Flank Wear(mm) Grooving External grooving GDM/GDMS/GDGS type KGD-JCT (for automatic lathe) Cut-off holders for high pressure coolant with long tool life The optimized coolant hole position effectively cools the cutting edge 1 Optimized coolant hole position 2 Discharge coolant towards the flank face of the insert G Coolant discharging KGD-JCT Competitor A Sufficient cooling towards the Coolant does not flow directly cutting edge towards the cutting edge Effective cooling of the cutting edge Wear resistance comparison (internal evaluation) Cutting edge condition (after machining 20 minutes) 0.20 0.15 KGD-JCT Competitor A (Internal coolant type) KGD-JCT Competitor A 0.10 High density and high speeds coolant provides effective cooling of the 0.05 cutting edge Superior cooling action improves tool life 0.00 0 20 40 60 80 Cutting Time (min) Cutting conditions: Vc = 80 m/min, f = 0.06 mm/rev (~2 mm: f = 0.02 mm/rev), KGDR1625H-2-JCT, GDM2020N-015PF PR1535 (Edge width: 2.0 mm) Workpiece material : SUS304 (ø25), internal coolant (1.5MPa) Cut-off G31