatable depth control and smooth chip flow, reducing heat buildup and wear during extended operation. The 0.312 inch pilot fosters accurate bore guidance, while the 5\/16 cap screw sizing ensures quick, secure setup. For practitioners performing high-tolerance assemblies or precision pocket counters, this tool delivers dependable performance, helping streamline workflows and reduce rework in metal fabrication and repair environments.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Robert Charles","offers":[{"title":"Default Title","offer_id":43411727908942,"sku":"5770-5\/16-CLOSE FIT","price":47.4,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0560\/3747\/4382\/files\/Robert_Charles_Counterbores_9f565f86-6edd-45dd-8f9a-d35186766c4a.png?v=1769685316","url":"https:\/\/www.protool-ltd.co.uk\/products\/5770-5-16-close-fit","provider":"Protool Precision Tools","version":"1.0","type":"link"}