Stable Rough and Semi-Finish Turning of Work-Hardened High Manganese Steel

UHD provides USN100 double-sided vacuum-brazed CBN inserts for rough and semi-finish turning of work-hardened Mn13 and Mn18 high manganese steel. The solution supports stable machining of mining wear parts, railway switch components, and crusher parts under deep-cut and impact-load conditions.

Mn13 and Mn18 high manganese steel can work-harden rapidly during turning. Although the base material is typically HB200–230, the machined surface may harden to HRC50+ under cutting heat and deformation. This creates a demanding production environment for mining wear parts, railway switch components, and crusher parts, especially where deep cuts, interrupted engagement, and impact loads occur together.

For these operations, the key requirement is not simply to cut the material, but to maintain predictable tool life, controlled changeover intervals, and consistent machining output. UHD recommends the Integral Brazed CBN Insert Series – USN100: a double-sided, vacuum-brazed CBN insert designed for roughing and semi-finish turning of work-hardened high manganese steel.

Its double-sided usable structure supports higher cutting-edge utilization, while the integral vacuum-brazed construction helps reduce risks associated with insufficient brazing, insert detachment, and unstable edge performance under fluctuating loads.

High manganese steel turning with UHD USN100 Integral Brazed CBN Insert Series

CBN Insert Selection for Mn13 and Mn18 Turning

Material & Hardness	Typical Workpiece	Machining Condition	Recommended Insert	Vc (m/min)	f (mm/r)	ap (mm)
High manganese steel (Mn13/Mn18, HB200–230 before work hardening, HRC50+ after work hardening)	Mining liners, hammer heads, jaw plates	Roughing, deep cut, low speed	Integral Brazed CBN Insert Series – USN100	60–90	0.25–0.80	4–10
High manganese steel (Mn13/Mn18, HB200–230 before work hardening, HRC50+ after work hardening)	Railway switch components, crusher parts	Semi-finish turning	Integral Brazed CBN Insert Series – USN100	90–135	0.20–0.40	1–3

Process Controls for Repeatable Production

Roughing: Use a sufficiently deep and stable cut to penetrate beyond the repeatedly hardened surface layer. A low-speed, deep-cut strategy helps avoid rubbing and excessive thermal shock.
Semi-finishing: Maintain a constant feed wherever possible. Stable chip thickness is important when stock allowance, interrupted cutting, or local hardening varies across the workpiece.
Rigidity: Minimize tool overhang, secure the workpiece firmly, and provide additional support for long or thin-wall parts. System rigidity is often more decisive than increasing insert hardness.
Trial and standardization: Start within the listed parameter range, adjust only one variable at a time, and document wear patterns, tool life, and abnormal failures before fixing the production standard.

Application Value and Scope

For high manganese steel turning under work-hardening and impact-load conditions, UHD USN100 inserts support a more controllable approach to roughing and semi-finishing. The objective is to reduce brazing-related failure risk, improve tool-life consistency, make insert change intervals easier to manage, and use both sides of the insert more effectively.

This guidance applies to Mn13/Mn18 rough and semi-finish turning. Actual results depend on machine power, setup rigidity, workpiece condition, coolant practice, interruption level, and cutting parameters. For fine finishing, very small depths of cut, or high surface-finish requirements, the insert geometry and machining strategy should be evaluated separately.