metal paper trays - Specification

IS 3791: Scope & Key Specifications Summary

• Scope: Covers technical requirements for metal paper trays, including materials, welding, and fabrication details.

• Purchaser's Role: Clause 0.3 mandates supplying technical info at order placement (see Clause 9).

• Welding Standards (Clause 5.2):

  • Gas, arc, and spot welding must conform to:
    • IS 1323-1966T (Wrought aluminium & alloys)
    • IS 816-1969 (Structural steel welding)
    • IS 819-1957 (Covered electrodes for metal arc welding)
    • IS 2812-1964 (Oxy-acetylene welding practice)

• Rounding Off Results: As per IS 2-1960, test/analysis values must be rounded to match the precision of specified values (Clause 0.5).

• Material Specifications: Refer to relevant IS codes for steel sheets (hot-rolled, cold-rolled), aluminium alloys, and filler materials.

Important Reference Table (Welding Codes)

Note: This standard aligns with international practices and Indian conditions for structural steel and aluminium fabrication.

IS 3791: Key Materials Specifications & References

• Mild Steel Sheets:

  • Grade 0 of IS 1079-1973 or IS 513-1973 (Clause 2.3)
  • Thickness example: 0.315 mm (for pressure tests, Clause 8.2)

• Aluminium Sheets:

  • Conform to H condition, 19000 quality of IS 737-1974 (Clause 2.1)

• Welding Standards (Clause 5.2):

  • Gas, arc, spot welding methods per IS 1323-1966T, IS 816-1969, IS 819-1957, IS 2812-1964
  • Includes specifications for filler rods, electrodes, and welding practices for mild steel and aluminium alloys

• Surface Treatment & Paints:

  • Phosphate treatment: IS 101-1964 and relevant codes for corrosion protection
  • Ready mixed paints and enamels for primers and finishing as per IS standards cited

Typical Pressure Test for Mild Steel Sheets (Clause 8.2)

Welding Reference Summary

flowchart TD
    A[Materials] --> B[Mild Steel Sheets]
    A --> C[Aluminium Sheets]
    A --> D[Welding Methods]
    A --> E[Surface Treatment & Paints]

    B --> B1[IS 1079-1973 / IS 513-1973]
    C --> C1[IS 737-1974]
    D --> D1[IS 1323, IS 816, IS 819, IS 

IS 3791: Dimensions and Tolerances Summary

Key Specifications:

• Overall Dimension Tolerance: ± 5 mm (Clause 3.2)
• Material: Mild steel sheets conforming to:
  • IS 1079-1973 Grade 0 (Hot rolled carbon steel sheet and strip)
  • IS 513-1973 Grade 0 (Cold rolled carbon steel sheets) (Clause 2.3)

Welding Standards (Clause 5.2):

• Gas welding: IS 1323-1966T
• Arc welding: IS 816-1969
• Spot welding: IS 819-1957 and IS 2812-1964

Dimensions:

• All dimensions are in millimetres.
• Refer to Fig. 1 (Metal Paper Tray) for detailed dimensional layout and knife edge details.

Summary Table: Dimension Tolerances

Notes:

• Use proper welding methods as per referenced IS codes for structural integrity.
• Material selection per IS 1079 or IS 513 ensures conformity to mechanical properties.

flowchart LR
    A[Material: Mild Steel Sheets] --> B[Dimensions Specified]
    B --> C[Tolerance ±5 mm]
    B --> D[Welding Methods]
    D --> E[Gas Welding (IS 1323)]
    D --> F[Arc Welding (IS 816)]
    D --> G[Spot Welding (IS 819, IS 2812)]
    C --> H[Final Product: Metal Paper Tray]

This concise overview ensures compliance with IS 3791 for dimensions and tolerances in metal paper trays.

IS 3791 – Construction Key Points

Welding Methods (Clause 5.2)

• Welding must follow:
  • Gas welding: IS 1323-1966T
  • Metal arc welding: IS 816-1969, IS 819-1957
  • Spot welding: IS 2812-1964
• Additional codes for welding aluminium alloys and mild steel are referenced.

