Specification for hot-rolled steel sections for doors, windows and ventilators

IS 7452 - Scope & Key Specifications Summary

• Scope: Covers hot rolled steel sections with specified dimensional tolerances and mass per unit length.

1. Dimensional Tolerances (Clause 6.2.1 & Table 6.2.3)

• These tolerances apply to dimensions not covered under Clauses 6.2.1 and 6.2.2.
• All dimensions are in millimeters.

2. Mass per Unit Length (Clause 2.30)

• Mass = 2.30 kg/m for K12B section (example).
• Mass values must be rounded as per IS 2:1960 rules (round off numerical values maintaining significant digits).

3. Rounding Off (Clause None)

• Final test or analysis results should be rounded according to IS 2:1960.
• Retain the same number of significant digits as the specified value.

Visual: Dimensional Tolerances Overview

flowchart LR
    A[Dimension (mm)] --> B{Tolerance (mm)}
    B -->|≤10| C[±0.2]
    B -->|>10 and ≤25| D[±0.4]
    B -->|>25| E[±0.6]

This ensures uniformity in manufacturing and quality control of hot rolled steel sections per IS 7452.

Referenced Indian Standards in IS 7452

IS 7452 refers to several key Indian Standards essential for compliance:

Additional Specifications

• Marking (Clause 11.1): Sections must be indelibly marked every 1 meter with manufacturer identification.
• Rounding Off (IS 2:1960): Test results must be rounded off per IS 2 rules, maintaining the same significant figures as specified values.

Usage of Sections (Annex A)

Sections are designated for specific uses such as:

• T2, T3: Vertical/horizontal glazing bars for doors, windows, ventilators.
• F500-F502: Inner/outer frames for open-out windows, bottom-hung ventilators.
• K11B, K12B: Vertical/horizontal coupling mullions, weather bars for windows exposed to rain.

Summary Diagram of Section Usage

graph TD
  A[Sections] --> B[T2, T3: Glazing Bars]
  A --> C[F500-F502: Frames for Windows/Ventilators]
  A --> D[K11B, K12B: Coupling Mullions & Weather Bars]
  B --> E[Doors, Sashes, Windows]
  C --> F[Open-out Windows, Bottom-hung Ventilators]
  D --> G[Standard Windows, Rain-exposed Units]

For detailed design, testing, and marking requirements, always refer to the full IS 7452 and related IS codes listed above.

IS 7452: Terminology & Definitions for Steel Doors, Windows, Ventilators

Key Terminology (Clause 3.1 & Fig. 1)

• Overall Height of Door/Window/Sub-light: Total vertical dimension including frame.
• Overall Width of Door/Window/Side-light: Total horizontal dimension including frame.
• Sub-dividing Bars: Bars dividing fixed lights or glazing units.
• Sash Bars: Bars in operable parts (sashes) of doors/windows.
• Mullions: Vertical bars dividing window units.
• Transoms: Horizontal bars dividing window units.

Section Designations & Uses (Annex A)

Dimensional Tolerances (Clause 6.2.1)

Rounding Off (Clause 3.1)

• Follow IS 2:1960 rules.
• Retain significant figures equal to the specified value.

Visual Summary of Terminology (Simplified)

graph TD
  A[Door/Window Unit] --> B[Overall Height]
  A --> C[Overall Width]
  A --> D[Sub-dividing Bars]
  A --> E[Sash Bars]
  A --> F[Mullions (Vertical)]
  A --> G[Transoms (Horizontal)]

Note: For detailed section profiles and exact dimensions, refer to IS 7452 Annex A tables.

IS 7452: Designation and Profiles of Hot Rolled Steel Sections

Key Points from IS 7452:

• Designation (Clause 4.1):
  Hot rolled steel sections are designated by specific letters as per profiles shown in Fig. 2 (e.g., I, H, T, L sections).

