cast-iron steps for manholes

IS 5455 Scope - Key Points & Specifications

• Scope: Covers cast iron steps for manholes with specified dimensions and load tests.
• Dimensions: As per Pattern 1 & Pattern 2 (Fig. 1A & 1B), with ±2 mm tolerance.
• Load Test:
  • Apply 225 kg vertical load at the center of front tread (Fig. 3).
  • Load applied gradually, held for 1 minute without cracking or permanent deformation.
• Sample Testing:
  • 1 step per 50 samples may be tested if agreed (Clause 5.1).
  • Test arrangement and cost by mutual agreement.
• Rounding Off: Final test values rounded as per IS 2-1960, matching significant digits of specified values.

Load Test Application (Appendix A)

Dimension Tolerance

flowchart LR
    A[Cast Iron Step] --> B[Dimensions as per Pattern 1 or 2]
    B --> C[Tolerance ±2 mm]
    A --> D[Load Test]
    D --> E[225 kg vertical load]
    E --> F[Applied at center of front tread]
    F --> G[Hold for 1 minute]
    G --> H[No cracking or permanent deformation]

This ensures quality and safety compliance for cast iron manhole steps per IS 5455.

IS 5455: Material Requirements for Cast Iron Steps

Material Specification:

• Steps must be made of grey cast iron, minimum Grade 15 as per IS 210-1962.

Load Test Requirements:

• A proof load of 225 kg applied vertically at the center of the front tread.
• Load applied gradually without stopping.
• Step must withstand load for 1 minute without cracking or permanent deformation.

Dimensional & Manufacturing Agreement:

• Dimensions can vary if mutually agreed between purchaser and manufacturer (Clause 3.3.1).

Key Points Summary:

Rounding Off Values:

• Follow IS 2-1960 rules for rounding test results to the same decimal places as specified.

flowchart TD
    A[Manufacture Step] --> B[Material: Grey Cast Iron Grade 15]
    B --> C[Apply 225 kg Load at Center of Front Tread]
    C --> D[Hold Load for 1 Minute]
    D --> E{No Cracks or Permanent Set?}
    E -- Yes --> F[Step Passes Test]
    E -- No --> G[Step Fails Test]

This ensures compliance with IS 5455 material and testing requirements.

IS 5455: Dimensions and Design of Cast Iron Steps for Manholes

Key Specifications:

• Dimensions: As per Fig. 1A (Pattern 1) and Fig. 1B (Pattern 2) in the standard.
• Tolerance: ±2 mm on all dimensions.
• Units: All dimensions in millimeters (mm).
• Alternate Dimensions: Permitted if mutually agreed between manufacturer and purchaser (Clause 3.3.1).

Load Test:

• Proof Load: 225 kg applied vertically at the center of the front tread (Fig. 3).
• Duration: Load held for 1 minute without cracking or permanent deformation.
• Support: Step is supported as indicated in Fig. 2 for proof load test.

Summary Table (Typical Dimensions from Patterns):

(Exact dimensions to be referred from IS 5455 Fig. 1A & 1B)

Design Notes:

• Steps must withstand the specified proof load without damage.
• Manufacturing deviations beyond ±2 mm require purchaser approval.
• Load application and support during testing must follow the standard's schematic.

flowchart LR
    A[Cast Iron Step] --> B[Support as per Fig. 2]
    B --> C[Apply 225 kg Load at Front Tread Center]
    C --> D[Hold Load for 1 Minute]
    D --> E{No Cracking or Permanent Deformation?}
    E -- Yes --> F[Pass Test]
    E -- No --> G[Fail Test]

References: IS 5455 Clause 3.3, 3.3.1, 1.2; Figures 1A, 1B, 2, 3.

IS 5455 - Surface Coating for Cast Iron Steps: Key Specifications

• Coating Material (Clause 4.1):

  • Tar-based material, black bituminous composition, or cashew-nut shell liquid.
  • Coating must be smooth, tenacious, non-flowing at 63°C, and not brittle at 0°C.

• Performance Requirements:

  • Coating should withstand temperature without flowing or chipping.

• Test Load (Clause 1.2, Table A-1.2):

  • Apply 225 kg vertically at the center of the front tread (see Fig. 3).
  • Load applied gradually without stop, sustained for 1 minute.
  • No cracking, permanent setting, or injury allowed.

• Rounding Off (Clause 0.4):

  • Final test values rounded as per IS 2-1960, maintaining significant figures of specified values.

