Specification for door handles for mortice lock (vertical type)

IS 4992: Scope - Key Points & Specifications

Scope:
IS 4992 covers materials and specifications for builder's hardware, especially door handles for mortice locks (vertical type), including related components.

Key Material Requirements (Table Extract)

Sampling & Quality Control (Table 2)

Rounding off Test Results

• Follow IS 2-1960 for rounding test/analysis results.
• Retain significant places same as specified values.

SI Units Used in IS 4992

IS 4992: Type and Size - Key Specifications

Material Thickness & Grades for Door Handles (Vertical Type Mortice Locks)

Bend Test for Mild Steel Sheet (Clause 1.6b)

• Bend 180° at room temperature
• Axis parallel to rolling direction
• Bend around twice the thickness
• No fracture or cracking on outer bend surface

Tensile Strength & Elongation for Mild Steel Bar (Connecting Rod)

• Tensile Strength: ≥ 32 kgf/mm² (≈ 314 MPa)
• Elongation: ≥ 26%

Summary:

• Brass sheet: min 1.6 mm thick, Alloy CuZn 40 (IS: 410)
• Mild steel sheet: min 1.6 mm thick, Grade 0-1079, passes bend test
• Connecting rod: Mild steel bar with tensile strength ≥ 32 kgf/mm², elongation ≥ 26%
• Aluminium rods: IS HE 30-WP grade extruded sections
• Spring parts: Spring steel per IS: 4454

flowchart TD
    A[Door Handle Parts] --> B[Brass Sheet (1.6

IS 4992 - Materials for Door Handles (Mortice Locks, Vertical Type)

Additional Material Requirements:

• Mild steel sheet bend test: Bend 180° around twice thickness without cracking (IS: 1079-1973, Grade 0-1079).
• Connecting rod: Mild steel bar with tensile strength ≥ 32 kgf/mm², elongation ≥ 26% (IS: 1977-1969, Grade St 32-0) or Aluminium extruded rod (IS: 733-1967, HE 30-WP).
• Spring components: Spring steel Grade 1 or 2 (IS: 4454-1967).

Finish Specifications (Clause 8.1):

• Brass: Natural or bright electro-chromium plated.
• Aluminium alloy: Anodized, min Grade AC 10 (IS: 1868-

IS 4992: Manufacture and Construction - Key Specifications

1. Material Requirements for Door Handles (Mortice Locks - Vertical Type)

2. Manufacturing Notes

• Brass castings: Minimum 60% copper content; free from blow holes and surface defects.
• Aluminium alloy pressure die-castings: Minimum 2 mm thickness (Grades A-5-M or A-6-M of IS).
• Zinc base alloy pressure die-castings: Minimum 2 mm thickness (Alloy 1 or 2 of IS).

3. Bend Test for Mild Steel Sheet

• Bend axis parallel to rolling direction.
• Bend through 180º around twice the thickness.
• No fracture/cracking on the outside.

Summary Diagram: Material Selection Flow for Door Handles

flowchart TD
    A[Select Part] --> B{Material Type}
    B -->|Brass Sheet| C[Cast brass CuZn 40, 1.6 mm min]
    B -->|Mild Steel Sheet| D[Bend test, Grade 0-

IS 4992: Dimensions and Tolerances for Door Handles (Mortice Locks - Vertical Type)

Key Points from Clause 5.1 & Related Sections:

• Door handles must conform to dimensions and tolerances as per Fig. 1 (not provided here).
• Connecting rod must fit snugly in the follower and socket handle, ensuring positive operation (Clause 4.2).
• Material thickness and grades are specified for various parts (see Table 1 excerpt).

Material Thickness & Grades (Summary from Table 1):

Tolerances:

• Exact dimensional tolerances are per Fig. 1 (typically ±0.1 to ±0.5 mm depending on part).
• Bend test for mild steel sheet sprocket: bend 180° around twice thickness without cracking.

Additional Notes:

• Materials must be free from casting defects (blow holes, surface defects).
• Manufacturer must provide material compliance certificates per Clause 2.2.

IS 4992 - Performance Requirements Summary

Key Material Requirements (Clause 6):

Bend Test Criteria for Mild Steel Sheet:

• Bend test at room temperature
• Bend through 180° around a mandrel of diameter = 2 × thickness
• No fracture or cracking on the outside surface

Tensile Strength & Elongation for Mild Steel Bars:

• Tensile Strength: ≥ 32 kgf/mm² (~313 MPa)
• Elongation: ≥ 26%

Notes:

• Thickness and mechanical properties ensure durability and performance.
• Manufacturer and purchaser may agree on other shapes/dimensions (Clause 5.1.1).
• Material certificates must comply with corresponding IS standards (Clause 9).

flowchart TD
    A[Material Selection] --> B{Material Type}
    B -->|Brass Sheet| C[CuZn 40 Alloy, ≥1.6mm]
    B -->|Mild Steel Sheet| D[Bend Test: 180° around 2× thickness]
    B -->|Mild Steel Bar| E[Tensile ≥32 kgf/mm², Elongation ≥26%]
    B -->|Aluminium Rod| F[Grade HE 30-WP]
    B -->|Spring Steel| G[Grade 1 or 2]

This

IS 4992: Workmanship - Key Specifications & Sampling

Material Specifications (Clause 1.6):

• Brass Sheet: Min 1.6 mm thick, alloy CuZn 40 (IS: 410-1967)
• Mild Steel Sheet: Min 1.6 mm thick, Grade 0-1079 (IS: 1079-1973), bend test: 180° bend around twice thickness without cracks
• Connecting Rods: Mild steel bar (Tensile strength ≥ 32 kgf/mm², Elongation ≥ 26%) Grade St 32-0 (IS: 1977-1969) or Aluminium extruded rod (Grade 1 or 2, IS: 4454-1967)

Sampling & Acceptance Criteria (Clause 2.1 & Table 2)

• Lot conformity: Lot accepted if defective handles ≤ permissible number.

