Glazed Fire-Clay Sanitary Appliances, Part 4: Specific Requirements of Postmortem Slabs

IS 771 Part 4 – Scope: Dimensions and Tolerances

• Scope: Defines dimensional limits and tolerances for structural steel sections.

Key Specifications:

Rounding Off:

• Final values (test or calculation results) must be rounded per IS:2-1960.
• Retain the same number of significant digits as specified in the standard.

Summary:

• Ensures uniformity and interchangeability of steel sections.
• Critical for quality control and structural integrity.

flowchart TD
    A[Measured Dimension] --> B{Dimension >= 50 mm?}
    B -- Yes --> C[Tolerance ± 4%]
    B -- No --> D[Tolerance ± 2 mm]
    C --> E[Apply tolerance]
    D --> E
    E --> F[Round off per IS:2-1960]

This ensures compliance with dimensional accuracy for steel sections under IS 771 Part 4.

IS 771 Part 4: Key Requirements Overview

• Rounding Off Values (Clause 0.3):
  Final test or analysis results must be rounded per IS:2-1960, retaining the same number of significant figures as the specified value.

• General Requirements (Clause 2.1):
  Material, manufacturing, testing, sampling, and inspection must comply with IS 771 Part 1 (1979).

• Dimensions and Tolerances (Clause 2.4):
  Specific dimensional limits and manufacturing tolerances are defined to ensure slab quality (refer to IS 771 Part 1 for detailed tables).

• Post-Mortem Slabs (Part IV):
  Contains specialized requirements for post-mortem slab testing and evaluation to confirm compliance after production.

Typical Rounding Rule (IS:2-1960)

Summary Table: Dimensions & Tolerances (Example)

Refer IS 771 Part 1 for exact values.

flowchart TD
    A[Material & Manufacture] --> B[Testing & Sampling]
    B --> C[Dimension & Tolerance Check]
    C --> D[Final Rounding per IS:2-1960]
    D --> E[Compliance Decision]

For detailed dimension tables and test methods, consult IS 771 Part 1 alongside Part 4.

IS 771 Part 4: General Requirements Summary

• Material, Manufacture, Testing & Inspection:
  Must comply with IS 771 (Part I) - 1979.

• Dimensions and Tolerances (Clause 2.4.2):

  Dimension Range	Allowed Tolerance
  ≥ 50 mm	± 4%
  < 50 mm	± 2 mm

• Rounding Off Results (Clause 0.3):
  Test or analysis results should be rounded as per IS:2-1960, keeping the same number of significant digits as the specified value.

Practical Notes:

• Always verify dimensions within these tolerances during inspection.
• Use IS:2-1960 rounding rules to maintain consistency in reporting.

flowchart TD
    A[Start: Material & Manufacture] --> B[Conform to IS 771 Part I]
    B --> C[Measure Dimensions]
    C --> D{Dimension >= 50 mm?}
    D -- Yes --> E[Apply ±4% Tolerance]
    D -- No --> F[Apply ±2 mm Tolerance]
    E & F --> G[Perform Tests]
    G --> H[Round off results per IS:2-1960]
    H --> I[Compliance Check]

This ensures quality and uniformity per IS 771 Part 4 standards.

IS 771 Part 4: Construction - Key Points

1. General Requirements (Clause 2.1)

• Materials, manufacturing, testing, sampling, and inspection must comply with IS 771 Part 1 (1979).
• Ensures uniform quality and reliability.

2. Dimensional Tolerances (Clause 2.4.2)

3. Specifics for Post-Mortem Slabs (Part IV)

• Detailed requirements for post-mortem slabs are specified but not detailed here.
• Refer to Part IV for slab thickness, reinforcement, and curing specifics.

Summary Table: Tolerances

If you need detailed manufacturing or testing methods, refer to IS 771 Part 1.

flowchart LR
    A[Material & Manufacture] --> B[Testing & Sampling]
    B --> C[Inspection]
    C --> D[Dimensional Control]
    D --> E[Tolerances]
    E --> F[Construction Quality]

This ensures compliance with IS 771 for durable and quality construction.

IS 771 Part 4: Dimensions and Tolerances Summary

1. Dimensions (Clause 2.4.1)

• Dimensions of post-mortem slabs are as per Fig. 1 (refer to IS 771 Part 4 for exact slab sizes).

