Rolling and cutting tolerances for hot rolled steel products

IS 1852 - Scope & Key Specifications for Hot Rolled Steel Sections

Scope

• Covers types of hot rolled steel products (beams, columns, channels, angles).
• Rolling and cutting tolerances referenced in Appendix A.
• Applicable to ordinary quality structural steel.

Key Tolerances & Limits

Notes

• Camber and Sweep: Deviation along length measured as per Fig.3 (max 0.2% of length).
• Off-centre Web: Web position relative to flange width (see Fig.2).

flowchart LR
    A[Hot Rolled Steel Sections] --> B[Flange Width Tolerance]
    A --> C[Off-centre of Web Limits]
    A --> D[Camber & Sweep Limits]
    B --> |≤100 mm| B1[± 2.0 mm]
    B --> |100-125 mm| B2[± 2.5 mm]
    B --> |125-250 mm| B3[± 4.0 mm]
    C --> |≤300 mm| C1[3.0 mm]
    C --> |300-450 mm| C2[4.0 mm]
    C --> |450-600 mm| C3[5.0 mm]
    D --> |Length| D1[0.2% max]

This summary ensures compliance with IS 1852 tolerances for beams and columns.

IS 1852: Key Definitions & Specifications (Clause 4.1 - Beams and Columns)

1. Off-centre of Web (Clause 4.1.4)
   The web's off-centre must be within limits based on section depth (see Fig. 2):

• B = Actual flange width

2. Width of Flange Tolerance (Clause 4.1.2)

3. Flanges Out-of-Square or Out-of-Parallel (Clause 4.1.3)

Note: Refer Appendix A (Clause 1.1.1) for material & dimension standards of hot-rolled sections.

flowchart LR
    A[Section Depth] -->|≤ 300 mm| B[Max Off-centre = 3 mm]
    A -->|300-450 mm| C[Max Off-centre = 4 mm]
    A -->|450-600 mm| D[Max Off-centre = 5 mm]

These ensure dimensional accuracy and proper alignment in hot-rolled steel beams and columns per IS 1852.

Nominal Weight Calculation as per IS 1852

• Density of steel: 7.85 g/cm³ (Clause 3.1)
• Formula for nominal weight (W):

[ W = \text{Volume} \times \text{Density} ]

For a steel sheet or section:

[ W = L \times B \times T \times 7.85 , \text{(kg/m}^3) ]

Where:

• (L) = length (m)
• (B) = breadth/width (m)
• (T) = thickness (m)

Weight Tolerances on Sheets (Clause 9.4.1)

Rolling Tolerance for Structural Steel Sections (Clause 8.3)

• Weight per meter tolerance: ±10% of specified weight (from IS 1730 Part 3)

Summary

• Use density = 7.85 g/cm³ for nominal weight calculation.
• Apply dimensional tolerances as per IS 1730.
• Weight tolerances vary with thickness, tighter for thicker sheets.
• Structural sections have ±10% weight tolerance per meter.

flowchart LR
    A[Input Dimensions: L, B, T] --> B[Calculate Volume: L×B×T]
    B --> C[Multiply by Density: 7.85 g/cm³]
    C --> D[Nominal Weight (kg)]
    D --> E{Check Thickness}
    E -->|≤1.25 mm| F[Tolerance ±9%]
    E -->|1.25-1.60 mm| G[Tolerance ±8%]
    E -->|1.60-4.00 mm| H[Tolerance ±7%]

This ensures accurate weight estimation and compliance with IS 1852 standards.

IS 1852: Rolling Tolerances for Structural Steel Sections

Key Specifications:

• Weight Tolerance (Clause 4.5.5):
  ±2.5% of specified weight per meter (±4% for Fe 310-0 steel as per IS 1977-1975).

• Weight Calculation (Clause 3.1):
  Use steel density = 7.85 g/cm³ for nominal weight calculations.

• Consignment Weight Tolerance (Clause 8.3.1.1):
  For consignments > 5 tonnes, tolerance on theoretical weight = ±5%.

General Rolling Tolerances:

• Applies to beams, channels, angles, tees, bars, flats, plates, strips, and sheets.
• Tolerances cover dimensional deviations and weight variations during hot rolling.

Formula for Theoretical Weight (W) per meter:

[ W = \text{Cross-sectional Area} \times 7.85 \times 10^{-3} \quad (\text{in kg/m}) ]

Where cross-sectional area is in mm².

