Professional ISO 2491:1974 Key Cutting Standard Guide

International standard defining specifications for key cutting including depth measurements, spacing requirements, tolerance limits, and material requirements for mechanical keys used in locks and security systems. Access comprehensive professional guidance for implementing industry-standard key cutting procedures with precision manufacturing compliance.

Standard Overview

Publication Date

1974 (First Edition)

Status

International Standard

Application

Mechanical Key Systems

Scope

Key Cutting Specifications

Technical Specifications

Key Depth Specifications

Parameter Specification Tolerance Notes
Minimum Depth 0.5 mm ±0.025 mm Shallow cut limit
Maximum Depth 7.0 mm ±0.025 mm Deep cut limit
Standard Increments 0.25 mm ±0.025 mm Common depth steps
Precision Tolerance ±0.025 mm N/A Manufacturing precision

Spacing Requirements

Parameter Specification Tolerance Notes
Minimum Spacing 2.5 mm ±0.05 mm Between cut centers
Standard Spacing 3.0 mm ±0.05 mm Recommended spacing
Maximum Spacing 15.0 mm ±0.1 mm Extended spacing limit
Edge Distance ≥1.5 mm ±0.05 mm From key edge

Material Requirements

Material Hardness

Minimum Hardness: HRC 45
Maximum Hardness: HRC 65
Recommended: HRC 50-60

Surface Finish

Surface Roughness: Ra ≤ 1.6 μm
Cut Surface: Ra ≤ 3.2 μm
Edge Quality: No burrs

Dimensional Stability

Temperature Range: -40°C to +80°C
Thermal Expansion: ≤ 12 × 10⁻⁶/°C
Corrosion Resistance: Grade 3 minimum

Implementation Guidelines

Equipment Requirements

  • Key cutting machine with precision depth control (±0.025mm)
  • Calibrated measuring instruments (micrometers, depth gauges)
  • Proper cutting tools with appropriate geometry
  • Environmental controls for temperature and humidity
  • Quality control inspection equipment

Cutting Procedures

  • Verify key blank material compliance before cutting
  • Calibrate cutting machine to standard specifications
  • Maintain consistent cutting speed and feed rate
  • Inspect each cut for depth accuracy and surface finish
  • Document all measurements and deviations

Quality Assurance

  • Regular calibration of measuring equipment
  • Statistical process control for cut dimensions
  • Batch testing and documentation
  • Traceability of materials and processes
  • Continuous improvement procedures

Compliance Checklist

Dimensional Compliance

Material Compliance

Process Compliance

Frequently Asked Questions

What is ISO 2491:1974?

ISO 2491:1974 is an international standard that defines specifications for key cutting including depth measurements, spacing requirements, and tolerance limits for mechanical keys used in locks and security systems. This standard complements ISO 9001:2015 quality management systems and follows IEC 60068-2-6 environmental testing protocols for optimal manufacturing precision and reliability.

What are the key depth specifications in ISO 2491:1974?

The standard specifies key depths ranging from 0.5mm to 7.0mm with tolerance limits of ±0.025mm for precision cutting and proper lock operation. These specifications align with ANSI B18.2.1 dimensional standards and DIN 18252 mechanical key requirements for professional manufacturing compliance and quality assurance.

What is the minimum cut spacing requirement?

ISO 2491:1974 requires a minimum spacing of 2.5mm between cuts to ensure structural integrity and prevent key breakage during use.

Does this standard apply to motorcycle keys?

Yes, ISO 2491:1974 applies to all mechanical keys including motorcycle keys, providing universal specifications for key cutting operations across different vehicle types.

Downloads and Resources

ISO 2491:1974 Standard Document

Complete standard specification (PDF format)

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Compliance Calculator

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Inspection Checklist

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Tolerance Analysis Tool

Statistical analysis for manufacturing tolerances

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