• Mass per unit length (Clauses 2.28, 2.250, 2.30):
  Mass values are given for different profiles, e.g.,

  • 2.28 kg/m for F4B section
  • 1.419 kg/m for F7D section
  • 2.250 kg/m for F501 section
  • 2.30 kg/m for K12B section
    These help in quick weight estimation and design calculations.

• Dimensions:
  All dimensions are in millimeters and include flange width, thickness, web thickness, and radii (except where max radii specified).

Typical Profile Designation Example:

Formula for Mass per unit length (approximate):

[ \text{Mass (kg/m)} = \text{Cross-sectional Area (cm}^2) \times 7.85 \times 10^{-2} ]

Where 7.85 g/cm³ is density of steel.

flowchart LR
    A[Hot Rolled Steel Sections] --> B{Designation Letters}
    B --> C[I-Section]
    B --> D[Channel]
    B --> E[Angle]
    A --> F[Mass per unit length]
    F --> G[Use in weight calculation]
    A --> H[Dimensions in mm]

Summary: IS 7452 provides standardized profiles with designated letters, mass per meter values, and dimensional details for hot rolled steel sections, facilitating uniform design and specification.

IS 7452: Material Requirements - Key Formulas & Specifications

• Mass per meter (kg/m) is a primary material property given for hot rolled steel sections.
• Mass values are specified for different profiles (e.g., F4B, F7D, K12B) in Clause 2.28, 2.30, 2.250, 1.90.
• All dimensions and mass values are in millimeters (mm) and kilograms per meter (kg/m) respectively.
• Typical mass values from the code:

  Profile	Mass (kg/m)
  F4B	2.28
  F7D	1.419
  K12B	2.30
  F501	2.250
  EZ7	1.90

General Formula for Mass of Steel Section

If dimensions are known, mass can be calculated as:

[ \text{Mass (kg/m)} = \text{Cross-sectional Area (mm}^2) \times \frac{\rho}{10^6} ]

where (\rho = 7850 , \text{kg/m}^3) (density of steel).

Notes:

• Mass values help in estimating material quantity and weight for structural design.
• Refer to Figure 2 in IS 7452 for detailed profiles and dimensions of hot rolled sections.
• Radii and other geometric details are specified per profile and must be checked for fabrication accuracy.

flowchart LR
A[Profile Type] --> B[Dimensions (mm)]
B --> C[Cross-sectional Area]
C --> D[Calculate Mass using density]
D --> E[Material Weight (kg/m)]

This ensures precise material estimation and compliance with IS 7452 standards.

IS 7452: Dimensions and Dimensional Tolerances Summary

1. Measurement Method (Clause 6.1.1)

• Measure dimensions at two ends (leaving 150 mm from each end) and at the center.
• Take the average of three readings.
• Record measurements to the nearest 0.1 mm.

2. Dimensional Tolerances (Clause 6.2.1 & Table 6.2.3)

3. Special Tolerance (Clause 6.2.3.1)

• Dimensions of matching portions (marked with *) in Fig. 2 must be within ± 0.4 mm.

Key Notes:

• Tolerances apply to rolling dimensions except those specifically covered in Clauses 6.2.1 & 6.2.2.
• Ensures dimensional consistency for steel rolled sections.

flowchart LR
    A[Measure at two ends (leave 150 mm)] --> B[Measure at center]
    B --> C[Take average of 3 readings]
    C --> D[Compare with tolerance]
    D -->|Within tolerance| E[Accept section]
    D -->|Outside tolerance| F[Reject section]

This ensures quality control in steel section dimensions per IS 7452.

IS 7452: Mass and Mass Tolerance Key Points

Mass Tolerance (Clause 7.2):

• The mass tolerance per meter length of steel sections is ±5% of the nominal mass.

Mass Calculation (Clause 1.14):

• Mass is given in kg/m for various profiles, e.g.,
  • Mass = 1.14 kg/m (T3 profile)
  • Mass = 0.839 kg/m (another profile)
  • Mass = 1.46 kg/m (F2 profile)

Dimensional Tolerances (Clause 6.2):

• Flanges must be parallel for proper matching (6.2.3.2).
• All dimensions are in millimeters.

