{"product_id":"sumitomo-16gc256-pcbn-turning-insert-bn350-55-degree-diamond","title":"Sumitomo 16GC256 Pcbn Turning Insert BN350 55 Degree Diamond","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe SUMITOMO 16GC256 is a Polycrystalline Cubic Boron Nitride (PCBN) turning insert engineered for hard material machining on CNC lathes and turning centers. Manufactured to ANSI code NUDNMA431 and ISO code NU-DNMA150404, this insert features a 55-degree diamond shape, negative rake geometry, and an uncoated BN350 PCBN grade. With a 0.5-inch inscribed circle and a 0.0156-inch corner radius, it is designed for precision single-edge cutting on hardened steels, cast irons, and other hard workpiece materials. CNC machinists and tool-and-die professionals specify this insert for finishing and semi-finishing operations where tight tolerances are required.\u003c\/p\u003e\u003cp\u003eThis insert is suited for hard turning applications in both production and job-shop environments. It is commonly used on horizontal and vertical turning centers handling workpiece materials classified under ISO material group H, which includes hardened steels and hard cast irons. The NUDNMA431 style and N clearance code make it appropriate for profiling and straight turning passes where a rigid, negative-rake setup is preferred. One cutting edge is available per insert.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003ePCBN insert material (Polycrystalline Cubic Boron Nitride) for hard material cutting\u003c\/li\u003e\n\u003cli\u003eBN350 manufacturer grade — uncoated, suited for high-heat hard turning\u003c\/li\u003e\n\u003cli\u003e55-degree diamond insert shape with negative rake for stable cutting geometry\u003c\/li\u003e\n\u003cli\u003e0.5-inch inscribed circle and 0.1875-inch insert thickness for rigid tool engagement\u003c\/li\u003e\n\u003cli\u003eSingle cutting edge with 0.0156-inch corner radius for precise finish passes\u003c\/li\u003e\n\u003cli\u003eHeld by clamp and pin method; conforms to ANSI and ISO 13399 standards\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned as an OEM-style replacement or direct-specification PCBN turning insert for toolholders accepting DNMA-style inserts with a 0.2030-inch hole diameter and clamp-and-pin holding. Confirm holder compatibility against ANSI code NUDNMA431 or ISO code NU-DNMA150404 before ordering.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eInstallation should be performed by a qualified CNC machinist or toolroom technician with the machine powered off and locked out per facility LOTO procedures. Seat the insert fully in the pocket and torque the clamp according to the toolholder manufacturer specifications before engaging the spindle. Handle PCBN inserts with care — edge chipping from improper seating or side loading during installation will reduce cutting life. Verify workpiece material hardness and cutting parameters against the BN350 grade application range before first cut.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eInsert Material\u003c\/strong\u003e: Polycrystalline Cubic Boron Nitride (PCBN)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Grade\u003c\/strong\u003e: BN350\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eANSI Code\u003c\/strong\u003e: NUDNMA431\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eISO Code\u003c\/strong\u003e: NU-DNMA150404\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInsert Shape\u003c\/strong\u003e: Diamond (55-degree included angle)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInsert Shape Code\u003c\/strong\u003e: D\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRake\u003c\/strong\u003e: Negative\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClearance Code\u003c\/strong\u003e: N\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTolerance Code\u003c\/strong\u003e: M\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInscribed Circle\u003c\/strong\u003e: 0.5 inches (12.70 mm)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInsert Thickness\u003c\/strong\u003e: 0.1875 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCorner Radius\u003c\/strong\u003e: 0.0156 inches (1\/64 inch)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHole Diameter\u003c\/strong\u003e: 0.2030 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of Cutting Edges\u003c\/strong\u003e: 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInsert Holding Method\u003c\/strong\u003e: Clamp and Pin\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChip Breaker\u003c\/strong\u003e: A\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrimary Workpiece Material\u003c\/strong\u003e: Hard Material (ISO Code H)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoating\u003c\/strong\u003e: Uncoated\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeries\u003c\/strong\u003e: D\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStandards\u003c\/strong\u003e: ANSI, ISO 13399\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Quantity\u003c\/strong\u003e: 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.2 pounds\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eStandard Information\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: SUMITOMO\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 16GC256\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SUMITOMO","offers":[{"title":"Default Title","offer_id":51747764699442,"sku":"16GC256","price":64.08,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/a6e4c9446040b532765b12770162bc78_33419861-001b-41cc-8d5b-296ae3316687.jpg?v=1788885222","url":"https:\/\/voomisupply.com\/products\/sumitomo-16gc256-pcbn-turning-insert-bn350-55-degree-diamond","provider":"Voomi Supply","version":"1.0","type":"link"}