Roll Necks: Diameter tolerance h6/h7, Taper angle 1:12 or 1:30

Component Specifications

Definition

Roll necks are precision-machined cylindrical extensions at both ends of backup rolls in rolling mills, designed to interface with bearings and drive systems. They provide structural support for the roll body while transmitting torque from the drive mechanism and withstanding significant radial and axial loads during metal forming operations. Critical dimensions include diameter, length, taper angles, and surface finish specifications to ensure proper bearing fit and alignment.

Working Principle

Roll necks function as mechanical interfaces that transfer rotational motion from drive systems to the roll body while supporting the roll's weight and operational loads through bearing assemblies. They maintain precise alignment between rolls to ensure uniform material deformation during rolling processes.

Materials

Typically forged alloy steel (e.g., 42CrMo4, 34CrNiMo6) with surface hardening (induction hardening or nitriding) to 55-62 HRC. High-strength steel grades with excellent fatigue resistance and toughness properties.

Technical Parameters

Parameter	Typical range	Notes & selection driver
Taper Angle	1:12 or 1:30
Straightness	≤ 0.05 mm/m
Hardness Depth	3-8 mm
Runout Tolerance	≤ 0.02 mm
Surface Roughness	Ra 0.8-1.6 μm
Diameter Tolerance	h6/h7

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards

ISO 286-2, DIN 7154, ISO 2768-mK

Parent Products

This component is used in the following industrial products

Backup Rolls

Large-diameter rolls that support the work rolls in a rolling mill, absorbing rolling forces and maintaining roll alignment.

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Engineering Analysis

Risks & Mitigation

Bearing seizure due to improper fit
Fatigue cracking from cyclic loading
Surface damage from contamination
Misalignment causing uneven wear
Thermal stress from operational heating

FMEA Triads

Trigger: Insufficient lubrication or contamination
Failure: Bearing seizure and surface scoring
Mitigation: Implement strict lubrication protocols, install filtration systems, and conduct regular oil analysis

Trigger: Cyclic loading beyond design limits
Failure: Fatigue cracking in stress concentration areas
Mitigation: Implement load monitoring systems, conduct regular NDT inspections, and redesign fillet radii to reduce stress concentrations

Trigger: Improper bearing fit or installation
Failure: Fretting corrosion and premature wear
Mitigation: Establish precise fitting procedures, use proper installation tools, and verify dimensions before assembly

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

Geometric tolerances per ISO 1101, dimensional tolerances per ISO 286, surface finish per ISO 1302

Test Method

Dimensional verification with CMM, surface hardness testing with Rockwell or Brinell methods, ultrasonic testing for internal defects, magnetic particle inspection for surface cracks

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation

Request current drawings, revision history, and a signed specification sheet.

Manufacturing capability

Verify equipment lists, process limits, capacity, and representative production evidence.

Inspection readiness

Confirm test methods, calibrated equipment, sampling plans, and traceable reports.

Supplier transparency

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Manufacturers of Roll Necks

Manufacturer profiles associated with Roll Necks.

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Related Components

Work Rolls

Work rolls are precision cylindrical components in heavy-duty rolling mills that directly contact and deform metal during rolling operations.

Venting Channels

Venting channels are precision-engineered passages in metal casting mold cores designed to allow gases to escape during the molten metal pouring process, preventing defects and ensuring high-quality castings.

Aluminum Matrix

Aluminum matrix is the continuous metallic phase in aluminum matrix composites, providing structural integrity and thermal/electrical conductivity in hot-forged aluminum alloy billets.

Grain Structure

The crystalline arrangement of atoms in hot-forged aluminum alloy billets, determining mechanical properties and performance.

Frequently Asked Questions

What is the primary function of roll necks in backup rolls?

Roll necks serve as the mechanical interface between backup rolls and their support bearings, transmitting rotational force from drive systems while supporting the roll's operational loads and maintaining precise alignment during metal forming processes.

Why are roll necks typically surface hardened?

Surface hardening (through induction hardening or nitriding) increases wear resistance and fatigue strength at the bearing contact surfaces, extending component life while maintaining the core material's toughness to withstand shock loads.

What are common failure modes for roll necks?

Common failures include surface spalling from fatigue, scoring from lubrication failure, fretting corrosion at bearing interfaces, and cracking from thermal or mechanical stress concentrations.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification

This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Roll Necks