Copper C10100 vs C11000 vs C101, What’s the Difference?

Copper, with its excellent electrical and thermal conductivity, corrosion resistance, and ductility, has long been a cornerstone material in various industries. However, not all copper is created equal. When it comes to high-performance applications, the choice of copper alloy can make a significant difference. In this article, we will delve into the differences between copper alloy C10100, C11000, and C101.

C10100 Copper vs C11000 vs C101 Comparison Guide

Two of the most commonly discussed copper alloys are C10100 (also known as C101 or Oxygen-Free Electronic Copper) and C11000 (Electrolytic Tough Pitch Copper). Each alloy has its unique properties and ideal applications, and understanding these differences is crucial for making informed material selection decisions. We will explore their compositions, key properties, typical applications, and the advantages and disadvantages of each. By the end, you will have a clear understanding of which copper alloy might be better suited for your particular needs, whether you are working on high-precision electronics, general electrical systems, or other demanding applications. Let’s begin by taking a closer look at each alloy and what sets them apart.

Mechanical, Thermal & Electrical Properties of Copper 10100, 11000 & 101

1. Mechanical Properties

Property	C10100 (C101)	C11000 (C110)	C101 Copper (Equivalent to C10100)
Tensile Strength	200–250 MPa (Annealed)	210–250 MPa (Annealed)	200–250 MPa (Annealed)
Yield Strength	33–69 MPa (Annealed)	69 MPa (Annealed)	33–69 MPa (Annealed)
Elongation	~45%	~45%	~45%
Hardness (Brinell)	50–60 HB	45–55 HB	50–60 HB
Modulus of Elasticity	110 GPa	110 GPa	110 GPa
Machinability	Poor to Fair	Fair	Poor to Fair

2. Thermal Properties

Property	C10100 (C101)	C11000 (C110)	C101 Copper (Equivalent to C10100)
Thermal Conductivity	391–400 W/m·K at 20°C	385–390 W/m·K at 20°C	391–400 W/m·K at 20°C
Specific Heat Capacity	~0.385 J/g·K	~0.385 J/g·K	~0.385 J/g·K
Melting Point	1,083°C (1,981°F)	1,083°C (1,981°F)	1,083°C (1,981°F)
Coefficient of Thermal Expansion	~16.5 µm/m·°C	~16.5 µm/m·°C	~16.5 µm/m·°C

3. Electrical Properties

Property	C10100 (C101)	C11000 (C110)	C101 Copper (Equivalent to C10100)
Electrical Conductivity	Up to 101% IACS	~100% IACS	Up to 101% IACS
Resistivity	~0.00000000175 ohm·m (at 20°C)	~0.00000000178 ohm·m (at 20°C)	~0.00000000175 ohm·m (at 20°C)
Voltage Rating	High	High	High
Current Carrying Capacity	Excellent for high current applications	Good for general electrical applications	Excellent for high current applications

Copper C10100, C11000 & C101 Equivalent

Copper C10100 Equivalent

C10100 (Oxygen-Free Electronic Copper – OFE) is a high-purity copper grade containing a minimum of 99.99% copper with extremely low oxygen content (typically less than 5 ppm). It offers exceptional electrical and thermal conductivity (approximately 101% IACS) and is ideal for critical applications requiring high reliability in vacuum, cryogenic, and electronic systems. C10100 is equivalent to CW009A (EN/DIN), C101 (BS), C1020 (JIS), and Cu-OF (ISO), and complies with several ASTM standards such as B170 and B152. Its purity and conductivity make it the preferred choice for high-end electrical and electronic components.

Copper C11000 Equivalent

C11000 (Electrolytic Tough Pitch Copper – ETP) is the most widely used commercial copper, featuring a copper content of 99.90% with a small amount of oxygen (~0.02–0.04%). It delivers excellent electrical conductivity (~100% IACS) and is widely used for wiring, busbars, motors, plumbing, and architectural elements. C11000 is the equivalent of CW004A (EN), C1100 (JIS), and Cu-ETP (ISO). In British Standards, C101 may also refer to this grade depending on context, although it more commonly aligns with oxygen-free variants. Its balance of performance, workability, and cost makes it ideal for general electrical applications.

Copper C101 Equivalent

C101 (British Standard) refers to high-conductivity copper under UK specifications and typically aligns with oxygen-free grades like C10100 (UNS) or CW009A (EN). It’s often used in situations that require superior electrical performance and ductility, such as electrical conductors, waveguides, or vacuum components. However, it’s important to note that “C101” in the UK may also refer to ETP copper (C11000 equivalent) depending on the supplier, which can cause confusion. Always check the material spec sheet or oxygen content to distinguish between the oxygen-free and ETP versions.

