Recommendations for welding cold worked bars for reinforced concrete construction

IS 9417: Scope Summary

• Scope: Covers welding of mild steel plain and deformed bars for reinforced concrete construction.
• Referenced Standards: Essential adjuncts listed in Annex A include:
  • IS 1786: Specification for high strength deformed steel bars and wires.
  • IS 812: Glossary of welding and cutting terms.
  • IS 814 (Part 1): Specification for covered electrodes for metal arc welding.
  • IS 2751: Code of practice for welding of mild steel bars.
  • IS 818: Safety and health requirements in welding.
  • Others related to welding equipment, safety, and accessories.

Key Points:

• Welding must comply with IS 2751 for welding practice.
• Definitions per IS 812 apply.
• Welding equipment must maintain uniform axial pressure (hydraulic or mechanical pressurizer).
• Standard Mark usage is governed by BIS ensuring quality and conformity.

Important Table: Referenced IS Codes (Annex A excerpt)

Welding Equipment Specification (Clause 2.1.3):

• Pressurizer: Hydraulic or mechanical, manual or electric.
• Function: Maintain uniform axial pressure during welding.

For detailed welding procedures, safety, and equipment specifications, refer to the respective IS codes listed in Annex A.

flowchart LR
    A[IS 9417 Scope] --> B[Welding of mild steel bars]
    A --> C[Referenced IS Codes]
    C --> D[IS 1786 - Steel bars]
    C --> E[IS 2751 - Welding practice]
    C --> F[IS 814 - Electrodes]
    C --> G[IS 818 - Safety]
    A --> H[Equipment Requirements]
    H --> I[Pressurizer: Hydraulic/Mechanical]
    H --> J[Uniform axial pressure]

Summary: IS 9417 governs welding

IS 9417 - References Summary

Key Indian Standards Referenced (Annex A, Clause 2.1):

Important Notes:

• Definitions in IS 812:1957 apply to IS 9417.
• These standards cover welding symbols, electrodes, safety, equipment, and steel reinforcement specs.
• Use the latest edition/amendments for compliance.
• BIS governs the use of the Standard Mark ensuring quality and conformity.

Quick Reference Diagram: Relationship of IS 9417 with Other Codes

graph LR
  A[IS 9417] --> B[IS 812: Glossary]
  A --> C[IS 1786: Steel Bars]
  A --> D[IS 814: Electrodes]
  A --> E[IS 2751: Welding Practice]
  A --> F[IS 818: Safety]
  A --> G[IS 9595: Arc Welding

IS 9417 Definitions Summary

• Reference Standard: Clause 3.1 states that definitions in IS 812:1957 (Glossary of terms relating to welding and cutting of metals) apply to IS 9417.

• Key Points from IS 812:1957 (relevant to welding & cutting):

  • Welding terms: Fusion, weld bead, weld joint, slag, electrode, etc.
  • Cutting terms: Flame cutting, plasma cutting, kerf, etc.

• Additional References: IS 9417 refers to multiple standards for welding practice, electrodes, safety, and equipment (see Annex A), e.g., IS 2751 for welding of steel bars in RCC.

Important Notes:

• IS 9417 does not define terms itself but defers to IS 812:1957.
• For detailed definitions, consult IS 812:1957 directly.
• Related standards cover:
  • Welding symbols (IS 813)
  • Electrodes specs (IS 814)
  • Welding safety (IS 818)
  • Welding of steel bars (IS 2751)

Quick Reference Table: Key Related IS Codes

This ensures consistent terminology across welding and reinforcement practices per IS 9417.

flowchart LR
    A[IS 9417 Definitions] --> B[Refer IS 812:1957 Glossary]
    B --> C[Welding Terms]
    B --> D[Cutting Terms]
    A --> E[Related Standards]
    E --> F[IS 813 Symbols]
    E --> G[IS 814 Electrodes]
    E --> H[IS 2751 Welding RCC Bars]
    E --> I[IS 818 Safety]

Summary: Use IS 812:1957 for all definitions in IS 9417; consult related IS codes for detailed welding and reinforcement specifications.

