Specification for indicating bolts for use in public baths and lavatories

IS 4621 - Scope: Key Specifications and Tables

1. Scope Overview

IS 4621 specifies dimensions, tolerances, materials, and workmanship for indicating bolts used in doors.

2. Dimensions and Tolerances (Clause 4.1, Table 1)

• E dimension depends on door thickness.
• Refer to Fig. 1 for letter references.

3. Material Specifications (Clause 5.1, Table 6)

IS 4621: Types of Operations for Indicating Bolts

1. Types of Operations (Clause 2.1)

• Gear Work: Operation is achieved through mechanical gears.
• Displacement: Operation is by direct linear displacement.

2. Key Dimensions & Tolerances (Table 1, Clause 4.1)

Refer to Table 1 for full details.

3. Material Specifications (Clause 5.1)

4. Workmanship & Finish (Clause 7.1)

• Smooth, easy operation.
• Satin finish or bright polished.
• Aluminium bolts anodized to Grade AC 10 per IS: 1868-1968.

flow

IS 4621: Nominal Sizes for Indicating Bolts

1. Nominal Sizes (Clause 3.1)

• Two standard sizes: Size 1 and Size 2
• Custom sizes possible by agreement.

2. Dimensions & Tolerances (Clause 4.1, Table 1)

3. Notes

• Dimensions correspond to Fig. 1 in IS 4621.
• Tolerances ensure interchangeability and proper fit.
• Final measured values should be rounded as per IS 2-1960.

flowchart LR
    A[Nominal Sizes] -->|Size 1| B(Dimensions & Tolerances)
    A -->|Size 2| B
    B --> C[Manufacturing & Quality Control

IS 4621: Dimensions and Tolerances for Indicating Bolts

Key Dimensions & Tolerances (Table 1, Clause 4.1)

• No. of holes: 4 for both sizes
• Door thickness (E): Custom as per installation

Notes:

• Dimensions correspond to typical indicating bolts (Size 1 & 2).
• Tolerances ensure interchangeability and proper fit.
• Refer Fig.1 in IS 4621 for letter references on bolt parts.

Material Specifications (Clause 5.1)

IS 4621: Key Material Specifications for Indicating Bolts

Workmanship & Finish (Clause 7.1)

• Assembled bolts must operate smoothly.
• Finish: Satin or bright polish.
• Aluminium bolts: Anodized to Grade AC 10 as per IS 1868-1968.

Dimensional Tolerances (Excerpt from Table 1)

Refer IS 4621 Fig. 1 for part references.

flowchart TD
    A[Material Selection] --> B[Body, Knob, Spindle]
    A --> C[Indicating Disc]
    A --> D[Gears]
    B -->|Aluminium Alloy Casting| E[IS 617-1959]
    B -->|Brass Casting| F[IS 292

IS 4621 - Manufacture of Indicating Bolts: Key Specifications

1. Material Specifications (Clause 5.1, Table 6)

2. Workmanship and Finish (Clause 7.1)

• Indicating bolts must have smooth and easy operation.
• Finish: Satin or bright polished.
• Aluminium bolts: Anodized finish minimum Grade AC 10 as per IS: 1868-1968.

3. Rounding Off (Clause 0.5)

• Test results must be rounded off as per IS: 2-1960.
• Number of significant figures should match the specified value.

Summary Diagram

flowchart TD
    A[Indicating Bolt Manufacture] --> B[Material Selection]
    B --> C[Body, Knob, Spindle]
    B --> D[Indicating Disc]
    B --> E[Gears]
    C --> F[Aluminium Alloy Casting (IS:617)]
    C --> G[Brass Casting (IS:292)]
    D --> H[Aluminium Sheet (IS:737)]
    D --> I[Brass Casting (IS:

IS 4621: Workmanship and Finish for Indicating Bolts

Key Specifications (Clause 7.1)

• Smooth and easy working of assembled indicating bolts.
• Finish shall be satin finished or bright polished.
• Aluminium bolts must be anodized with finish quality not less than Grade AC 10 as per IS: 1868-1968.

Material Grades (Clause 5.1 - Table 6)

Dimensional Tolerances (Clause 4.1 - Table 1)

IS 4621: Marking, Materials & Dimensions for Indicating Bolts

1. Marking Requirements (Clause 8.1 & 8.1.1)

• Each indicating bolt must bear the manufacturer's name or trade-mark.
• May be marked with the ISI Certification Mark indicating compliance with Indian Standards.
• ISI Mark ensures production under strict inspection, testing, and quality control.

2. Material Specifications (Clause 5.1, Table 6)

• Aluminium bolts must be anodized with finish not less than Grade AC 10 (IS 1868-1968).

3. Dimensions & Tolerances (Clause 4.1, Table 1)

IS 4621 - Packing of Indicating Bolts: Key Points

• Clause 9.1:

  • Bolts must be packed in cartons following usual trade practice.
  • Boxes should be clearly labelled with:
    • Manufacturer's name
    • Trade-mark
    • Quantity details

• Lot Definition (Clause A-1.1):

  • A lot consists of all indicating bolts of the same type, shape, size, and material in a consignment.

• Sampling for Quality Control (Clause A-2.1.1):

  • Samples are randomly selected from at least 10% of packages (minimum 3 packages).
  • Equal number of bolts taken from each selected package.

• Table 3 (Sampling Scale & Defectives):

  • Defines permissible defective limits based on sample size (refer IS 4621 Table 3 for exact values).

Summary Table (Packing & Sampling)

flowchart TD
    A[Manufacture Bolts] --> B[Group by Type/Size/Material (Lot)]
    B --> C[Pack in Cartons]
    C --> D[Label Cartons (Name, Trademark, Qty)]
    D --> E[Random Sampling]
    E --> F{Sample Size}
    F -->|≥10% packages, min 3| G[Select Bolts Equally]
    G --> H[Quality Check per Table 3]

For detailed permissible defectives, refer to Table 3 of IS 4621.

IS 4621: Sampling and Criteria for Conformity (Appendix A)

A-1. Scale of Sampling

A-2. Sampling Procedure

• Samples must be randomly selected from at least 10% of the packages, with a minimum of 3 packages.
• Equal number of bolts to be taken from each selected package.

A-3. Criteria for Conformity

• The lot is accepted if the number of defective bolts in the sample is less than or equal to the permissible number.
• If defects exceed permissible limits, the lot is rejected.

Summary Flowchart

flowchart TD
    A[Define Lot: Same type, shape, size, material] --> B[Determine Lot Size]
    B --> C[Select Sample Size (Table A-2)]
    C --> D[Random Sampling: ≥10% packages, min 3 packages]
    D --> E[Inspect Sample]
    E --> F{Defectives ≤ Permissible?}
    F -- Yes --> G[Accept Lot]
    F -- No --> H[Reject Lot]

This ensures consistent quality control per IS 4621.

IS 4621: Scale of Sampling & Criteria for Conformity (Appendix A)

1. Scale of Sampling (Table A-2)

2. Sampling Procedure

• Randomly select bolts from at least 10% of packages, minimum 3 packages.
• Equal number of bolts from each selected package.

3. Definition of Lot

• All bolts of same type, shape, size, and material in a consignment form one lot.

This ensures statistically valid quality control by limiting defective bolts per sample size.