metal folding chairs - Specification

IS 3763: Scope & Key Specifications Summary

Scope:

• Covers metal folding chairs with emphasis on quality, safety, and marking.
• Includes requirements for materials, fabrication, and finishing.
• Specifies caps for chair legs to prevent floor marking and sliding (Clause 3.2.1).
• Requires purchaser to provide technical info when ordering (Clause 0.3).

Marking (Clause 10.1.1):

• Chairs may bear the ISI Certification Mark ensuring compliance with ISI inspection and quality control.
• ISI mark use governed by Indian Standards Institution (Certification Marks) Act.

Units & Definitions:

• Uses SI units for all measurements.
• Key units include:
  • Length: metre (m)
  • Mass: kilogram (kg)
  • Force: newton (N) = kg·m/s²
  • Pressure/stress: pascal (Pa) = N/m²
  • Energy: joule (J) = N·m
  • Power: watt (W) = J/s

Material & Fabrication:

• Bottom ends of chair legs must have caps (metal/plastic/rubber) to protect floors and resist sliding.
• Caps must be fabricated to minimize cutting/shearing during use.

Important Formulae & Units

Summary Diagram: Chair Leg End Protection

graph LR
A[Chair Leg Bottom End] --> B[Cap Material]
B --> C[Metal]
B --> D[Plastic]
B --> E[Rubber]
C & D & E --> F[Prevents Floor Marking & Sliding]
F --> G[Minimize Cutting/Shearing]

For detailed technical requirements, refer to IS 3763 clauses on materials, fabrication, and testing.

IS 3763 - Key Material Specifications & Relevant Formulas

1. Materials for Tubes & Caps (Clause 3.2.1)

• Tube ends: Bottom ends of chair legs may have caps made of metal, plastic, rubber, or resilient materials.
• Caps must not mark floors and resist sliding.
• Caps and tube ends should be fabricated to minimize cutting/shearing during use.
• Rear leg top ends may also be plugged with similar caps.

2. Steel Sheets

• Mild steel sheets shall conform to:
  • IS 1513-1973 (Grade O)
  • IS 1079-1973 (Grade O)

3. Welding Materials

• Filler rods and wires for gas welding (2nd revision).
• Covered electrodes for metal arc welding of structural steel (Part 1, 4th revision).

4. Paint & Coating Tests

• Flexibility and adhesion test on mild steel plate (150×50 mm, thickness 0.315 mm) per IS 101-1964.
• Paint film must show no damage or cracking under 10x magnification.

5. Units & Definitions

Summary Table: Material Specifications

flowchart TD
    A[Chair

IS 3763: Components and Construction of Metal Folding Chairs

Key Specifications:

• Clause 3.1: Chairs are assembled from components per Clauses 3.2 to 3.5.
• Clause 3.2.1 (Ends of Tubes):
  • Bottom ends of chair legs may have caps (metal, plastic, rubber) that:
    • Do not mark floors
    • Resist sliding
    • Minimize cutting/shearing during use
  • Top ends of rear legs may be plugged or capped similarly.

Materials & Welding:

• Use filler rods/wires for gas welding as per relevant IS specifications.
• Covered electrodes for metal arc welding of structural steel per IS standards.
• Steel tubes for furniture must conform to IS specifications.
• Cold-rolled and hot-rolled carbon steel sheets/strips per IS standards.

Marking (Clause 10.1.1):

• Chairs may bear ISI Certification Mark ensuring compliance with quality and production standards.

Important Units & Definitions (SI Units relevant to construction):

Summary Diagram of Tube End Caps:

graph LR
A[Tube End] --> B[Bottom End Cap]
A --> C[Top End Cap (Rear Legs)]
B --> D[Materials: Metal, Plastic, Rubber]
C --> D
D --> E[Properties: Non-marking, Sliding Resistant, Durable]

Note: For detailed dimensions, welding parameters, and material grades, refer to the specific IS codes mentioned (e.g., IS for steel tubes, welding electrodes).