Bend Test for Mild Steel Sheet

• Bend test: Bend sample 180° around a mandrel twice the thickness.
• No fracture or cracking on the outside.

Summary Diagram: Sampling & Acceptance

flowchart TD
    A[Lot Size] --> B{Select Sample Size}
    B -->|Up to 100| C[Sample 5]
    B -->|101-150| D[Sample 8]
    B -->|151-300| E[Sample 13]
    B -->|301-500| F[Sample 20]
    B -->|501-1000| G[Sample 32]
    B -->|>1000| H[Sample 50]

    C --> I{Defective Handles ≤ 0?}
    D --> J{Defective Handles ≤ 0?}
    E --> K{Defective Handles

IS 4992 - Finish Specifications for Door Handles

Key Finish Requirements (Clause 8.1)

• Brass Handles:
  • Natural finish or bright electro-chromium plating.
• Aluminium Alloy Handles:
  • Anodized finish, quality ≥ Grade AC 10 of IS:1868-1968.
• Zinc Alloy & Mild Steel Handles:
  • Bright chromium plating.

Material & Thickness Requirements (Table 1)

Finish Summary

• Electro-chromium plating for brass and mild steel ensures corrosion resistance and shine.
• Anodizing for aluminum enhances corrosion resistance and surface hardness.
• Thickness and material grades ensure durability and performance.

Reference for Anodizing Quality

• Grade AC 10 as per IS:1868-1968 (Anodic Coating on Aluminium).

Visual Summary of Finish Types

graph TD
    A[Door Handle Material] --> B[Brass]
    A --> C[Al

IS 4992: Sampling and Criteria for Conformity (Appendix A & Table 2)

• Sampling Method: Representative samples are drawn from a lot based on its size.
• Sample Size & Acceptance Criteria: From Table 2:

• Conformity Criteria:
  The lot is conforming if defective handles ≤ permissible number; otherwise, it is non-conforming.

• Additional: Each packing box must include an instruction leaflet about handle use and door type suitability (Clause 11.2).

flowchart TD
    A[Start: Select Lot] --> B{Determine Lot Size}
    B -->|Up to 100| C[Sample 5 Handles]
    B -->|101 to 150| D[Sample 8 Handles]
    B -->|151 to 300| E[Sample 13 Handles]
    B -->|301 to 500| F[Sample 20 Handles]
    B -->|501 to 1000| G[Sample 32 Handles]
    B -->|>1000| H[Sample 50 Handles]
    C --> I{Defective ≤ 0?}
    D --> J{Defective ≤ 0?}
    E --> K{Defective ≤ 0?}
    F --> L{Defective ≤ 1?}
    G --> M{Defective ≤ 2?}
    H --> N{Defective ≤ 3?}
    I --> O[Conforming / Non-conforming]
    J --> O
    K --> O
    L --> O
    M --> O
    N --> O

This ensures quality control by statistically verifying handle conformity per IS 4992.

IS 4992 - Marking for Door Handles (Mortice Locks, Vertical Type)

Key Specifications for Marking:

• Clause 10.1.1:
  Door handles may be marked with the ISI Certification Mark to assure compliance with Indian Standards.

• Purpose of ISI Mark:

  • Confirms production under a strict inspection, testing, and quality control system supervised by ISI.
  • Continuous conformity checks by ISI.

Material & Finish Requirements (Relevant to Marking & Identification):

Summary:

• Marking: ISI mark is optional but recommended for quality assurance.
• Material marking: Manufacturer must certify conformity to IS standards.
• Finish marking: Specified finishes ensure durability and appearance.

flowchart LR
    A[Manufacturer] --> B[Produce Door Handle]
    B --> C[Quality Control & Testing]
    C --> D{Conforms to IS 4992?}
    D -->|Yes| E[Apply ISI Mark (Optional)]
    D -->|No| F[Reject or Rework]
    E --> G[Market with ISI Certification]

This ensures traceability and conformity to Indian Standards for builder's hardware.

IS 4992 - Packing: Key Specifications & Sampling

Packing Requirements (Clause 11.2)

• Each packing box must include an instruction leaflet.
• Leaflet should cover:
  • Use of the door handle.
  • Suitability for the door type.

Sampling & Conformity (Appendix A, Clause 9.1 & Table 2)

• Sampling size depends on lot size.
• Maximum defective handles allowed per sample as above.

Additional Notes

• Handles may vary in shape/dimensions if agreed by manufacturer and purchaser (Clause 5.1.1).
• Test results should be rounded as per IS 2-1960 rounding rules.

This ensures quality control and proper user guidance in packing and sampling of door handles under IS 4992.

IS 4992: Sampling & Criteria for Conformity (Appendix A, Clause 9.1)

Key Points:

• Sampling method: Representative samples drawn per lot size.
• Criteria for conformity: Based on permissible defective handles in the sample.

Table 2: Scale of Sampling & Permissible Defectives

Conformity Criteria:

• Accept lot: Defective handles ≤ permissible number.
• Reject lot: Defective handles > permissible number.

Summary:

• Draw samples as per lot size.
• Check defects in sample.
• Accept/reject lot based on Table 2 limits.

flowchart TD
    A[Start: Identify Lot Size] --> B[Select Sample Size from Table 2]
    B --> C[Inspect Sample for Defects]
    C --> D{Defects ≤ Permissible?}
    D -- Yes --> E[Accept Lot]
    D -- No --> F[Reject Lot]

This ensures quality control aligned with IS 4992 standards.