CBN Small Round Insert RCGN120400S02520

The YLHH RCGN120400S02520 is a fine-grain PCBN insert engineered for precision finishing of small-diameter internal bores, micro-turning, and medical-grade surface requirements. With a 12.7 mm inscribed circle, positive rake, Class G tolerance, and Grade FB-2 (~50% CBN), it consistently achieves Ra 0.4–0.8 µm on hardened steel HRC 45–62.

Key Features

• Compact round geometry — minimum bore diameter as low as 14 mm (holder dependent)
• Positive rake for low cutting forces and excellent surface finish
• Grade FB-2 fine-grain PCBN optimized for finishing passes
• Class G precision tolerance for consistent seat contact
• Individual slot packaging protects cutting edges during storage

Recommended Cutting Parameters

• Workpiece hardness: HRC 45–62 (bearing steel, medical implants, precision shafts)
• Cutting speed (Vc): 120–250 m/min (dry or high-pressure coolant)
• Feed rate (f): 0.02–0.10 mm/rev (light finishing feeds)
• Depth of cut (ap): 0.05–0.5 mm

Typical Applications

• Small bore finishing after hardening (hydraulic valves, nozzles)
• Precision facing on miniature components
• Micro-turning of surgical instrument parts
• Final finishing pass replacing grinding on selected features

Tool Holder Compatibility

• ISO RCGN 120400 standard small round insert geometry
• Compatible with SCLCR/L, STFCR micro-boring bars
• Use sharp, well-maintained holder for best surface results