Material Specifications

• Mild Steel Sheets: Grade 0 as per IS 1079-1973 or IS 513-1973 (Clause 2.3)
• Aluminium and alloys: Wrought sheets and strips for engineering.
• Filler rods, electrodes, and welding wires must conform to respective IS standards.

Dimensions & Tolerances (Clause 3)

• All dimensions in millimeters.
• Example: Mild steel panel for corrosion test - 150 x 100 mm, 1.25 mm thick (Clause 8.5).

Tests

• Corrosion Protection: Panel tested as per IS 101-1964, no corrosion after condensation test.
• Pressure Test: Samples of 0.315 mm thickness tested per IS 101-1964, no visible metal surface after test (Clause 8.2).

Summary Table: Mild Steel Sheet Requirements

Welding Process Flow (Mermaid Diagram):

flowchart TD
    A[Start: Material Selection] --> B[Check Material Grade]
    B --> C{Welding Type}
    C -->|Gas Welding| D[Follow IS 1323-1966T]
    C -->|Arc Welding| E[Follow IS 816-1969 & IS 819-1957]
    C -->|Spot Welding| F[Follow IS 2812-1964]
    D & E & F --> G[Perform Welding]
    G --> H[Conduct

Assembly and Welding per IS 3791

Key References:

• Welding methods must comply with:
  • IS 1323-1966 (Gas welding)
  • IS 816-1969 (General structural welding)
  • IS 819-1957 (Metal arc welding)
  • IS 2812-1964 (Oxy-acetylene welding for structural mild steel)
• Electrodes per IS 1278-1972 and IS 814 (Part 2)-1974
• Mild steel sheets per IS 1079-1973 or IS 513-1973

Welding Specifications:

Assembly Details (Clause 5.1)

• Sides and bottom of assemblies shall be joined by welding.
• Use knife edge joint details as per Fig. 1 (dimensions in mm).

Electrodes and Materials:

• Electrodes for gas and arc welding must conform to IS standards.
• Mild steel sheets should be Grade 0 as per IS 1079 or IS 513.

Summary Formula for Weld Size (General Practice):

For fillet welds, the throat thickness (t) is:

[ t = 0.7 \times \text{leg size} ]

Ensure weld sizes meet strength requirements per IS 816.

flowchart LR
    A[Start: Assembly] --> B[Select Welding Method]
    B -->|Gas Welding| C[IS 1323]
    B -->|Arc Welding| D[IS 819]
    B -->|Oxy-Acetylene| E[IS 2812]
    B -->|Spot Welding| F[Resistance Spot Code]
    C & D & E & F --> G[Use Electrodes per IS 1278 & IS 814]
    G --> H[As

IS 3791: Additional Accessories - Key Specifications & References

Clause 6.1: Additional Accessories

• Spring Clip: A spring clip may be fitted inside the paper tray on a shorter side to hold papers, if specified by the purchaser.

Welding Methods (Clause 5.2)

Welding must conform to these IS standards:

Corrosion Protection Test (Clause 8.5)

• Test Panel: Mild steel, 150 x 100 mm, thickness 1.25 mm
• Finish: As per Clause 7
• Test Method: IS 101-1964, Clause 18 (Condensation corrosion test)
• Acceptance: No corrosion signs after test

Summary Diagram: Additional Accessory Integration

flowchart LR
    A[Paper Tray] --> B[Spring Clip (Optional)]
    B --> C[Holds Papers Securely]
    A --> D[Steel Panel (150x100x1.25mm)]
    D --> E[Corrosion Test per IS 101-1964]
    E --> F[No Corrosion Allowed]

For ordering, purchaser must specify if spring clip is required and provide technical details as per Clause 9.

IS 3791: Surface Preparation and Finishing - Key Points

Surface Preparation

• Phosphating Treatment:
  • All mild steel parts must be phosphated immediately after pickling.
  • Conforms to Grade C of IS 3618-1966.
  • Application process as per IS 6005-1970 (Code of practice for phosphating).