IS 9417: Plans and Drawing for Welding Reinforced Steel Bars

• Clause 4.1: Plans and drawings must follow SP 46:1988 — Engineering Drawing Practice for Schools and Colleges. This ensures clarity and standardization in detailing welded reinforcements.

• Symbols: Use welding symbols as per IS 813:1986 for consistency in indicating weld types and locations on drawings (Clause 5.1).

• References: For detailed welding practice, equipment, and safety, refer to related IS codes:

  • IS 2751:1979 – Welding of mild steel plain and deformed bars for RCC.
  • IS 814 (Part 1):1974, IS 815:1974 – Electrode specifications.
  • IS 812:1957 – Glossary of welding terms.
  • IS 818:1968 – Safety in welding.

Summary Table: Key Drawing Standards for Welding Reinforcement

Typical Welding Symbol Example (per IS 813:1986):

graph LR
A[Base Metal] -->|Weld Symbol| B[Weld Metal]
B --> C[Reinforcement]

• Arrow points to weld location.
• Symbol indicates weld type (e.g., fillet, butt).
• Supplementary symbols specify weld size, length, and finish.

Note: For detailed weld sizes, lengths, and joint types, consult SP 46:1988 and IS 2751:1979 directly.

IS 9417: Materials Key Specifications & References

• Parent Metal: Must be weldable steel conforming to IS 1786:1985 (High strength deformed steel bars for concrete reinforcement).

• Welding Electrodes: Covered electrodes as per IS 814 (Part 1):1974 for metal arc welding of structural steels.

• Welding Practice: Follow IS 2751:1979 for welding mild steel plain and deformed bars in reinforced concrete.

• Safety: Use eye and face protection per IS 3016:1982; adhere to safety codes in IS 818:1968 and IS 1179:1967.

• Welding Equipment: Specifications for arc welding transformers (IS 1851:1975), DC welding generators (IS 2635:1975), and welding cables (IS 9857:1981).

Summary Table of Key Material References

Welding Quality Assurance

• Use weldable parent metal per IS 1786.
• Follow recommended electrode classifications (IS 815:1974).
• Ensure equipment compatibility with welding standards.
• Maintain safety protocols during welding operations.

flowchart TD
    A[Parent Metal: IS 1786] --> B[Welding Electrodes: IS 814]
    B --> C[Welding Practice: IS 2751]
    C --> D[Equipment: IS 1851 & IS 2635]
    D --> E[Safety: IS 818, IS 1179, IS 3016]

This ensures welded joints

IS 9417: Selection of Equipment and Accessories for Welding Cold-Worked Bars

Key Points from Clause 6.1 and Annex B:

• Equipment must conform to relevant Indian Standards (e.g., IS 813 for welding symbols).
• Machines should be:
  • Designed for the climatic conditions of use.
  • Well-made, adhering to relevant IS codes.
  • Have adequate current capacity for the electrode sizes used.
• Where IS standards are unavailable, use best quality equipment with capacity suitable for the welding procedure.

Typical Specifications for Welding Equipment:

Summary Diagram: Equipment Selection Criteria

graph TD
    A[Select Welding Equipment] --> B[Conform to IS Standards]
    A --> C[Capacity Adequate for Electrode Size]
    A --> D[Suitable for Climatic Conditions]
    A --> E[High-Quality Accessories]

References:

• IS 9417 Clause 6.1 & Annex B
• IS 813:1986 (Welding Symbols)

Ensure equipment rating matches electrode/bar size and environmental conditions for reliable welds.

IS 9417: Safety and Health Requirements Summary

• Safety Standards:
  Welding safety follows IS 818:1968 (Code of practice for safety and health in welding & cutting) and fire precautions per IS 3016:1982.

• Parent Metal:
  Must conform to IS 1786:1985 (High strength deformed steel bars).

• Protective Equipment:
  Use non-conducting hand screens or helmets with protective filter lenses per IS 1179:1967 to shield eyes/face from UV and IR rays during welding.

