{"product_id":"flex-hone-gb31224-3-1-2ft-240-grit-silicon-carbide-precision-finish","title":"Flex-Hone GB31224 3-1\/2ft 240 Grit Silicon Carbide - Precision Finish","description":"\u003cp\u003eIn this review of the Flex-Hone GB31224, the bottom line is straightforward: this 3-1\/2' 240 grit silicon carbide hone is for mechanics and machinists who need a reliable, oil-retaining crosshatch finish on mild steel, stainless, cast iron and other softer ferrous materials. The reviewer found it especially useful for rebuilding hydraulic and engine cylinders where a true plateau finish and consistent grit size matter. It is a quality, USA-made option that simplifies deburring and surface prep while producing repeatable results when used with the correct bore size.\u003c\/p\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMade in the USA:\u003c\/strong\u003e Built by the original inventor, the tool offers consistent manufacturing quality and durability you can rely on in a professional shop.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngineered oversize design:\u003c\/strong\u003e The intentionally oversized construction makes the tool self-centering and self-aligning for easier use and more uniform contact across the bore.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e240 grit silicon carbide abrasive:\u003c\/strong\u003e Delivers a fine plateau finish typically in the 24-32 microinch range, suitable for oil retention and smooth sliding surfaces.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCrosshole deburring capability:\u003c\/strong\u003e Finishing and deburring are accomplished in a single setup, saving time on valves, pumps and cylinder work.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVersatile mounting:\u003c\/strong\u003e Works in a hand drill, drill press or CNC spindle so it integrates into common shop workflows with minimal fuss.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecified fit:\u003c\/strong\u003e Supplied for 3.251'-3.500' bores with a 0.310' shank and 13.5' overall length for predictable compatibility.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eWho It's For\u003c\/h2\u003e\n\u003cp\u003eThe Flex-Hone GB31224 is aimed at engine rebuilders, hydraulic technicians and home machinists who need a fast way to restore cylinder walls and create an oil-holding crosshatch. It performs best when used for mid-size bores in the specified diameter range and where a plateau finish is preferred over aggressive material removal.\u003c\/p\u003e\n\u003cp\u003eThose who should look elsewhere include users needing heavy stock removal or abrasive action on very hard alloys beyond the intended softer ferrous materials. Also, if you do not have access to a stable rotating spindle or proper speed control, results may be inconsistent.\u003c\/p\u003e\n\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eProduces a uniform plateau crosshatch that improves lubrication retention and sliding action.\u003c\/li\u003e\n\u003cli\u003eEasy to use and self-centering, which reduces fixturing time and alignment fuss.\u003c\/li\u003e\n\u003cli\u003eDurable construction with consistent grit for repeatable finishes across multiple uses.\u003c\/li\u003e\n\u003cli\u003eCombines deburring and finishing in one pass, saving operational time.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eNot intended for heavy stock removal; it is a finishing tool rather than a cutter.\u003c\/li\u003e\n\u003cli\u003eRequires correct bore sizing and a suitable spindle speed for best results.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct\u003c\/td\u003e\n\u003ctd\u003eGB31224 FLEX-HONE\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiameter\u003c\/td\u003e\n\u003ctd\u003e3.500' (89mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAbrasive\u003c\/td\u003e\n\u003ctd\u003e240 grit silicon carbide\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIntended materials\u003c\/td\u003e\n\u003ctd\u003eMild steel, stainless steel, cast iron and softer ferrous materials\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFit bore range\u003c\/td\u003e\n\u003ctd\u003e3.251' - 3.500'\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShank and length\u003c\/td\u003e\n\u003ctd\u003e0.310' shank, 13.5' overall length\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTypical finish\u003c\/td\u003e\n\u003ctd\u003e24 - 32 Microinch (0.6 - 0.8 Micrometer)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch2\u003eOur Verdict\u003c\/h2\u003e\n\u003cp\u003eThe Flex-Hone GB31224 is a dependable finishing tool for anyone rebuilding cylinders or prepping bores for seals and rings. It offers clear value for its intended use thanks to a proven design, consistent 240 grit abrasive and easy operation. Buy it if you need a repeatable plateau finish and oil-retaining crosshatch in the specified bore range; skip it if you need aggressive material removal or work outside the supported materials.\u003c\/p\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eWhat bore sizes does this hone fit?\u003c\/strong\u003e\u003cbr\u003eIt is designed for bores between 3.251' and 3.500'.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan it be used in a hand drill?\u003c\/strong\u003e\u003cbr\u003eYes, it can be run in a hand drill, drill press or compatible CNC spindle with appropriate speed control.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat finish will it produce?\u003c\/strong\u003e\u003cbr\u003eThe 240 grit silicon carbide typically yields a plateau finish of about 24-32 microinch, ideal for oil retention.\u003c\/p\u003e","brand":"Flex-Hone","offers":[{"title":"Default Title","offer_id":48617807544539,"sku":"B002XUL1EE","price":48.79,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/61f9Ueb7-8L._SL1176_520e8d34-162c-42f7-a320-c952809b5fd9.jpg?v=1778450267","url":"https:\/\/gearmusthave.com\/products\/flex-hone-gb31224-3-1-2ft-240-grit-silicon-carbide-precision-finish","provider":"GearMustHave","version":"1.0","type":"link"}