Sandvik CNGN120708T01020 670 CNG452T0320 Ceramic Turning Insert (7 pcs)

These are new Sandvik Coromant CNGN120708T01020 grade 670 ceramic turning inserts (ANSI equivalent CNG452T0320), sold as a full factory tray of 10 pieces. Decoding the ISO designation: C = 80° rhombic shape, N = 0° clearance angle, G = close tolerance (±0.025 mm IC / ±0.13 mm thickness), N = no chipbreaker/hole (solid insert), 12 = 12.7 mm inscribed circle, 07 = 7.94 mm thickness, 08 = 0.8 mm nose radius, T01020 = honed/chamfered cutting edge preparation. Grade 670 is a Sandvik hot-pressed silicon nitride (Si₃N₄) ceramic grade, characterised by its distinctive light-blue/grey appearance visible in the photos; it is engineered specifically for high-speed dry roughing and semi-finishing of grey cast iron and nodular cast iron at cutting speeds of 500–1500 m/min. The solid, uncoated Si₃N₄ body delivers exceptional hot hardness and thermal shock resistance, making grade 670 a benchmark choice for automotive powertrain components such as brake discs, engine blocks, and cylinder liners where carbide speeds are insufficient. Compatible toolholders require a CNGN/CNG style pocket with 0° clearance; Sandvik Coromant DCLNR/L and equivalent negative-rake holders are typical pairings.

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