Specification for quick-release knife

IS 5486: Scope & Key Specifications

• Scope: Covers quick-release knives used for cutting webbings (cotton, flax, nylon) ≥5 mm thick and 75 mm wide.
• Cutting Test (Clause 5.1): Knife must make 3 breadthwise cuts without undue effort; blade edge must remain undamaged.
• Materials: Handle timber must comply with IS 620-1985.
• Marking & Conformity (Clause 6.2): Each knife checked per standard requirements.
• Units: SI units used (e.g., length in metres, force in newtons).
• Rounding Off (Clause 0.3): Final test values rounded per IS 2-1960, matching significant figures of specified values.

Important Units & Definitions (SI Units)

Summary Diagram

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

This ensures knives meet functional and safety criteria per IS 5486.

IS 5486: Materials - Key Specifications & Tables

Timber for Handle Grip (Clause 2.2):

• Must conform to IS 620:1985 (Specification for general requirements for wooden tool handles).
• Typically hardwoods with good strength and durability are preferred.

Steel Forgings:

• Carbon steel forgings should meet relevant specifications for general engineering purposes (second revision).

Units & Symbols (SI Units):

Rounding Off (Clause 0.3):

• Follow IS 2:1960 for rounding values to the same significant digits as specified.

Practical Notes:

• Knife handles use timber per IS 620 for durability and grip comfort.
• Steel parts must comply with standard forging specs for strength.
• Testing involves cutting tests on webbings (Clause 5.1) to ensure blade quality.
• All dimensions are in millimeters.

flowchart TD
    A[Material Selection] --> B[Timber Handle (IS 620)]
    A --> C[Carbon Steel Forgings]
    B --> D[Durability & Grip]
    C --> E[Strength & Toughness]
    E --> F[Cutting Performance Test (Clause 5.1)]

This summarizes essential materials and standards per IS 5486.

IS 5486: Shape, Dimensions, and Construction Summary

1. Knife Specifications (Clause 5.1)

• Used for making 3 complete breadthwise cuts on webbings.
• Webbings: Minimum 5 mm thick, 75 mm wide (cotton, flax, nylon).
• Cutting must be smooth without undue effort or damage to the blade edge.

2. Materials

• Leather sheath: Conforms to IS 581:1976 (vegetable tanned hydraulic leather).
• Thread for stitching: Conforms to IS 1720:1978 (cotton sewing threads).
• Handle timber: Conforms to IS 620:1985.
• Rivets: Hot forged steel, diameter 12-36 mm.

3. Dimensions

• All dimensions are in millimeters.
• Refer to Fig. 1 & Fig. 2 in IS 5486 for detailed knife and sheath dimensions.
• Includes strap for holding knife and loop for belt wearing.

4. Construction Notes

• Knife blade hardness tested by Vickers hardness test.
• Rivets and stitching must ensure durability and safety.

Quick Reference Table: Webbings Cut by Knife

Units & Symbols (SI Units)

flowchart LR
    A[Knife] --> B[Cut 3 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)]

For detailed dimensions and construction, refer to **Figures 1 and

IS 5486: Workmanship and Finish - Key Specifications

• Press Button on Strap (Clause 3.1.2):

  • Must be rust-proof and secure, not undoing by itself.
  • Stitching: Minimum 5 stitches/cm, even and consistent.

• Metal Surfaces (Clause 4.2):

  • Finished as natural bright lacquered to prevent corrosion and maintain appearance.

• Handle Grip Timber (Clause 2.2):

  • Must conform to IS 620:1985 (Specification for wooden tool handles).
  • Ensures durability and ergonomic quality.

• Rounding Off Numerical Values (Clause 0.3):

  • Follow IS 2:1960 rules for rounding test results.
  • Retain the same number of significant digits as the specified value.

Summary Table: Stitching and Finish

flowchart TD
    A[Knife Handle] --> B[Strap with Press Button]
    B --> C{Press Button Quality}
    C -->|Rust Proof| D[Secure Attachment]
    C -->|Not Rust Proof| E[Fail]
    B --> F[Stitching]
    F -->|≥5 stitches/cm| G[Pass]
    F -->|<5 stitches/cm| H[Fail]
    A --> I[Handle Timber]
    I -->|Conforms IS 620:1985| J[Pass]
    I -->|Non-conforming| K[Fail]
    A --> L[Metal Surface]
    L -->|Natural Bright Lacquered| M[Pass]
    L -->|Other Finish| N[Fail]

This ensures durability, safety, and consistent quality in knife handles as per IS 5486.

IS 5486: Performance Test Key Points

1. Performance Test (Clause 5.1)

• Test: Knife must make 3 complete breadthwise cuts on webbings (cotton, flax, nylon).
• Webbing specs: Thickness ≥ 5 mm, Width ≥ 75 mm.
• Criteria: Cutting should require no undue strain or effort.
• Post-test: Cutting edge must not be blunted or damaged.

2. Rounding Off Results (Clause 0.3)

• Final test values rounded per IS 2-1960.
• Retain same significant figures as specified values.

3. Timber Handle (Clause 4.3)

• Handle timber must be polished and coated with at least two coats of clear varnish.

4. Units & Definitions (SI Units)

Summary Table: Performance Test Criteria

flowchart LR
    A[Knife] --> B[Cut 3 times on webbing]
    B --> C{Webbing specs?}
    C -->|Thickness ≥ 5mm & Width ≥ 75mm| D[Cutting performance]
    D --> E{Cutting effort?}
    E -->|No undue strain| F[Pass]
    E -->|Undue strain| G[Fail]
    D --> H{Edge condition?}
    H -->|No damage| F
    H -->|Damage| G

This ensures the knife meets the standard's functional durability and quality.

IS 5486: Marking and Criteria for Conformity (Clause 6.2 & related)

• Marking:

  • Quick-release knife and sheath may carry the ISI Certification Mark (Clause 6.1.1).
  • The ISI mark assures compliance with the standard, verified by ISI's inspection and quality control system.

• Criteria for Conformity:

  • Each knife must be checked against all requirements of IS 5486 (Clause 6.2).
  • Test results must be rounded off as per IS:2-1960, maintaining the same significant figures as the specified values.
  • Knives must perform 3 complete breadthwise cuts on webbings (≥5 mm thick, 75 mm wide, cotton/flax/nylon) without undue effort or blade damage (Clause 5.1).

• Units & Definitions:

  • SI units are used (e.g., length in meters, force in newtons).
  • Important derived units include:

Summary Table: Knife Conformity Checks

flowchart TD
    A[Manufacture Knife] --> B[Perform Cutting Test]
    B --> C{Cuts meet criteria?}
    C -- Yes --> D[Check Blade Condition]
    D --> E{Blade undamaged?}
    E -- Yes --> F[Mark with ISI Mark (optional)]
    E -- No --> G[Reject/Rectify]
    C -- No --> G[Reject/Rectify]

This ensures the knife meets quality and safety standards per IS 5486.