Assembly Methods in IS 3763 (Key Points)

Clause 4.2:

• Assembly of metal folding chairs is done by riveting, bolting, or welding.

Specifications & Related Standards

Tube End Caps (Clause 3.2.1)

• Bottom ends: Metal/plastic/rubber caps to avoid floor marking and sliding.
• Caps must be fabricated to minimize cutting/shearing during use.
• Top ends (rear legs): May be plugged or capped similarly.

Summary Diagram of Assembly Methods

graph LR
A[Chair Components] --> B[Riveting]
A --> C[Bolting]
A --> D[Welding]
D --> D1[Arc Welding (IS 814, IS 10232)]
D --> D2[Gas Welding (IS 816)]
D --> D3[Resistance Spot Welding (IS 11239)]
D --> D4[TIG Welding (IS 13354)]

For detailed welding parameters, refer to the respective IS codes mentioned. Use appropriate filler materials and electrode types per IS 814 and IS 816 for steel, and IS 13354 for aluminium.

IS 3763: Dimensions and Tolerances for Metal Folding Chairs

Key Specifications:

• Overall Dimensions Tolerance: ±5 mm (Clause 5.3)
• Units: All dimensions in millimeters (mm)
• Dimension Reference: As per Clause 5.1 (detailed chair dimensions in 5.1.1 to 5.1.3)
• Tube Ends: Bottom ends may have caps (metal/plastic/rubber) to avoid floor marking and sliding (Clause 3.2.1)

Summary Table for Dimensions & Tolerances

Notes:

• Dimensions must be rounded off as per IS rounding rules.
• Caps should minimize damage during usage.
• Detailed chair dimensions (seat height, width, backrest height) are specified in Clause 5.1.1 to 5.1.3 (refer IS 3763 for exact values).

flowchart LR
    A[Chair Dimensions] --> B[Overall dimension ±5 mm tolerance]
    A --> C[Tube Ends]
    C --> D[Bottom caps: metal/plastic/rubber]
    C --> E[Top rear leg ends capped]
    B --> F[Dimensions in mm]

For exact dimension values, refer to Clause 5.1.1 to 5.1.3 of IS 3763.

IS 3763: Finish and Corrosion Protection - Key Points

1. Phosphating Treatment

• Standard: Phosphating as per IS 3618-1966 (Class C)
• Application: According to IS 6005-1970
• Purpose: Provides corrosion resistance by forming a protective phosphate layer on mild steel.

2. Paint & Primer Specifications

• Aluminium Red Oxide Primer: IS 5660-1970
• Putty (Filler): IS 110-1968
• Ready Mixed Paints & Enamels: Various IS codes for brushing, spraying, stoving, and finishing coats.

3. Tests for Finish Quality

• Flexibility and Adhesion Test (Clause 7.3):

  • Sample size: 150 × 50 mm, thickness 0.315 mm
  • No paint film damage or detachment under 10× magnification after bending (IS 101-1964, Clause 16).

• Corrosion Protection Test (Clause 7.5):

  • Sample size: 150 × 100 mm, thickness 1.25 mm
  • No corrosion after condensation test (IS 101-1964, Clause 18).

Summary Table: Finish Requirements

flowchart TD
    A[Steel Part]

IS 3763: Testing Requirements - Key Points & Specifications

1. Rounding Off Test Results

• Final test or analysis values must be rounded as per IS 2-1960.
• Retain the same number of significant digits as the specified standard value.

2. Flexibility and Adhesion Test (Clause 7.3)

• Sample: Mild steel plate 150 × 50 mm, thickness 0.315 mm.
• Test per IS 101-1964, Clause 16.
• Paint film must show no damage, detachment, or cracking under ×10 magnification.

3. Marking (Clause 10.1.1)

• Metal folding chairs may carry the ISI Certification Mark, ensuring compliance and continuous quality checks.