Summary Table: Typical Weight Tolerance Limits

flowchart LR
    A[Hot Rolled Steel Section] --> B[Calculate Theoretical Weight]
    B --> C{Check Steel Type}
    C -->|Ordinary| D[Apply ±2.5% Tolerance]
    C -->|Fe 310-0| E[Apply ±4% Tolerance]
    B --> F{Consignment Weight > 5t?}
    F -->|Yes| G[Apply ±5% Tolerance]
    F -->|No| H[Use Section Tolerance]

Note: For detailed dimensional tolerances, refer to IS 1852 tables and IS 808 for structural steel sections.

IS 1852 - Beams and Columns: Key Specifications

1. Depth of Beams (Clause 4.1.1)

2. Width of Flange (Clause 4.1.2)

3. Off-Centre of Web (Clause 4.1.4)

Notes:

• B = Actual flange width (used for web off-centre limits).
• These tolerances ensure proper fit and structural integrity.
• Always verify actual dimensions against these limits during fabrication and erection.

flowchart TD
    A[Beam/Column Section] --> B[Measure Depth]
    B --> C{Depth Range}
    C -->|≤200 mm| D[Depth Tolerance +3/-2 mm]
    C -->|200-400 mm| E[Depth Tolerance ±3 mm]
    C -->|400-600 mm| F[Depth Tolerance ±4 mm]

    A --> G[Measure Flange Width]
    G --> H{Width Range}
    H -->|≤100 mm| I[Flange Tolerance ±2 mm]
    H -->|100-125 mm| J[Flange Tolerance ±2.5 mm]
    H -->|125-250 mm| K[Flange Tolerance ±4 mm]

    A --> L[Measure Web Position]
    L --> M{Depth Range}
    M -->|≤300 mm| N[

IS 1852: Key Specifications for Angles (Clause 4.3)

1. Leg Length Tolerances (Clause 4.3.1)

• For unequal leg angles (e.g., 45 x 30 mm), the longer leg tolerance is +2.0 / -1.5 mm.
• The shorter leg tolerance follows the above table.

2. Out-of-Square Tolerance (Clause 4.3.2)

• Legs must be perpendicular within ±1.0°.

Summary Table for Leg Length Tolerance

Practical Notes:

• Ensure angle legs meet these tolerances for fit and structural integrity.
• Out-of-square tolerance controls angular deviation critical for connections.

graph TD
A[Angle Section] --> B[Leg Length]
A --> C[Leg Perpendicularity]
B --> D{Length Range}
D -->|≤ 45 mm| E[±1.5 mm]
D -->|45-100 mm| F[±2.0 mm]
D -->|>100 mm| G[±2%]
C --> H[±1.0°]

This ensures dimensional accuracy and angular precision for structural steel angles.

IS 1852: Out-of-Square and Out-of-Parallel Tolerances

1. Flanges Out-of-Square / Out-of-Parallel (Clauses 4.1.3 & 4.2.3)

• Tolerance for flange parallelism:
  Flanges must be parallel within 1 in 60 (approx. 1.67°) tolerance (Clause 4.2.3).

• Tolerance for flange out-of-square (A + A') depends on flange width (B):

(Clause 4.1.3, Table 4.1)

2. Angles (Clause 4.3.2)

• Legs must be perpendicular within ±1.0° tolerance.

3. Parallelogram Sections (Clause 6.3)

• Out-of-square tolerance for overall width to be agreed between purchaser and supplier.

Summary Diagram (Flange Out-of-Square)

graph LR
A[Flange Edge] -- A --> B[Flange Edge]
A' -- Opposite Edge --> B
note right of A: A + A' ≤ Tolerance (3mm or 3%)

Key Points:

• Flange parallelism: 1 in 60 max deviation
• Out-of-square tolerance depends on flange width (3mm or 3%)
• Angles legs perpendicular within ±1°
• Parallelogram section tolerance is negotiable

This ensures dimensional accuracy and fitment in structural steel sections.

IS 1852 - Bulb Angles Key Specifications (Clause 4.5)

1. Depth (Longer Leg Length) Tolerances (Clause 4.5.1)

2. Out-of-Square Tolerance (Clause 4.5.3)

• Legs of bulb angles (and unequal leg angles) must be perpendicular within ±1.0°.