Copper C10100, C11000 & C101 Material Properties

Copper C10100 Properties

• UNS Designation: C10100
• Purity: 99.99% Cu (minimum)
• Oxygen Content: < 0.0005%
• Electrical Conductivity: ~101% IACS
• Thermal Conductivity: ~391 W/m·K
• Tensile Strength: ~220–360 MPa (annealed to hard drawn)
• Yield Strength: ~60–290 MPa
• Elongation: ~30–3%
• Hardness (HV): ~40–110
• Density: 8.94 g/cm³
• Applications: High-vacuum devices, superconductors, semiconductors, radio frequency applications

Copper C11000 Properties

• UNS Designation: C11000
• Purity: 99.90% Cu (minimum)
• Oxygen Content: ~0.02–0.04%
• Electrical Conductivity: ~100% IACS
• Thermal Conductivity: ~390 W/m·K
• Tensile Strength: ~210–360 MPa
• Yield Strength: ~60–300 MPa
• Elongation: ~30–5%
• Hardness (HV): ~45–110
• Density: 8.94 g/cm³
• Applications: Electrical wiring, power distribution, busbars, plumbing, roofing

Compositions of C10100, C11000 & C101 Copper

1. C10100 (C101) Copper Composition:

• Copper (Cu): 99.99% (min)
• Oxygen (O): 0.0005% (max)
• Other elements: Trace amounts of impurities (e.g., Fe, Pb, Zn, Ag, etc.), typically <0.001% each.

C10100 (C101) is essentially oxygen-free copper with an ultra-high purity. The oxygen content is extremely low, making it suitable for applications where electrical conductivity and corrosion resistance are critical.

2. C11000 (C110) Copper Composition:

• Copper (Cu): 99.90% (min)
• Oxygen (O): 0.02–0.04%
• Other elements: Trace impurities (e.g., Fe, Pb, Zn, Ag, etc.), typically <0.05% each.

C11000 (C110) contains a small amount of oxygen (around 0.02–0.04%), which is added during the manufacturing process. This is what distinguishes C11000 from the oxygen-free copper alloys like C10100. The presence of oxygen enhances certain properties, like workability and cost, but may also reduce its performance in certain sensitive applications.

3. C101 Copper (Equivalent to C10100):

• Copper (Cu): 99.99% (min)
• Oxygen (O): 0.0005% (max)
• Other elements: Trace impurities (e.g., Fe, Pb, Zn, Ag, etc.), typically <0.001% each.

C101 Copper is functionally equivalent to C10100 and has the same composition with high purity and virtually no oxygen. This composition is crucial for electrical and thermal conductivity and resistance to corrosion.

Copper 101 vs 110 Electrical Conductivity

Property	C101 (Oxygen-Free Copper / OFE / C10100)	C110 (ETP Copper / C11000)
Purity	≥ 99.99 % Cu (essentially oxygen-free, ≤ 0.0005 %)	~ 99.90 % Cu (contains 0.02–0.04 % oxygen)
IACS Rating (International Annealed Copper Standard)	101 % IACS (≈ 58.0 MS/m)	100 % IACS (≈ 57.5 MS/m)
Resistivity (20 °C)	1.68 × 10⁻⁸ Ω·m	1.72 × 10⁻⁸ Ω·m
Comments	Ultra-pure, highest conductivity available for industrial copper; used in high-frequency, vacuum, or cryogenic systems.	Slightly lower due to trace oxygen, but still the standard for electrical wiring and conductors.

C101 conducts electricity about 1 % better than C110. In most wiring or power transmission, that difference is negligible — but in precision electronics, vacuum, or cryogenic applications, it can matter.

Copper 101 vs 110 Thermal Conductivity

Property	C101 (Oxygen-Free Copper / OFE / C10100)	C110 (ETP Copper / C11000)
Purity	≥ 99.99 % Cu (essentially oxygen-free, ≤ 0.0005 %)	~ 99.90 % Cu (contains 0.02–0.04 % oxygen)
IACS Rating (International Annealed Copper Standard)	101 % IACS (≈ 58.0 MS/m)	100 % IACS (≈ 57.5 MS/m)
Resistivity (20 °C)	1.68 × 10⁻⁸ Ω·m	1.72 × 10⁻⁸ Ω·m
Comments	Ultra-pure, highest conductivity available for industrial copper; used in high-frequency, vacuum, or cryogenic systems.	Slightly lower due to trace oxygen, but still the standard for electrical wiring and conductors.

Copper C10100 vs C11000, Which is Better?

Copper C10100 (C101) – Oxygen-Free Electronic Copper:
Purity: ≥99.99% copper, with extremely low oxygen content (≤0.0005%), making it ideal for sensitive applications.
Electrical Conductivity: Slightly better than C11000, up to 101% IACS, making it highly effective in high-performance electronic and vacuum environments.
Applications: Primarily used in aerospace, semiconductor manufacturing, high-frequency systems, and cryogenic systems where purity and conductivity are critical.
Advantages: Superior in environments where oxygen could cause embrittlement, such as vacuum tubes and electronics.
Disadvantages: Higher cost and poor machinability, making it less suitable for large-scale, cost-sensitive projects.
Copper C11000 (C110) – Electrolytic Tough Pitch Copper:
Purity: ~99.90% copper, with small amounts of oxygen (~0.02–0.04%).
Electrical Conductivity: Around 100% IACS, slightly lower than C101, but still excellent for most general electrical applications.