Formula for Mass Tolerance

[ \text{Mass tolerance} = \pm 5% \times \text{Nominal mass (kg/m)} ]

Example Table of Mass and Tolerance

Summary

• Check nominal mass from IS 7452 tables for the profile.
• Apply ±5% tolerance for acceptable mass variation.
• Ensure dimensional tolerances, especially flange parallelism, for fit and function.

flowchart LR
    A[Nominal Mass (kg/m)] --> B[Calculate ±5% Tolerance]
    B --> C[Mass Range = Nominal ± Tolerance]
    C --> D[Check Mass During Quality Control]

IS 7452: Surface Finish and Quality Requirements

1. Mass Tolerance (Clause 7.2)

• Mass tolerance per meter length = ± 5% of nominal mass for the section.

2. Dimensional Tolerances (Clause 6.2)

• Matching portions (marked with *) in Fig. 2 must be within ± 0.4 mm.
• Final test results should be rounded as per IS 2:1960 rounding rules, maintaining the same significant figures as specified.

3. Surface Finish (Clause 8)

• The code emphasizes adherence to dimensional tolerances and mass tolerance to ensure surface quality.
• Surface finish requirements are indirectly controlled by maintaining strict dimensional and mass tolerances.

Summary Table for Tolerances

Notes:

• Surface finish quality is indirectly ensured by controlling dimensional accuracy and mass uniformity.
• For detailed surface roughness parameters, refer to specific product or application standards.

flowchart LR
    A[Nominal Section Mass] --> B[Mass Tolerance ±5%]
    C[Dimensions of Matching Portion] --> D[Dimensional Tolerance ±0.4 mm]
    E[Measured Values] --> F[Rounding as per IS 2:1960]
    B & D & F --> G[Ensured Surface Finish & Quality]

This ensures structural profiles meet quality and surface finish requirements as per IS 7452.

IS 7452: Testing Requirements Summary

• Rounding off results (Clause 9.1):
  Final test values must be rounded as per IS 2:1960.

  • Retain the same number of significant digits as specified in the standard.

• Test Sample Selection & Preparation (Clause 9.2):

  • Samples must be taken from the finished product.
  • Record cast number, size, and mass of each sample.
  • Samples must not be annealed or heat-treated unless the original material was treated similarly.
  • Any straightening must be done cold only.

Key Points for Testing Samples

Rounding Rule (IS 2:1960)

• If next digit < 5 → round down
• If next digit ≥ 5 → round up
• Keep significant digits consistent with standard values.

flowchart TD
    A[Finished Product] --> B[Select Test Sample]
    B --> C[Record Cast No., Size, Mass]
    C --> D{Heat Treatment?}
    D -- Yes --> E[Heat treat sample same as material]
    D -- No --> F[No heat treatment]
    E & F --> G[Cold straightening if required]
    G --> H[Perform Test]
    H --> I[Round off results per IS 2:1960]

This ensures test results are reliable and comparable as per IS 7452.

IS 7452: Marking and Packaging Key Points

Marking (Clause 11.1)

• Each length of section must be indelibly marked at intervals ≤ 1 meter.
• Marking must include the source of manufacture.

Packaging (Clause 10.1)

• Sections supplied in bundles.
• Each bundle must carry a metal tag with:
  • Source of manufacture
  • Designation of the section
  • Number of pieces in the package
  • Batch number

Additional Notes

• Rounding off test values must follow IS 2:1960.
• Mass example: Section K12B weighs 2.30 kg/m.

Summary Table for Marking & Packaging

This ensures traceability and quality control compliance per IS 7452.

flowchart LR
    A[Rolled Section] --> B[Mark every ≤ 1m with source]
    B --> C[Bundle sections]
    C --> D[Attach metal tag with info]
    D --> E{Tag Info}
    E --> F(Source of Manufacture)
    E --> G(Designation)
    E --> H(Number of pieces)
    E --> I(Batch number)

This diagram shows the marking and packaging flow per IS 7452.