COMPREHENSIVE TECHNICAL ANALYSIS AND DATASHEET OF UNS C11000 ELECTROLYTIC TOUGH PITCH COPPER FASTENERS
UNS C11000 (Electrolytic Tough Pitch - ETP) is the most widely used grade of commercially pure copper, globally recognized for its extremely high electrical and thermal conductivity. Containing a minimum of 99.90% pure copper with a highly controlled and dispersed oxygen content, C11000 fasteners form the critical backbone of high-amperage electrical, power transmission, and heavy-duty grounding applications.
Beyond its benchmark 101% IACS (International Annealed Copper Standard) conductivity, C11000 provides excellent atmospheric corrosion resistance and outstanding ductility. These specialized fasteners are designed specifically to ensure absolute minimal electrical resistance across mechanical joints, making them indispensable in switchgears, busbars, and complex telecommunication infrastructures where power loss must be mitigated.
■ Product Overview & Specifications
| Material Classification | Electrolytic Tough Pitch (ETP) Copper |
|---|---|
| UNS Designation | C11000 |
| Microstructure | Single-phase Alpha Copper (with cuprous oxide dispersion) |
| Magnetic State | Completely Non-Magnetic |
| Density | 8.89 g/cm³ (0.321 lb/in³) |
| Size Range | Metric: M3 to M36 | Imperial: 1/8" to 1-1/2" |
| Primary Attribute | Maximum Electrical Conductivity (101% IACS) |
■ Proprietary Datasheet Download (GATED)
UNS C11000 ETP Copper — Complete Technical Datasheet
Contains detailed electrical resistance parameters, current-carrying capacities for specific fastener diameters, and critical low-torque installation guidelines to prevent thread yielding in soft copper assemblies.
⬇ DOWNLOAD DATASHEET■ MTC Integration Section
Integrity in electrical fastening systems is paramount to prevent catastrophic arching and thermal failure. Every lot of C11000 copper shipped by Ananka is accompanied by rigorous, fully authenticated documentation mapping back to the primary smelting facility.
- EN 10204 Type 3.1: Issued by our independent quality department, providing precise copper purity levels, verified electrical conductivity testing (IACS validation), and mechanical temper checks.
- EN 10204 Type 3.2: Facilitated upon request for heavily regulated power-generation projects requiring third-party witness testing.
■ Chemical Composition
The C11000 specification strictly dictates a minimum of 99.90% Copper (including trace Silver). The deliberate, controlled presence of Oxygen (~0.02% to 0.04%) defines it as "Tough Pitch," which serves to scavenge trace impurities from the melt that would otherwise drastically reduce the metal's electrical conductivity.
| Copper (Cu) + Silver (Ag) | Oxygen (O) | Lead (Pb) | Iron (Fe) | Antimony (Sb) | Bismuth (Bi) | Total Other Impurities |
|---|---|---|---|---|---|---|
| 99.90 Min | ~0.02 – 0.04 (Typical) | 0.005 Max | 0.005 Max | 0.002 Max | 0.001 Max | 0.03 Max |
■ Mechanical Properties
| Mechanical Property | Annealed Temper (Soft) | Hard Drawn Temper (Typical Fastener) |
|---|---|---|
| Tensile Strength | 32,000 psi (220 MPa) | 45,000 - 55,000 psi (310 - 380 MPa) |
| Yield Strength | 10,000 psi (69 MPa) | 40,000 - 48,000 psi (275 - 330 MPa) |
| Elongation (in 2 inches) | ~45% | ~5 - 15% |
| Hardness (Rockwell F) | 40 HRF | 80 - 90 HRF |
■ Equivalent Grades & Designations
| Standard / System | Designation |
|---|---|
| ASTM Specifications | ASTM B187 (Bus Bar), ASTM B152 (Sheet/Strip) |
| Common Trade Names | ETP Copper, Tough Pitch Copper, 110 Copper |
| European Equivalent | EN CW004A / Cu-ETP (DIN 2.0060) |
| British Standard (BS) | C101 / C102 |
■ Applications & Industries
- Electrical Power Generation & Distribution: Primary fastening hardware for busbars, transformers, switchgears, and heavy-duty circuit breakers.
- Grounding Systems: Direct burial grounding rods, grounding plates, and lightning protection systems where high corrosion resistance in soil is required.
- Telecommunications & RF: Coaxial connectors, wave guides, and large-scale transmission antennae where signal loss is unacceptable.
■ Compatible Fastener Assemblies
| Mating Bolts/Studs | Internal Threads (Nuts) | Washers |
|---|---|---|
| C11000 ETP Hex Bolts & Studs | C11000 ETP Finished Hex Nuts | C11000 Flat Washers / Phosphor Bronze Lock Washers |
■ Torque & Installation Guidelines
CRITICAL WARNING: C11000 Copper is a highly ductile, relatively soft metal compared to standard steel alloys. Applying standard steel torque values will result in immediate thread stripping, elongation, and joint failure. Torque must be strictly managed, and Belleville (conical) washers are often recommended to maintain clamping force during thermal cycling.
| Nominal Diameter | Threads Per Inch (UNC) | Max Target Torque (in-lbs) | Max Target Torque (ft-lbs) |
|---|---|---|---|
| 1/4" | 20 | 45 - 50 | ~ 4 |
| 5/16" | 18 | 90 - 100 | ~ 8 |
| 3/8" | 16 | 160 - 180 | ~ 14 |
| 1/2" | 13 | 380 - 400 | ~ 32 |
■ Frequently Asked Questions
1. What exactly does "Tough Pitch" mean?
In copper metallurgy, "Tough Pitch" refers to the deliberate retention of a very small amount of oxygen (usually around 0.02% to 0.04%) during the refining process. This trace oxygen reacts with and isolates other remaining impurities (like bismuth or antimony) into harmless oxides. If these impurities were left free, they would severely reduce the electrical conductivity of the copper.
2. Why use C11000 fasteners instead of stronger Brass or Bronze?
While alloys like Silicon Bronze or Naval Brass offer significantly higher tensile strength, they suffer massive drops in electrical conductivity due to their alloying elements. For example, standard brass possesses only about 28% IACS conductivity, whereas C11000 guarantees 101% IACS. In high-amperage electrical joints, using a brass bolt instead of a copper one creates resistance, generating dangerous excess heat.
3. Is there a risk of galvanic corrosion when using C11000?
Yes. Copper is a highly noble (cathodic) metal. If C11000 fasteners are directly mated to more active (anodic) metals like aluminum or zinc-plated steel in the presence of an electrolyte (like moisture), the active metal will rapidly corrode. When securing aluminum busbars, transition plates or specialized tin-plated copper fasteners must be used to mitigate the galvanic reaction.