Notes:

• Bulb angles have one leg longer than the other with a bulb (thickened) edge for strength.
• The tolerances ensure proper fit and structural performance.
• Refer Clause 4.3 for equal and unequal leg angle specifications.

flowchart TD
    A[Bulb Angle] --> B[Longer Leg Length]
    B --> C{Depth Range}
    C -->|≤125 mm| D[Tolerance: +2.5 / -1.5 mm]
    C -->|125-200 mm| E[Tolerance: +3.0 / -2.0 mm]
    C -->|200-400 mm| F[Tolerance: +3.5 / -2.5 mm]
    A --> G[Legs Perpendicularity]
    G --> H[Tolerance: ±1.0°]

This summary helps ensure bulb angles conform to IS 1852 dimensional and angular standards.

IS 1852: Bars in Straight Length and Coils - Key Specifications

1. Size Tolerances

Measurement excludes heavy ends.

2. Weight Tolerances for Straight Bars (IS 1732-1971)

No weight tolerance for coiled bars.

3. Out of Shape Tolerance (Coiled Bars)

• Max difference between max & min diameter (round) or adjoining sides (square) ≤ 0.65 mm

Summary Diagram: Tolerances Overview

graph TD
    A[Bars] --> B[Straight Length]
    A --> C[Coils]
    B --> B1[Size Tolerance ±0.5 to ±1.3 mm]
    B --> B2[Weight Tolerance ±3% to ±7%]
    C --> C1[Size Tolerance ±0.5 mm (≤12 mm)]
    C --> C2[Out of Shape ≤0.65 mm]
    C --> C3[No Weight Tolerance]

Note: Refer to IS 1732 for weight calculation formulas and tables.

IS 1852: Tolerances for Flats and Sheets

1. Weight Tolerances (Clause 6.4)

• Flats ≤ 3 mm thickness: ±5% of specified weight.
• Flats > 3 mm thickness: ±3% of specified weight (per IS 1731-1971 Table 1).

2. Width Tolerances for Flats (Clause 6.1)

3. Thickness Tolerances for Flats (Clause 6.2 & 9.3.2)

*For sheets from hand mills, thickness toler

IS 1852 Thickness Tolerances Summary

1. Thickness Tolerances for Sheets (Clause 9.3.2)

2. Thickness Tolerances in Percentage (Clause 7.3)

3. Thickness Tolerances for Strip Widths up to 500 mm (Clause 8.2.1)

IS 1852: Tolerances for Strips

1. Width Tolerances for Trimmed Edges (Clause 8.1.1)

2. Width Tolerances for As-Rolled Edges (Clause 8.1.2)

3. Thickness Tolerances

Up to 500 mm width (Clause 8.2.1):

**Above 500 mm width (Clause

Weight Tolerances for Bundles and Consignments (IS 1852)

Key Points from IS 1852:

• For individual bundles and consignments ≤ 5 tonnes:

  • Tolerance = ±7% of theoretical weight (Clause 9.4.2)

• For individual consignments > 5 tonnes:

  • Tolerance = +5% (Clause 9.4.2.1)
  • Cutting tolerance also ±5% (Clause 8.3.1.1)

Weight Tolerance on Individual Sheets (Clause 9.4.1):

Theoretical Weight Calculation Reference:

• Use Table 2 of IS 1730 (Part 2)-1974 for theoretical weights of sheets.

Summary:

• Bundles ≤ 5t: ±7%
• Consignments > 5t: +5%
• Sheets: Tolerance varies by thickness (±7 to ±9%)
• Theoretical weights per IS 1730 Part 2.

This ensures quality control and consistency in steel sheet deliveries.

flowchart TD
    A[Calculate Theoretical Weight (IS 1730 Part 2)] --> B{Bundle/Consignment Weight}
    B -->|≤ 5 tonnes| C[Tolerance ±7%]
    B -->|> 5 tonnes| D[Tolerance +5%]
    A --> E{Sheet Thickness}
    E -->|≤ 1.25 mm| F[Tolerance ±9%]
    E -->|1.25 < t ≤ 1.60 mm| G[Tolerance ±8%]
    E -->|1.60 < t ≤ 4.00 mm| H[Tolerance ±7%]

IS 1852: Measurement and Rounding Off Rules

1. Rounding Off (Clause 0.4)

• Final test or calculation values must be rounded off as per IS:2-1960.
• The number of significant digits retained in the rounded value should match that of the specified value in IS 1852.

2. Tolerances on Bars in Straight Length

Size Tolerance (Clause 5.1.1)

Weight Tolerance (Clause 5.1.3)

Weight per meter is based on IS 1732-1971 tables.

3. Tolerances on Width of Strips (Clause 8.1.1)