• Key IS References for Welding Safety:

  IS No.	Title
  IS 818:1968	Safety & health in welding/cutting
  IS 3016:1982	Fire precautions in welding/cutting
  IS 1179:1967	Eye & face protection equipment
  IS 1786:1985	Steel bars for reinforcement

Protective Filter Lens Function:

• Cuts off harmful UV & IR rays
• Ensures clear vision of the welding arc

Summary Diagram:

flowchart TD
  A[Welding Operation] --> B[Safety Measures]
  B --> C[IS 818:1968 Safety Code]
  B --> D[Fire Precautions (IS 3016:1982)]
  B --> E[Protective Equipment]
  E --> F[Helmet with Filter Lens (IS 1179:1967)]
  A --> G[Parent Metal Quality]
  G --> H[IS 1786:1985 Steel Bars]

For detailed safety practices, always refer to IS 818 and IS 3016 for welding operations and fire precautions respectively.

IS 9417: Preparation for Welding – Key Points

• Clause 10.3.2, 10.5.2, 1.1, 10.4.2 emphasize cleanliness and joint preparation:

  • Joint faces and adjacent areas must be free from scale, dirt, grease, paint, rust, and contaminants.
  • Edge preparation is not required for lap welds.

• Annex C provides detailed recommendations on welding procedure and equipment preparation, including:

  • Proper edge beveling for butt joints (e.g., single V, double V, U, or J types).
  • Preheating and interpass temperature controls.
  • Selection and maintenance of welding equipment.

Typical Edge Preparation (Butt Joints)

Cleaning Procedure Summary

• Remove mill scale by grinding or wire brushing.
• Degrease with solvents.
• Dry the surface before welding.

flowchart TD
    A[Start: Welding Preparation] --> B{Joint Type}
    B -->|Lap Joint| C[No Edge Preparation]
    B -->|Butt Joint| D[Edge Preparation]
    D --> E[Clean Joint Faces]
    E --> F[Check Groove Angle & Root Gap]
    F --> G[Preheat if Required]
    G --> H[Proceed to Welding]

Summary: Cleanliness and proper edge preparation (except lap joints) are crucial for weld quality per IS 9417. Refer Annex C for detailed welding procedure guidelines.

IS 9417 Key Specifications for Electrodes

1. Electrode Size (Clause 10.5.3)

2. Electrode Standard (Clause 9.1)

• Electrodes must conform to IS 814 (Part 1): 1974.

3. Storage Recommendations (Clause 3.1.7)

• Use heated storage cabinets or drying ovens for low hydrogen electrodes.
• Store other electrodes in dry conditions, especially in moist ambient environments (e.g., site work).

Summary Diagram: Electrode Size Selection

graph TD
    A[Bar Diameter d] -->|≤10 mm| B[Electrode Max 2.5 mm]
    A -->|>10 to ≤18 mm| C[Electrode Max 3.15 mm]
    A -->|>18 to ≤28 mm| D[Electrode Max 4.0 mm]
    A -->|>28 mm| E[Electrode Max 5.0 mm]

Note: Proper electrode size ensures weld quality and compatibility with bar diameter. Storage conditions critically affect weld integrity.

IS 9417: Welding Processes and Procedures - Key Points

1. Electrodes (Clause 9.1)

• Electrodes must conform to IS 814 (Part 1): 1974.
• Ensures compatibility and quality for welding.

2. Preparation for Welding (Clause 10.3.2)

• Surfaces must be clean, free from rust, oil, and moisture.
• Edges should be beveled as per thickness to ensure full penetration.
• Proper alignment and fit-up are essential.

3. Butt Welding by Shielded Metal Arc Welding (SMAW) (Clause 10.3)

• Use suitable electrodes per IS 814.
• Maintain correct welding parameters:
  • Current: As per electrode size.
  • Voltage: Stable arc voltage.
• Multiple passes may be needed for thick sections.
• Preheat and inter-pass temperature control may be required.

