Beryllium Copper - RWMA Class 3 and 4 Copper - Alloys 17510 & 17200
Beryllium Copper Applications
- Resistance Welding
- Plastic Injection Mold tooling
- Oil & Gas
- Electronics & Telecommunications
- Foundry Products
Beryllium Copper Information
The amount of beryllium in beryllium copper alloys does not exceed 1/50th of the total alloy and is not less than 4/10ths of a percent. The percentage of beryllium in the copper makes these alloys' strength comparable to high alloy steel. Beryllium copper alloys have features that include the fact that they are great conductors of temperature and are resistant to stress relaxation. Class 3 beryllium copper is a much better conductor than that of its class 4 counterpart. On the other hand, class 4 beryllium copper is much stronger than that of its class 3 counterpart. Other titles for beryllium copper include spring copper and beryllium bronze.
Class Three Beryllium Copper - Alloy 17510
- ASTM B441
- ASTM B534
- MIL C-81021
- SAE J461
- SAE J463
- UNS C17510
- Class 3 Copper
Class 3 Alloy is specifically recommended for projection welding dies, flash and butt welding dies, current carrying shafts and bushings. As castings, Class 3 Alloy (having higher strength than Class 2), is recommended for highly stressed welder structural current carrying members and heavy duty offset electrode holders.
Class 3 Alloy is generally recommended for spot welding and seam welding steels having high electrical resistance, such as stainless steels. The Class 3 Alloy is heat treatable.
Its most common uses are in those applications that necessitate a lot of conductivity of temperature or electricity. Its ultimate tensile strength is 140 ksi while its hardness is RB 100. The conductivity of C17510 is about 45-60% of regular copper.
Class Four Beryllium Copper - Alloy 17200
- AMS 4651
- AMS 4725
- ASTM B194
- ASTM B196
- ASTM B197
- ASTM B570
- MIL C-21657
- SAE J461
- SAE J463
- UNS C17200
- Class 4 Copper
Class 4 Alloy has extremely high hardness and ultimate tensile strength although the electrical conductivity is lower than the Class 3 Alloy
Class 4 Beryllium Copper (17200) is available in heat treatable tempers. Alloys are used in a wide range of applications requiring high strength and stiffness with good conductivity.
Typical uses include electrical/electronic connectors, current-carrying springs, precision screw machined parts, welding electrodes, bearings, plastic molds and corrosion resistant components.
Of all the beryllium copper alloys, the class 4 alloy is the most frequently used. Additonally, the strength and hardness of C17200 are very close to those of steel. When compared to commercial copper alloys, its strength and hardness are the closest.
|RWMA Class/(Temper)||Alloy Number||Hardness||Conductivity(%)||Tensile Strength|
|Class 3 (HT)||17510||B95-102||48-60||110-140 ksi|
|Class 4 (HT)||17200||C38-44||22-28||180-220 ksi|
TB00 or A
This produces the softest form of the material. This is the condition or temper resulting from heating the material to a temperature sufficient to allow the beryllium to dissolve into a solid solution within the copper base metal, followed by rapid cooling.
Hardness (17510): B20-45
TF00 or AT
This process is often referred to as Aging, Age Hardening or Heat Treating. This is the condition or temper resulting from the application of a specific time and temperature combination. This action produces an extreme strengthening effect within the material. The tensile properties change from copper-like to steel-like and the thermal and electrical properties also increase. The specific combination of time and temperature applied determines the final properties.
Hardness (17510): B92-100
TD04 or H
In Beryllium Copper this means that the material is processed like the TB00/A temper material and then gets drawn through a die to make a shape. The extra drawing through the die makes the material harder.
Hardness (17510): B78-88
TH04 or HT
In Beryllium Copper this means that the material is carefully annealed and then cold drawn to a specific size and then heat treated.
Hardness (17510): B95-102