Specification for sliding locking bolts for use with padlocks
1985 Edition

Overview of Sliding Locking Bolts - Key Specifications & Sampling Details

1. Sampling and Defects (Clause 2.2 & Table 3):

• Lot acceptance depends on defect counts not exceeding limits specified in Table 3.
• Manufacturers must submit test certificates verifying material compliance.

2. Material Criteria (Clause 4.1 & Table 1):

3. Locking Bolt Dimensions (Clause 6.1 & Table 2):

• Standardized length, diameter, width, thickness, and screw hole details.
• Example for Type I, 150 mm size:
  • Bolt plate length: 210 ± 1 mm
  • Bolt length: 150 ± 2 mm
  • Bolt diameter: 10 ± 0.5 mm
  • Bolt plate width: 45 ± 1 mm
  • Bolt plate thickness: 2 ± 0.10 mm

flowchart LR
    A[Batch of Locking Bolts] --> B{Sample Size per Table 3}
    B --> C{Count Defects}
    C -->|≤ Allowed| D[Batch Accepted]
    C -->|> Allowed| E[Batch Rejected]

Scope of the Standard: Formulas, Tables & Specifications

1. Scope Overview (Clause 1.3 & A-1.3)

Defines sampling and acceptance criteria relevant to lots of sliding locking bolts.

2. Sampling Table for Locking Bolts (Table 3)

• Lot acceptance: The defective count must not exceed the allowed number (Clause 2.2).

3. Locking Bolt Dimensions (Table 2, Clause 6.1)

All measurements in millimeters.

IS 7534: Dimensions and Categories of Sliding Locking Bolts

Key Details:

• Available sizes: 110, 150, 200, 250, 300 mm (Clause 3.1)
• Bolt variations:
  • Type I: Straight locking plate (Fig. 1)
  • Type II: Curved locking plate (Fig. 2)

Dimension Summary (from Table 2):

IS 7534: Material Specifications and Manufacturing Details

1. Materials (Clause 4.1 and Table 1)

• Manufacturers must supply test certificates verifying adherence to material standards.

2. Manufacturing (Clause 5.1.2 & 6.1, Table 2)

• Bolts are cut, formed, and fastened via riveting or spot welding near mid-length to restrict excessive movement.
• Bolt plates and bolts conform to specified sizes and tolerances (in millimeters):

3. Quality Assurance

• Compliance of lots is verified based on permissible defect limits specified in Table 3 (Clause 2.2).

IS 7534: Dimensional Specifications and Tolerances for Sliding Locking Bolts

Key Data (Clause 6.1 & Table 2)

Materials (Clause 5.1.2)

• Bolts are fabricated from mild steel or aluminium alloy rods.
• Process involves cutting, bending, and securing via riveting or spot welding at mid-length to limit movement.

Notes on Tolerances

• Minimum edge distance for holes is 5 mm.
• All sizes are expressed in millimeters.
• Aluminium components are generally thicker by 1 mm compared to mild steel for enhanced strength.

Visual Summary

flowchart LR
    A[Locking Bolt] --> B(Bolt Plate Length A)
    A --> C(Bolt Length B)
    A --> D(Bolt Diameter D)
    A --> E(Bolt Plate Width E)
    A --> F(Bolt Plate Thickness T1)
    A --> G(Plate Thickness Carrying Bolt Ta)

IS 7534: Surface Treatment and Finishing Requirements

Materials and Treatments (Clause 4.1 & 8.1)

• Bolt Plate & Receiving Plate:
  • Mild Steel Sheet: IS 1079-1973 (Grade 0-1079)
  • Aluminium Alloy Sheet: IS 737-1974 (Designations 52000 or 65032)
• Bolts:
  • Mild Steel Rods: IS 1977-1975 (Grade Fe 310-0)
  • Aluminium Alloy Extruded Rods: IS 733-1983 (Designations 63400 WP or 65032 WP)
• Markings: Each locking bolt must display the manufacturer’s name or trademark.

Surface Finishing

• Aluminium parts may be treated with anodic coatings per IS anodic coatings specification (second revision) to boost corrosion resistance.

Material Grades Summary

Additional Notes:

• Surface finishing must provide durability and resistance against corrosion.
• Screws conform to IS 6760-1972 (slotted countersunk head wood screws).
• Test certificates for material compliance are mandatory from manufacturers.

graph TD
    A[Raw Materials] --> B{Material Type}
    B -->|Mild Steel| C[IS 1079-1973 / IS 1977-1975]
    B -->|Aluminium Alloy| D[IS 737-1974 / IS 733-1983]
    C --> E[Manufacture Bolt & Plates]
    D --> E
    E --> F[Surface Treatment]
    F --> G[Manufacturer Identification Marking]

This ensures compliance with IS 7534 for quality and longevity.

IS 7534 - Marking: Essential Guidelines

Marking Requirements (Clause 8.1):

• Each sliding locking bolt must have the manufacturer’s name or trademark clearly marked.
• Locking bolts can optionally carry the ISI Certification Mark (Clause 8.1.1), indicating conformity to Indian Standards under ISI governance.

Sampling and Compliance (Clause 2.2 & 9)

• A batch is deemed compliant if defectives in the sampled lot do not exceed the allowable count specified in Table 3.
• Material conformity must be supported by a test certificate from the manufacturer.

Dimensional Details (Table 2, Clause 6.1)

IS 7534: Sampling Methods and Acceptance Standards

1. Sampling Sizes (Table 3, Clause A-1.3)

2. Acceptance Rules (Clause A-2.2)

• A lot qualifies if the defectives counted in the sample are at or below the permissible limit from Table 3.
• Material compliance must be backed by a test certificate (Clause 4).

3. Sampling Technique (Clause A-1.2 & 9.1)

• Samples are taken individually from each lot.
• Test results are rounded as per IS 2-1960 and maintain specified significant digits.

Summary:

• Sampling size and acceptance limits vary by lot size.
• Zero defects permitted for small batches (≤ 150).
• Permissible defects increase with lot size, capped at 3.

flowchart TD
    A[Batch of Locking Bolts] --> B[Select Sample per Table 3]
    B --> C[Perform Testing]
    C --> D{Are Defectives ≤ Allowed?}
    D -- Yes --> E[Batch Accepted]
    D -- No --> F[Batch Rejected]

This statistical approach ensures quality control compliance.

IS 7534: Sampling Protocols and Quality Assurance Procedures

1. Sampling Scale and Tolerance for Defectives (Table 3)

2. Acceptance Criteria (Clause A-2.2)

• A lot is accepted if the number of defectives in the sample does not exceed the permitted number per Table 3.
• Test certificates confirming material compliance must be presented by the manufacturer.

3. Procedures for Sampling and Testing

• Sampling is performed on each lot independently (Clause A-1.2).
• Results must be rounded according to IS 2-1960, preserving the same number of significant figures as called for.

Summary Flow

flowchart TD
    A[Start: Identify Lot Size] --> B{Lot Size}
    B -->|≤150| C[Sample 13 Bolts]
    B -->|151-300| D[Sample 20 Bolts]
    B -->|301-500| E[Sample 32 Bolts]
    B -->|>500| F[Sample 50 Bolts]
    C --> G[Count Defectives]
    D --> G
    E --> G
    F --> G
    G --> H{Defectives ≤ Allowed?}
    H -->|Yes| I[Accept Lot]
    H -->|No| J[Reject Lot]

This method guarantees statistically valid quality control as per IS 7534.