4. Units and Symbols (SI Units)

Summary Table: Flexibility and Adhesion Test Sample Size

flowchart TD
    A[Test Sample: Mild Steel Plate] --> B[Size: 150x50 mm, Thickness: 0.315 mm]
    B --> C[Apply Paint as per Clause 6]
    C --> D[Perform Flexibility & Adhesion Test (IS 101-1964)]
    D --> E{Examine under ×10 magnification}
    E -->|No damage/cracking| F[Pass]
    E -->|Damage/cracking| G[Fail]

Note: For detailed test procedures, refer to IS 101-

IS 3763: Information to be Supplied by the Purchaser

Per IS 3763, the purchaser must provide the following key information when placing an order:

• Colour and Finish: Specify the exact colour and type of finish required.
• Alternative Methods: If multiple construction or finishing methods are acceptable, clearly state the preferred option(s).
• Corrosion Protection Test: For mild steel panels (150 x 100 mm, 1.25 mm thick), confirm compliance with IS 101-1964 test for corrosion under condensation.
• Marking Requirements: Indicate if ISI Certification Marking is required on metal folding chairs as per Clause 10.1.1.

Summary Table: Information to be Supplied by Purchaser

Notes on Units and Testing (from IS 3763):

• Corrosion test panel size: 150 mm x 100 mm x 1.25 mm thickness
• Test standard: IS 101-1964
• No signs of corrosion allowed post-test.

This ensures clarity in order specifications, quality control, and compliance with IS standards.

IS 3763 - Packaging Specifications for Metal Folding Chairs

• Clause 9.1:
  All component parts must be packed to prevent damage during transit.

• Clause 3.2.1 (related to tube ends):

  • Bottom ends of chair legs should have caps (metal/plastic/rubber) that:
    • Do not mark floors
    • Resist sliding
    • Minimize cutting/shearing during use
  • Top ends of rear legs may be plugged or covered similarly.

• Marking (Clause 10.1.1):
  Chairs may carry the ISI Certification Mark, ensuring compliance with quality and inspection standards.

Packaging Best Practices Summary:

Additional Notes:

• Packaging should ensure mechanical protection and ease of handling.
• Use resilient materials for end caps to protect both chair and floor.
• Follow ISI guidelines for quality assurance and marking.

flowchart TD
    A[Component Parts] --> B[Packaging]
    B --> C{Damage Prevention}
    C --> D[Use protective caps on tube ends]
    C --> E[Secure packing to avoid movement]
    B --> F[Marking]
    F --> G[ISI Certification Mark]

This ensures safe delivery and compliance with IS 3763.

IS 3763 - Marking of Metal Folding Chairs (Clause 10.1 & 10.1.1)

• Mandatory Marking:
  All metal folding chairs shall be marked with a suitable mark identifying the manufacturer (Clause 10.1).

• Optional ISI Certification Mark:
  Chairs may also be marked with the ISI Certification Mark (Clause 10.1.1), indicating compliance with IS standards and quality control under ISI supervision.

Key Points on ISI Certification Mark:

• Governed by the Indian Standards Institution (Certification Marks) Act.
• Signifies products conform to the standard through continuous inspection and testing.
• License for use is granted by ISI under specific conditions.

Summary Table for Marking Requirements

Additional Relevant Note:

• End caps on chair legs (metal/plastic/rubber) must prevent floor marking and resist sliding (Clause 3.2.1).

If you need detailed marking layout or dimensions, IS 3763 does not specify exact formats—manufacturer discretion applies, ensuring clear identification and traceability.

flowchart TD
    A[Metal Folding Chair] --> B[Manufacturer's Mark (Mandatory)]
    A --> C[ISI Certification Mark (Optional)]
    B --> D[Identification & Traceability]
    C --> E[Quality Assurance by ISI]

References: IS 3763 Clauses 10.1, 10.1.1; Indian Standards Institution Certification Marks Act.