4. Butt Welding by Gas Pressure Welding (Clause 10.4)

• Edges are heated by gas flame until plastic state.
• Pressure is applied to forge the joint.
• Used for pipes and tubes, ensuring leak-proof joints.

Typical Welding Parameters (Example for SMAW):

flowchart LR
    A[Preparation] --> B[Cleaning & Beveling]
    B --> C[Welding Process Selection]
    C --> D{Process Type}
    D -->|SMAW| E[Shielded Metal Arc Welding]
    D -->|Gas Pressure| F[Gas Pressure Welding]
    E --> G[Electrode per IS 814]
    F --> H[Heating & Pressure Application]

Summary: Follow IS 814 electrodes, proper surface prep, and select welding process per application. Control parameters for sound joints.

IS 9417: Weld Quality and Inspection - Key Points

1. Weld Preparation & Procedure (Clauses 10.3.2 & 10.5.4)

• Arc striking point: Strike arc ~0.2d from joint center, within the groove to be welded over.
• Welding direction:
  • Horizontal lap joints: weld as per Fig. 3 (electrode movement shown).
  • Vertical lap joints: weld from bottom to top (rising).
• Lap joint dimensions:
  • Single side weld: length = 5d (d = nominal bar diameter).
  • Double side weld: length = 2.5d each side.
• Strapped joints: Strap cross-sectional area ≥ bar cross-section.

2. Visual Inspection (Clause 11)

• Inspect welds for:
  • Uniformity and continuity.
  • Absence of cracks, porosity, or slag inclusions.
  • Proper weld size and penetration.

3. Test Welds & Quality Control (Clauses 12.1 & 13)

• Initial test welds: 3 tensile + 3 bend test pieces under local conditions.
• Repeat tests if changes occur in:
  • Welding process, bar grade, electrode, welder, or welding position.
• Welding equipment must conform to relevant IS standards or be of best available quality (Clause 6.1).

4. Summary Table: Lap Joint Weld Length

flowchart LR
    A[Start Welding] --> B{Position?}
    B -->|Horizontal| C[Strike arc ~0.2d in groove, weld horizontally]
    B -->|Vertical| D[Strike arc ~0.2d in groove, weld bottom to top]
    C --> E[Weld lap joint length: 5d single side or 2.5d double side]
    D --> E
    E --> F[Visual Inspection]
    F --> G{Pass?}
    G -->|Yes| H[Proceed to Production]
    G -->|No| I[Rework or Reject

Initial Tests (IS 9417: Clause 12)

Purpose:
To verify weld quality under actual production conditions before starting production welding.

Key Specifications:

• Test welds: 3 tensile test pieces + 3 bend test pieces.
• When to repeat tests:
  • Change in welding process
  • Change in steel bar grade
  • Change in electrode type/size
  • Change in welder
  • Change in welding position (except easier positions)

Bend Test (Clause 13.1.2)

• Welded joint must bend 60° around mandrel without cracking.
• Remove welding flash/reinforcement at mandrel contact point before testing.

Misalignment Limit (Clause 11.5)

• Max misalignment ≤ min(¼ × bar diameter, 5 mm)
• For unequal diameters, use smaller diameter for calculation.

References for Initial Tests (Annex A)

• IS 2751: Welding mild steel plain & deformed bars.
• IS 1786: High strength deformed steel bars.
• IS 814 (Part 1): Covered electrodes for welding structural steels.

flowchart LR
    A[Start: Prepare test welds] --> B{Is welding process/new conditions changed?}
    B -- Yes --> C[Repeat initial tests: 3 tensile + 3 bend]
    B -- No --> D[Proceed to production welding]
    C --> D

Summary: Initial tests ensure weld integrity with minimal samples before production. Bend and tensile tests confirm weld ductility and strength, with strict limits on misalignment and test conditions.