Summary Table: Surface Coating Requirements

flowchart TD
    A[Cast Iron Step] --> B[Surface Coating]
    B --> C{Material Type}
    C -->|Tar Base| D[Apply Coating]
    C -->|Bituminous| D
    C -->|Cashew-nut Shell Liquid| D
    D --> E[Temperature Test]
    E -->|63°C| F[No Flow]
    E -->|0°C| G[No Brittle Chip]
    D --> H[Load Test]
    H --> I[225 kg Load for 1 min]
    I --> J[No Cracks or Permanent Setting]

This ensures durable, weather-resistant surface protection for cast iron manhole steps per IS 5455.

IS 5455: Testing and Inspection Key Points

Load Test (Clause 5.1 & Appendix A)

• Test Load: 225 kg applied vertically at the center of the front tread (see Fig. 3).
• Load Application: Gradual and continuous without stopping.
• Duration: Load maintained for 1 minute.
• Acceptance: No cracking, injury, or permanent deformation allowed.
• Sample Frequency: 1 step per 50 samples (if agreed between purchaser and manufacturer).

Test Setup (Fig. 2 & 3)

• Support: Step clamped as per Fig. 2.
• Load Point: Center of the front tread (Fig. 3).

Marking & Certification (Clause 6.1.1)

• Cast iron steps may carry ISI Certification Mark ensuring compliance with ISI supervised inspection and quality control.

Rounding Off (Clause 3.3.1)

• Test results rounded per IS 2-1960 to the same significant digits as specified values.

Summary Table: Load Test Parameters

flowchart LR
    A[Cast Iron Step] --> B[Clamp as per Fig. 2]
    B --> C[Apply Load 225 kg at center (Fig. 3)]
    C --> D{Hold Load for 1 minute}
    D -->|No cracks or permanent set| E[Pass]
    D -->|Cracks or deformation| F[Fail]

For detailed procedures and agreements, refer to Clause 5.1 and Appendix A of IS 5455.

IS 5455: Marking and Certification for Cast Iron Steps

Marking Requirements (Clause 6.1 & 6.1.1):

• Each cast iron step shall be marked with:

  • Manufacturer's name or trade-mark.
  • The ISI Certification Mark (optional but recommended).

• The ISI Mark assures compliance with IS 5455 under strict inspection, testing, and quality control by ISI.

Load Test (Appendix A, Clause 5.1 & 1.2)

Notes on Certification Mark Use:

• Governed by Indian Standards Institution (Certification Marks) Act.
• License conditions for ISI Mark use available from ISI offices.
• Continuous product conformity checks by ISI.

Summary Diagram: Load Test Setup

flowchart LR
    A[Cast Iron Step] --> B[Support Clamping (Fig. 2)]
    B --> C[Load Application at Center of Front Tread (225 kg)]
    C --> D[Load held for 1 min]
    D --> E{No Cracking or Permanent Set?}
    E -- Yes --> F[Pass Test]
    E -- No --> G[Fail Test]

For license & detailed conditions, contact nearest ISI regional office (e.g., Manak Bhavan, New Delhi).

IS 5455 Load Test Procedure Summary

Key Specifications (Appendix A, Clause 1.2):

• Load: 225 kg applied vertically.
• Load Application Point: Centre of the front tread (Fig. 3).
• Duration: Load applied gradually without stopping and maintained for 1 minute.
• Acceptance Criteria: No cracking, injury, or permanent set.

Test Setup (Clause A-1.1):

• Step specimen clamped horizontally.
• Only tread portion projects as a cantilever (Fig. 2).
• Accurate positioning of the center nib is critical.

Procedure Steps:

1. Clamp the step horizontally, leaving the tread cantilevered.
2. Apply 225 kg load gradually at the tread center.
3. Maintain load for 1 minute.
4. Inspect for damage or permanent deformation.

Visual Summary:

flowchart LR
    A[Clamp Step Horizontally] --> B[Load Applied at Centre of Tread]
    B --> C[Load = 225 kg]
    C --> D[Maintain Load for 1 Minute]
    D --> E{No Cracks or Permanent Set?}
    E -->|Yes| F[Pass Test]
    E -->|No| G[Fail Test]

Note: Only 1 in 50 samples may be tested if agreed by manufacturer and purchaser (Clause 5.1). ISI mark usage governed by ISI certification rules (Clause 6.1.1).