UHD | Ultrahard Cutting Tool Solutions

Images of hard turning workpieces for high-chromium rolls

Typical Workpieces and Machining Challenges

After heat treatment to HRC58–64, work rolls, cold rolls, backup rolls, and straightening rolls may experience intermittent impact at the roll shoulder fillets, tool marks, and differences in material structure; the outer diameter of long rolls places even higher demands on wear consistency and dimensional retention.

Typical PartsWork rolls, cold rolls, backup rolls, straightening rolls

Processing MaterialHigh-chromium cast iron, high-chromium steel, alloy cast steel

Heat treatment hardnessHRC58–64

Critical areasRoll body OD, roll neck, end face, roll shoulder, and various grooves

Core solution logic: matching insert structure to process load

Hard turning of rolls is not suitable for a single insert to cover all operating conditions. UHD breaks down different areas and loads into matched configurations: roughing focuses on impact resistance, finishing focuses on wear resistance and surface consistency, final finishing focuses on edge stability, and groove machining uses dedicated formed structures.

01Rough turning for impact resistance

Handles large stock variation and interrupted cutting loads, reducing the risk of edge chipping.

02Finish turning for stable wear resistance

Controls wear behavior and reduces dimensional drift and roughness fluctuations.

03Final finishing for precision retention

Supports roll geometry and surface quality control with stable edge performance.

04Dedicated forming for groove machining

Matched to groove constraints, concentrated loads, and chip evacuation conditions.

Recommended CBN Insert Modules

On desktop, hover over the corresponding module to view the applicable process and images; on mobile, all module information will be displayed in full. Specific grades, edge preparations, and cutting parameters should be confirmed based on machine rigidity, clamping method, stock allowance, and cutting conditions.

Rough machining: Integral brazed CBN insert series

Suitable for interrupted or stock-variable conditions such as roll body OD, roll neck rough turning, and roll shoulder fillets. The fully brazed structure is designed primarily for impact loads and anti-chipping requirements, providing a more stable foundation for subsequent finishing.

Finishing: coated CBN insert series

Suitable for high-speed finish turning of batch-produced rolls. The coating and substrate system are designed to support wear resistance and thermal stability, helping reduce surface roughness and dimensional consistency variations caused by insert wear dispersion.

Ultra-finishing: solid CBN insert series

Designed for final machining of cold rolls, precision straightening rolls, and similar applications. The solid structure emphasizes edge consistency and machining stability, making it suitable for scenarios with higher requirements on roll geometry accuracy and surface quality.

Long-stroke OD machining: full face CBN insert series

Suitable for continuous cutting on extra-long roll outer diameters. Designed for long-distance machining where wear accumulation, frequent tool changes, and consistency risks caused by tool changes are concerns, it serves as a life-oriented configuration.

Groove machining and forming: CBN grooving insert series

Suitable for lubrication grooves, annular locating grooves, relief grooves, and similar machining tasks. Grooving conditions involve strong geometric constraints, concentrated loads, and chip evacuation challenges; the dedicated structure helps control groove profile deviation, chipping, and abnormal chip flow.

Fully brazed CBN insert series product image

Full-face CBN insert series product image

CBN grooving insert series product image

Typical application scenarios and configuration approach

Rough machining of work rolls and backup rolls

Problem：Large stock removal combined with interrupted impact can easily cause chipping and unplanned tool changes.

Configuration:Separate roughing and finishing inserts; use fully brazed CBN inserts as the priority choice for the roughing stage.

Batch hard turning finishing

Problem：Variation in insert life can lead to fluctuations in surface quality and dimensional drift.

Configuration:Use coated CBN inserts as the standard finishing solution, focusing on wear consistency and thermal stability.

Final machining of cold rolls or precision straightening rolls

Problem：When roll surface quality requirements increase, conventional finish turning may struggle to maintain stable geometry and surface condition.

Configuration:Use the solid CBN insert series for final machining, focusing on stable edge performance and accuracy retention.

Long rolls and lubrication groove machining

Problem：Wear accelerates over long strokes, and groove machining may also cause profile deviation and chip evacuation issues.

Configuration:Use full-face CBN for the OD and dedicated CBN grooving inserts for lubrication grooves, locating grooves, and similar features.

Solution value: from single-pass tool selection to repeatable process management

Improved machining continuity:For rough machining stages, load-matched configurations help reduce the risk of process interruption caused by chipping.
Stable roll surface quality:Separating finish turning and ultra-finishing helps control the consistency of cylindricity and surface finish.
Lower overall machining loss:Life-oriented configurations for long-stroke OD machining reduce tool changes and the resulting cycle-time losses.
Supports future expansion:Based on non-standard groove profiles, machine rigidity, and process fluctuations, the solution can be extended to custom tooling, parameter guidance, and regrinding/refurbishment services.

UHD offers CBN and diamond material R&D, digital manufacturing, and precision inspection capabilities, enabling a collaborative workflow around material selection, process matching, custom validation, and delivery follow-up.

Stable, High-Precision Hard Turning Solutions for HRC58-64 High Chrome Rolls