IS 9417 - Quality Control Tests Summary

1. Initial Test Welds (Clause 12.1)

• Conducted before production welding under local conditions.
• Tests: Tensile test (3 specimens) + Bend test (3 specimens).
• Repeat if changes occur in:
  • Welding process
  • Steel grade
  • Electrode type/size
  • Welder
  • Welding position (except easier positions)

2. Quality Control Tests (Clause 13)

• Follow tests as per Clause 13 (detailed tests on weld quality).
• Retests as per Table 14 (Clause 2.1) if initial tests fail.

3. Misalignment Limits (Clause 11.5)

• Max misalignment = min(1/4 bar diameter, 5 mm)
• For unequal bars, use smaller diameter for evaluation.

4. Referenced IS Standards (Annex A)

• IS 1786: High strength deformed bars
• IS 2751: Welding of mild steel plain and deformed bars
• IS 814 (Part 1): Covered electrodes specification
• IS 815: Classification of electrodes
• IS 818: Safety in welding
• Others for welding accessories, safety, and equipment.

Key Formula for Misalignment:

[ \text{Max Misalignment} = \min \left(\frac{d}{4}, 5 \text{ mm}\right) ] where (d) = bar diameter.

Diagram: Welding Quality Control Flow

flowchart TD
    A[Start: Pre-production Welding] --> B{Initial Test Welds}
    B -->|Pass| C[Production Welding]
    B -->|Fail| D[Retest with Adjustments]
    D --> B
    C --> E{Changes in Process?}
    E -->|Yes| B
    E -->|No| F[Continue Production]

Note: Refer to IS 9417 Clause 13 and related IS codes for detailed test procedures and acceptance criteria.

IS 9417: Acceptance Criteria Key Points

1. Misalignment (Clause 11.5)

• Maximum allowed misalignment of welded bars:
  • ≤ ¼ of bar diameter OR
  • ≤ 5 mm, whichever is less.
• For unequal diameters, use the smaller diameter for evaluation.

2. Retests (Clause 2.1)

• Retests are governed by Table 14 (not fully provided here).
• Typically involves mechanical and visual inspections per weld batch.

3. Referenced Standards (Annex A)

• Welding practice and materials must comply with relevant IS codes, e.g.:
  • IS 1786: High strength deformed steel bars.
  • IS 2751: Welding of mild steel plain and deformed bars.
  • IS 814 (Part 1): Covered electrodes for metal arc welding.
  • IS 812: Glossary of welding terms.

4. General Acceptance Criteria Summary

Diagram: Misalignment Check

graph LR
A[Bar 1] -- Weld --> B[Bar 2]
B -- Measure misalignment --> C{Misalignment ≤ min(¼ d, 5mm)?}
C -- Yes --> D[Accept weld]
C -- No --> E[Reject weld]

Summary: Ensure weld misalignment is minimal, weld integrity is visually and mechanically sound, and all welding accessories comply with IS standards listed in Annex A.

IS 9417: Gas Pressure Welding (Clause 10.4 & Annex C)

Key Specifications:

• Process: Hot forging by heating bar ends with oxy-acetylene multi-nozzle burner.
• Equipment:
  • Oxygen & acetylene cylinders with regulators
  • Multi-nozzle burner
  • Clamping unit
  • Pressurizer to apply axial pressure

Welding Steps:

1. Clean bar ends.
2. Clamp bars axially.
3. Heat ends uniformly until plastic state (bright orange).
4. Apply axial pressure to forge ends together.
5. Allow to cool under pressure.

Important Parameters:

Quality Checks:

• Weld should be uniform, without cracks or voids.
• Cross-section at weld should be at least equal to bar diameter.
• Visual inspection and bend tests as per IS 9417.

flowchart LR
    A[Prepare Bar Ends] --> B[Clamp Bars]
    B --> C[Heat with Multi-nozzle Burner]
    C --> D[Apply Axial Pressure]
    D --> E[Forge Weld Joint]
    E --> F[Cool Under Pressure]
    F --> G[Inspect Weld Quality]

This process ensures a solid phase, ductile joint suitable for reinforcing bars per IS 9417.