Finishing Specifications

• Finish Quality (Clause 7.3.1):

  • Smooth, uniform, defect-free finish.
  • Hard, resistant to chipping/flaking.
  • Dry film thickness ≥ 0.10 mm.

• Putty and Primers:

  • Putty per IS 110-1968 for surface filling.
  • Aluminium primer per IS 5660-1970.

Testing Requirements

• Pressure Test (Clause 8.2):

  • Samples from 0.315 mm mild steel plates, finished as per Clause 7.
  • Pressure test per IS 101-1964, Clause 15.2.
  • No visible metal surface after test separation.

• Corrosion Protection Test (Clause 8.5):

  • Mild steel panel 150x100 mm, thickness 1.25 mm.
  • Tested under condensation per IS 101-1964, Clause 18.
  • No corrosion signs allowed post-test.

Summary Table

IS 3791: Performance Requirements of Finish

Key Specifications (Clause 7.3.1 & 8)

• Finish Quality: Smooth, uniform, free from visible defects.
• Hardness: Shall be hard, not readily chip or flake.
• Dry Film Thickness: Minimum 0.10 mm.

Performance Tests (Clause 8)

Purchaser's Information (Clause 9.1)

• Colour and finish details.
• Alternative construction/finish methods if any.

Summary Table of Finish Requirements

flowchart LR
    A[Finish Application] --> B[Dry Film Thickness ≥ 0.10 mm]
    B --> C{Quality Checks}
    C --> D[Smooth & Uniform Surface]
    C --> E[Hardness Test - No Chipping]
    C --> F[Pressure Test - IS 101:1964]
    C --> G[Condensation Corrosion Test - IS 101:1964]
    D & E & F & G --> H[Acceptable Finish]

This ensures durable, corrosion-resistant, and visually acceptable finishes on mild steel surfaces per IS 3791.

IS 3791 - Information to be Supplied by the Purchaser (Clause 9.1)

When placing an order, the purchaser must provide:

• Colour and finish of the metal product.
• Specification of alternative methods of construction and finish, if any options exist.

Related Specifications & Tests

• Corrosion Protection Test (Clause 8.5):
  A mild steel panel (150 mm x 100 mm x 1.25 mm) finished per Clause 7 must pass condensation corrosion test as per IS 101:1964 (Clause 18). No corrosion should appear post-test.

• Welding Methods (Clause 5.2):
  Welding must conform to relevant IS codes:

  • Gas welding: IS 1323-1966T
  • Arc welding: IS 816-1969
  • Spot welding: IS 819-1957, IS 2812-1964

Summary Table: Purchaser's Information Checklist

flowchart TD
    A[Purchaser places order] --> B{Information to supply}
    B --> C[Colour and Finish]
    B --> D[Alternative Construction Method]
    B --> E[Welding Method per IS codes]
    B --> F[Corrosion Protection Requirements]

Note: Clear communication of these details ensures compliance with IS 3791 and quality assurance of metal products.

IS 3791: Marking of Metal Paper Trays (Clause 10.1 & 10.1.1)

• Mandatory Marking: All metal paper trays shall be marked with a suitable mark identifying the manufacturer (Clause 10.1).
• ISI Certification Mark: May also bear the ISI Certification Mark indicating compliance with the Indian Standard under ISI quality control and inspection (Clause 10.1.1).
• Legal Use: Use of ISI mark is governed by the Indian Standards Institution (Certification Marks) Act and requires a license from ISI.

Summary Table for Marking Requirements

Notes:

• Marking ensures traceability and quality assurance.
• ISI mark assures continuous conformity checks by ISI.
• For licensing details, contact the Indian Standards Institution.

flowchart LR
    A[Manufacturer] --> B[Mark Metal Paper Tray]
    B --> C{Use ISI Mark?}
    C -->|Yes| D[Obtain ISI License]
    C -->|No| E[Only Manufacturer's Mark]
    D --> F[Apply ISI Certification Mark]
    E --> F

This ensures product identification and quality assurance per IS 3791.