Specification for quick-release knife
1985 Edition

Scope Overview of the Standard

• This standard governs quick-release knives designed for cutting webbings made of cotton, flax, or nylon with a minimum thickness of 5 mm and width of 75 mm.
• The knife must successfully perform three breadthwise cuts on the webbing without excessive effort, maintaining an undamaged blade edge.
• Handle wood must meet the requirements specified in IS 620-1985.
• Each knife is subject to marking and conformity verification as per Clause 6.2.
• Measurements and tests are conducted using SI units with rounding rules following IS 2-1960.

Key SI Units Applied

Diagrammatic Summary

graph LR
A[Quick-Release Knife] --> B[Cutting Test: 3 breadthwise cuts]
B --> C[Webbing: ≥5 mm thick, 75 mm wide]
A --> D[Handle: Timber per IS 620-1985]
A --> E[Marking and Conformity Validation]

This section assures that knives meet operational and safety standards as laid out in the code.

Materials Specified under the Standard

Handle Wood (Clause 2.2):

• Must comply with IS 620:1985 for wooden tool handles, typically hardwoods offering strength and longevity.

Steel Forgings:

• Carbon steel forgings should adhere to relevant engineering specifications ensuring toughness and durability.

Measurement Units (SI):

Rounding Guidelines (Clause 0.3):

• Numeric test results are rounded according to IS 2:1960 to maintain consistent significant figures.

Practical Insights:

• Handles utilize timber complying with IS 620 for ergonomic grip and durability.
• Steel components meet established forging standards to ensure strength.
• Blade quality is verified through cutting tests on webbings as per Clause 5.1.
• All dimensions are expressed in millimeters.

flowchart TD
    A[Material Selection] --> B[Timber Handles (IS 620)]
    A --> C[Carbon Steel Forgings]
    B --> D[Durability & Ergonomics]
    C --> E[Structural Strength]
    E --> F[Cutting Performance Validation (Clause 5.1)]

This section highlights fundamental material requirements aligned with IS 5486.

Overview of Design and Construction Parameters

Knife Functionality (Clause 5.1)

• Designed to perform three complete breadthwise cuts on webbings.
• Webbings must be at least 5 mm thick and 75 mm wide, made of cotton, flax, or nylon.
• Cutting should be smooth without excessive force or blade edge damage.

Material Details

• Sheath made from leather conforming to IS 581:1976 (vegetable tanned hydraulic leather).
• Stitching thread must comply with IS 1720:1978 (cotton sewing threads).
• Handle timber per IS 620:1985.
• Rivets are hot forged steel with diameters between 12 mm and 36 mm.

Dimensional Information

• All measurements are in millimeters.
• Refer to Figures 1 and 2 in the standard for exact knife and sheath dimensions.
• Knife includes a strap for retention and a loop for attaching to a belt.

Assembly and Finishing Notes

• Blade hardness is determined via Vickers hardness testing.
• Rivets and stitching methods ensure secure, durable construction.

Quick Reference: Webbing Specifications

SI Units Summary

flowchart LR
    A[Knife] --> B[Three Breadthwise Cuts]
    B --> C[Webbing: ≥5 mm thick, 75 mm wide]
    A --> D[Leather Sheath (IS 581)]
    A --> E[Thread (IS 1720)]
    A --> F[Timber Handle (IS 620)]
    A --> G[Hot Forged Rivets (12-36 mm)]

Consult Figures 1 and 2 for detailed dimensions and construction specifics.

Key Aspects of Finishing and Workmanship

• Press Button on Retaining Strap (Clause 3.1.2):

  • Must be resistant to rust and securely fastened to prevent accidental release.
  • Stitch density should be at least 5 stitches per centimeter, uniform and tidy.

• Metal Finishing (Clause 4.2):

  • Metal surfaces are to be finished with a natural bright lacquer to protect against corrosion and maintain aesthetics.

• Handle Wood (Clause 2.2):

  • Must meet IS 620:1985 standards to ensure strength and ergonomic quality.

• Rounding of Measured Values (Clause 0.3):

  • Test results must be rounded following IS 2:1960 guidelines, preserving the significant figures of the original values.

Summary Table: Stitching and Finishing Standards

flowchart TD
    A[Handle Assembly] --> B[Strap with Press Button]
    B --> C{Button Quality}
    C -->|Rust-Resistant| D[Secure Fastening]
    C -->|Not Rust-Resistant| E[Fail]
    B --> F[Stitching]
    F -->|≥5 stitches/cm| G[Pass]
    F -->|<5 stitches/cm| H[Fail]
    A --> I[Timber Handle]
    I -->|Complies IS 620:1985| J[Pass]
    I -->|Non-compliant| K[Fail]
    A --> L[Metal Surfaces]
    L -->|Natural Bright Lacquer| M[Pass]
    L -->|Other Finishes| N[Fail]

This section ensures that knife components meet durability, safety, and quality requirements.

Performance Testing Requirements

Performance Test (Clause 5.1)

• Knife must successfully execute three full breadthwise cuts on webbings made of cotton, flax, or nylon.
• Webbings are required to be at least 5 mm thick and 75 mm wide.
• Cutting should be accomplished without excessive force.
• Post-test, the blade edge must remain sharp and free from damage.

Rounding of Test Results (Clause 0.3)

• Final outcomes should be rounded in accordance with IS 2:1960, maintaining the same number of significant digits.

Handle Treatment (Clause 4.3)

• Handle wood must be polished and coated with a minimum of two layers of clear varnish.

Relevant SI Units

Summary Table: Performance Criteria

flowchart LR
    A[Knife] --> B[Perform 3 cuts on webbing]
    B --> C{Is webbing ≥5mm thick and 75mm wide?}
    C -->|Yes| D[Assess cutting performance]
    D --> E{Cutting effort acceptable?}
    E -->|Yes| F[Pass]
    E -->|No| G[Fail]
    D --> H{Is blade undamaged?}
    H -->|Yes| F
    H -->|No| G

This test confirms the knife's efficiency and durability under emergency use conditions.

Marking Requirements and Conformity Assessment (Clause 6.2 and related)

• Identification Marks:

  • The knife and its sheath may bear the ISI Certification Mark if licensed (Clause 6.1.1).
  • This mark certifies adherence to the standard and quality assurance by ISI.

• Conformity Checks:

  • Every knife must be inspected to verify compliance with all IS 5486 requirements (Clause 6.2).
  • Test data must follow rounding protocols from IS 2:1960.
  • Knife must perform three complete breadthwise cuts on standard webbings without undue effort or blade damage.

• Measurement Units:

  • SI units are standard, including meters for length and newtons for force.

Compliance Verification Table

flowchart TD
    A[Manufacturing] --> B[Conduct Cutting Test]
    B --> C{Cuts meet criteria?}
    C -- Yes --> D[Inspect Blade Condition]
    D --> E{Blade undamaged?}
    E -- Yes --> F[Apply ISI Mark (if licensed)]
    E -- No --> G[Reject or Correct]
    C -- No --> G[Reject or Correct]

This ensures the product meets stringent quality and safety guidelines.