Applications: Widely used in electrical wiring, busbars, motors, plumbing, and industrial applications where cost-effectiveness is important but high purity is not as critical.

Advantages: More affordable and widely available, making it a popular choice for general-purpose electrical applications.

Disadvantages: The oxygen content may limit its use in certain environments, such as vacuum systems or areas where high purity is essential.

Copper C10100 vs C101, Which is Better?

Copper C10100 and Copper C101 are essentially the same material; C10100 is the official UNS (Unified Numbering System) designation for Copper 101, also known as Oxygen-Free Electronic Copper (OFE). The terms C10100 and C101 both refer to the same high-purity copper alloy with a minimum purity of 99.99% copper and very low oxygen content (typically less than 0.0005%).

Therefore, there is no difference in quality, performance, or suitability between the two. The designation C10100 is simply a more formal or specific way to reference this particular alloy, often used in official standards or specifications.

C101 vs C110, What’s the Difference?

What is the difference between copper 110 and 101? If your application demands extremely high purity, minimal contamination (e.g. vacuum tubes, high-frequency signal lines, cryogenic systems), C101 is often preferred despite higher cost and more challenging machining. If you need a balance of excellent conductivity, easier fabrication, lower cost, and less sensitivity to process conditions, C110 is usually the go-to in “everyday” high-conductivity copper uses.

In many real-world electrical applications, the slight conductivity advantage of C101 may not justify its higher cost and lower machinability, so C110 is often “good enough.”

Copper C11000 vs C101, Which is Better?

Copper C11000 (C110) and Copper C10100 (C101) are both high-conductivity copper alloys, but they differ slightly in their composition and the types of applications they are suited for. Here’s a comparison to help determine which might be better depending on the specific needs:
Copper C11000 (C110) – Electrolytic Tough Pitch Copper:
Purity: ~99.90% copper, with 0.02–0.04% oxygen.
Electrical Conductivity: Around 100% IACS (International Annealed Copper Standard), making it ideal for general electrical applications.
Applications: Widely used in electrical wiring, busbars, motors, plumbing, and general industrial applications.
Advantages: More cost-effective and easily available. Great for general-purpose electrical conductors where extremely high purity is not required.
Disadvantages: The presence of oxygen can cause issues in specific applications like high-vacuum systems, high-frequency electronics, or environments where hydrogen embrittlement is a concern.

Copper C10100 (C101) – Oxygen-Free Electronic Copper:
Purity: ≥99.99% copper, with ≤0.0005% oxygen (virtually oxygen-free).
Electrical Conductivity: Slightly better than C110, up to 101% IACS, ideal for high-performance applications.
Applications: Used in high-frequency electronics, vacuum tubes, semiconductor equipment, cryogenic systems, and aerospace industries where pure copper is required to avoid embrittlement caused by oxygen.
Advantages: Superior conductivity and corrosion resistance due to ultra-high purity. Ideal for critical applications where high electrical or thermal performance is essential.
Disadvantages: Higher cost and poor machinability due to its softness and the absence of additives that would improve its machinability.

The Differences Between C10100, C11000 & C101 Copper

C10100, C11000, and C101 are three types of high-conductivity copper alloys, but they differ in their purity, oxygen content, and typical applications. Here’s a breakdown of their key differences:

Property	C10100 (C101)	C11000 (C110)	C101 Copper (Equivalent to C10100)
UNS Designation	C10100	C11000	C10100 (Oxygen-Free Electronic Copper)
Purity	≥99.99% Copper	~99.90% Copper	≥99.99% Copper
Oxygen Content	≤0.0005% (Oxygen-free)	~0.02–0.04%	≤0.0005% (Oxygen-free)
Electrical Conductivity	Up to 101% IACS	~100% IACS	Up to 101% IACS
Thermal Conductivity	391–400 W/m·K	385–390 W/m·K	391–400 W/m·K
Applications	Electronics, aerospace, cryogenics, high-frequency systems, vacuum tubes, semiconductors	Electrical wiring, busbars, motors, plumbing, general electrical applications	Same as C10100
Machinability	Poor to fair	Fair	Poor to fair
Corrosion Resistance	Excellent	Good	Excellent
Weldability	Not recommended (can lose oxygen-free quality)	Good	Not recommended (can lose oxygen-free quality)
Cost	Higher	Lower	Higher
Primary Advantage	Superior conductivity and purity for sensitive applications	Cost-effective with good conductivity for general-purpose use	Superior conductivity and purity for sensitive applications