2. Tolerances (Clause 2.4.2)

• For dimensions ≥ 50 mm:
  ± 4% of the specified dimension.
• For dimensions < 50 mm:
  ± 2 mm absolute tolerance.

3. Rounding Off (Clause 0.3)

• Final values should be rounded as per IS 2-1960.
• Number of significant figures in the result must match that of the specified value.

Quick Reference Table

This ensures dimensional accuracy and uniformity in post-mortem slabs, critical for structural integrity and fitment.

flowchart LR
    A[Specified Dimension] --> B{Dimension ≥ 50 mm?}
    B -- Yes --> C[Tolerance = ±4%]
    B -- No --> D[Tolerance = ±2 mm]
    C --> E[Apply tolerance]
    D --> E

For exact slab dimensions, refer to Fig. 1 in IS 771 Part 4.

IS 771 Part 4: Dimensions & Tolerances for Post-Mortem Slabs

Key Specifications (Clause 2.4)

• Dimensions: As per Fig. 1 (refer to IS 771 Part 4 for exact slab sizes).
• Tolerances (Clause 2.4.2):
  • For dimensions ≥ 50 mm: ±4% tolerance
  • For dimensions < 50 mm: ±2 mm tolerance

Rounding Off (Clause 0.3)

• Use IS:2-1960 rounding rules.
• Retain the same number of significant digits as specified in the standard.

Summary Table: Dimension Tolerances

Notes:

• Always check Fig. 1 in IS 771 Part 4 for exact nominal slab dimensions.
• Tolerances ensure manufacturing accuracy and fitment compatibility.

flowchart TD
    A[Specified Dimension] --> B{Dimension ≥ 50 mm?}
    B -- Yes --> C[Tolerance = ±4%]
    B -- No --> D[Tolerance = ±2 mm]
    C --> E[Apply Tolerance]
    D --> E

This ensures slabs meet dimensional accuracy within permissible limits.

IS 771 Part 4 — Tolerances Summary

1. Tolerance Limits (Clause 2.4.2)

• For dimensions ≥ 50 mm:
  ± 4% of the specified dimension
• For dimensions < 50 mm:
  ± 2 mm absolute

2. Rounding Off (IS:2-1960)

• Final results (test or analysis) must be rounded off as per IS:2-1960.
• Retain the same number of significant figures as the specified value.

Example:

Key Notes:

• Apply tolerances after measurement.
• Use IS:2-1960 rounding for compliance checks.

flowchart LR
A[Specified Dimension] --> B{Dimension ≥ 50 mm?}
B -- Yes --> C[Apply ±4% tolerance]
B -- No --> D[Apply ±2 mm tolerance]
C & D --> E[Measure & Round off as per IS:2-1960]
E --> F[Check compliance]

This ensures dimensional accuracy and uniformity in steel construction elements per IS 771 Part 4.

IS 771 Part 4: Marking Specifications (Clause 3.1.1)

• Marking Requirement:
  Each post-mortem slab conforming to IS 771 Part 4 may be marked with the ISI Certification Mark.

• Purpose of ISI Mark:

  • Assures compliance with the standard under a strict system of inspection, testing, and quality control supervised by BIS.
  • Continuous conformity checks by BIS ensure product quality.

• Legal Governance:
  Use of ISI Mark is governed by the Indian Standards Institution (Certification Marks) Act and related rules.

• Additional Notes:

  • Manufacturers must obtain a license from BIS to use the ISI mark.
  • Marking ensures traceability and quality assurance.

Related Standards and References:

• IS 2:1960 - Rounding off guidelines for test results.
• Dimensions and tolerances are specified in Clause 2.4 of IS 771 Part 4.

Summary Table for Marking

flowchart LR
    A[Post-mortem Slab] --> B{Conforms to IS 771 Part 4?}
    B -- Yes --> C[Apply ISI Certification Mark]
    B -- No --> D[No Marking]
    C --> E[Product Quality Assured]
    E --> F[Continuous BIS Inspection]

For detailed marking dimensions and tolerances, refer to Clause 2.4 and IS 771 Part 4 drawings.