Our alloys
C17200
The Reference Beryllium Copper Alloy
The C17200 alloy, also known as CuBe2 (Berylco 25 or B25), is by far the most widely used alloy in the Berylco range — across all product forms: strip, rod, wire, and other items. It contains 2% beryllium in a copper matrix.
Properties
The C17200 alloy (Berylco 25 or B25) achieves the highest mechanical strength and hardness levels of any copper alloy after age hardening (up to 1500 MPa). C17200 (B25) is also available in the mill-hardened condition. Using the material in the mill-hardened temper eliminates the need for a subsequent age hardening heat treatment, removing the risk of distortion in finished parts and reducing production costs. The C17200 alloy (B25) offers unique combinations of mechanical and electrical properties, along with good formability in the annealed and lightly cold-worked conditions. It also stands out for its high fatigue strength and excellent stress relaxation resistance.
Equivalent Standards
| Standard | Numbering System | Designation |
| ASTM | UNS | C17200 |
| ISO / AFNOR / DIN | ISO | CuBe2 |
| BS | EN | CW101C |
| NGK | Berylco | Berylco 25 (B25) |
Applications
Its unique combination of properties makes this alloy an essential material across a wide range of applications.
Our Products
C17200 (B25) is available in all product forms: strip, rod, wire, plate, chill vents, and other items.
Strips
Our beryllium copper alloys are available in strip form. We offer tailor-made solutions to meet your specific requirements in terms of width, thickness, hardness, and temper.
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Rods
Our beryllium copper alloys are available in rod form. We supply custom dimensions based on your needs, including length, diameter, hardness, and material temper.
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Wires
Our beryllium copper alloys are available in wire form. We provide customized products to match your specifications for length, diameter, hardness, and temper.
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Plates / Blocks
Our beryllium copper alloys are available in plate and block form. We deliver made-to-order solutions according to your required dimensions, hardness, and temper conditions.
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Why Choose NGK BERYLCO for C17200
Choosing NGK Berylco means choosing:
- The European leader in beryllium copper alloys, with over fifty years of expertise.
- A French manufacturer based in France, supported by local partners across Europe through its subsidiaries in Germany and the United Kingdom, and its long-established distributors in Italy, Spain, Poland, and Turkey.
- A solid, reliable supplier belonging to a century-old industrial group, NGK Corporation, headquartered in Japan with a global presence.
- A certified supplier, committed to product quality, environmental responsibility, and operator safety.
Beyond our technical expertise, choosing us means actively supporting French and European industrial sovereignty.
FAQ (Frequently Asked Questions)
The C17300 alloy (CuBe2Pb) is a lead-bearing variant of C17200. The addition of lead significantly increases the machinability rating to 60%, compared to approximately 20% for C17200 (CuBe2).
C17300 (Berylco 33/25) is available in rod form only, in various diameters (up to 28 mm), for screw-machining and turning applications.
C17200 is designated CuBe2 under the ISO standard. It is the same alloy, referred to differently depending on the standard used. In our product range, this alloy is Berylco 25 (abbreviated B25).
The conductivity of C17200 ranges from 15 to 23% IACS (International Annealed Copper Standard), depending on the temper condition — whether hardened, heat-treated, or as-rolled. Please refer to our catalog for the electrical conductivity values of our alloys by temper condition.
C17200 is non-magnetic, as are all Berylco beryllium copper alloys.
The C17200 alloy (Berylco 25) is available in approximately forty different temper conditions, as follows:
| Temper | Meaning | Description |
| A | Annealed | Solution-annealed, soft condition. No cold work, no thickness reduction. |
| H | Hard | Cold-worked condition. Thickness reduced by 37% (maximum achievable). The harder the material, the more difficult it is to form. |
| 1/2 H | Half Hard | Cold-worked condition. Thickness reduced by 19%. |
| 1/4 H | Quarter Hard | Cold-worked condition. Thickness reduced by 10%. |
| M | Mill-Hardened | Pre-aged under controlled conditions at the mill. |
| T | Treated | Age-hardened condition, either at our facility or by the customer. |
| S B | NGK-proprietary designations | Special tempers produced at our facility through controlled grain refinement, improving fatigue resistance and formability. |
Tempers incorporating cold work, heat treatment, and high-formability mill-hardened conditions are available. The choice of temper will depend on the target properties and forming constraints.
Please refer to our catalog for the full range of temper conditions offered by NGK Berylco France. Our experts are available to advise you.