IS 191 : 2007Copper - Designation of Grades

IS 191 (2007) provides Copper — Designation of Grades — the IS code for copper material grading + composition used in electrical conductors, plumbing, roofing, decorative architecture + industrial applications.

Use when: specifying copper for electrical applications (cables, busbars, wire); plumbing (pipes, fittings); building (roofing, gutters); industrial (heat exchangers, condensers).

Copper grade designations (per IS 191):

1. Cu-CATH-1 (Cathode Copper, Grade 1): - Purity: 99.99 % Cu min - For: electrical conductors (premium); high-purity applications - Conductivity: 100 % IACS (International Annealed Copper Standard)

2. Cu-CATH-2 (Cathode Copper, Grade 2): - Purity: 99.95 % Cu min - For: electrical + general applications - Conductivity: 99 % IACS

3. Cu-FRTP / Cu-FRHC (Fire-Refined Tough Pitch): - Purity: 99.85 % Cu min - For: electrical conductors (most common) - Conductivity: 98-100 % IACS - Standard production grade

4. Cu-DLP (Phosphorus Deoxidized, Low Phosphorus): - For: heat exchanger tubes; aerospace - Conductivity: 95-98 % IACS

5. Cu-DHP (Phosphorus Deoxidized, High Phosphorus): - For: brazing + welding applications - Conductivity: 80-90 % IACS

Applications by grade: - High-conductivity (FRHC): transmission cables, busbars, transformers, motors - High-conductivity special (CATH-1): instrumentation, fine wires - DLP/DHP: chemical industry, heat exchangers, oxygen-rich environments - Brass / bronze (alloys): decorative, plumbing, hardware

Physical properties: - Density: 8.96 g/cm³ - Melting point: 1085 °C - Thermal expansion: 17 × 10⁻⁶ /°C - Tensile strength: 200-400 MPa (annealed); higher when work-hardened - Electrical conductivity: 58 MS/m (100 % IACS)

Conductivity benchmarks (IACS - International Annealed Copper Standard): - 100 % IACS = 58.0 MS/m at 20 °C - 98 % IACS = 56.8 MS/m (standard FRHC) - 95 % IACS = 55.1 MS/m (DLP)

Chemical composition (per IS 191): - CATH-1: Cu ≥ 99.99 %; Cu + Ag ≥ 99.95 % - FRHC: Cu ≥ 99.85 %; O ≤ 0.04 %; sulphur, selenium controlled - DLP: Cu ≥ 99.85 %; P 0.001-0.04 % - DHP: Cu ≥ 99.85 %; P 0.015-0.040 %

Mechanical properties (annealed): - Tensile strength: 200-260 MPa - Yield strength: 70-105 MPa - Elongation: 35-55 % - Hardness (Vickers): 50-80

Acceptance: - Composition per IS 191 - Conductivity per requirement - Mechanical properties per grade - Surface finish (electrical applications: smooth) - Dimensional tolerance per project specification

Common forms: - Wire / rod: electrical conductors - Sheet / plate: electrical busbars, decorative - Tube: plumbing, heat exchangers - Strip: transformer windings, busbars - Granules / powder: metallurgical applications

Service life: - Indoor electrical: 50+ years - Buried electrical: 30-50 years (with protection) - Outdoor electrical: 30-50 years (with periodic maintenance) - Plumbing: 30-50+ years - Heat exchanger: depends on fluid + temperature; 10-30 years

• IS 1897 — Copper Tubes for Plumbing.
• IS 9912 — Copper Sheet + Strip for Roofing.
• IS 12856 — Copper Wire for Communication Cables.
• IS 1554 — PVC Insulated Cables (with copper conductors).
• IS 10810 Part 1 — Copper Conductors for Insulated Cables.
• IS 10810 Part 2:1984 — Aluminium Conductors (alternative).
• IS 1024 — Copper Pipes + Tubes.
• IS 11468 — Brass + Bronze Castings.
• IS 14160 — Copper Alloys (Brass + Bronze).
• ASTM B 152 — Standard Specification for Copper Sheet, Strip, Plate, Rolled Bar.
• ASTM B 187 — Copper Bus Bars + Rods.
• ASTM B 49 — Copper Rod Drawing Stock for Electrical Use.
• IEC 60028 — Copper Conductors.
• ISO 1190 — Copper + Copper Alloy Compositions.
• Bureau of Indian Standards Metallurgy Manuals.

1. Wrong grade for application (low-purity in electrical) → high resistance + losses. 2. Surface oxidation not addressed → conductivity drop at terminations. 3. Mixed alloy connections without bi-metallic isolator → galvanic corrosion. 4. Quality not verified per batch → variable performance. 5. Cost-driven substitution → aluminium where copper specified. 6. Annealed copper used for high-mechanical-stress applications → fatigue failure. 7. No surface protection in outdoor exposure → patina + degradation. 8. Storage in damp / corrosive atmosphere → surface oxidation. 9. Mixed bus bar grades → resistance + heating differential.

1. Specification per IS 191 + application requirement. 2. Procurement from qualified manufacturer. 3. Quality acceptance (composition + conductivity + mechanical). 4. Installation per relevant code (IS 5613 for cables, IS 1042 plumbing). 5. Service: periodic visual inspection. 6. Long-term: copper has excellent service life with proper installation.

IS 191 is fundamental for India's electrical + plumbing + industrial copper usage.