Why Beryllium Copper?

High Strength & Elastic Modulus

• Beryllium copper alloys can attain high strengths through precipitation hardening.
• The strength of these alloys allow for the design of smaller, lighter components that can endure high bending stresses when used as a spring material.

High Fatigue Strength

• Beryllium copper exhibits excellent resistance to fatigue under reverse bending (up to 45 ksi) which qualifies its use in applications where other alloys fail to provide the same level of reliability.
• Applications include various springs, electrical switches, diaphragms, and connectors.

Elevated Temperature Properties and Resistance to Stress Relaxation

• Beryllium copper is a precipitation hardening alloy with excellent properties at elevated temperatures and can be used in a wide range of temperatures with little loss of mechanical properties.

Good Formability

• Beryllium copper alloys can be formed into complicated shapes in an annealed or cold-worked temper.
• The highest mechanical properties, commonly known as peak properties, can be obtained with proper heat treatment after forming.

High Electrical Conductivity

• The electrical conductivity of beryllium copper ranges from 16 to 65% IACS, depending on alloy and temper.
• Beryllium copper is the material of choice for high current density springs requiring low heat generation, due to the alloy's combination of high electrical conductivity, thermal conductivity, and strength.

Corrosion Resistance

• Beryllium copper has good corrosion resistance.
• Nearly equal to nickel silver.
• Not susceptible to hydrogen embrittlement.

Reliability

• Beryllium copper alloys possess all of the characteristics listed above, at the same time:
• There is no need for trading-off one property to satisfy another.
  
• Beryllium copper allows an engineer to employ a unique design approach when other materials will not perform.
• This is an important aspect for designers looking to miniaturize, yet not compromise, their component integrity.

Spring Properties and Miniaturization

• Beryllium copper alloys have high mechanical strength and a favorable elastic modulus, which makes them highly suitable as a spring material.
• The elastic modulus is usually the modulus of longitudinal elasticity, and is also known as Young's modulus. This value is obtained from the slope of strain against stress measured by a tensile test. In addition to the above test, the elastic modulus can be measured directly for flat springs.
• The elastic modulus is an important constant for the design of moving parts for connectors and switches.
• In general, if this value is too large, the contact pressure varies greatly with the slight movement of the contact. If this value is too small, the required contact pressure cannot be obtained.
• Since the YS/Young's modulus of beryllium copper is larger than that of stainless steels and phosphor bronze, a large displacement and a high contact pressure can be obtained.
• By fully utilizing such properties of beryllium copper alloys, the size of a part with the same spring pressure can be reduced if it is made of beryllium copper alloys compared with phosphor bronze.
• Molds or terminals around moving parts can be downsized, leading to the reduction of total product costs.
• Since beryllium copper has a mechanical strength as high as 1,500 N/mm2, approximately 220 ksi, the use of beryllium copper makes the pin pitch smaller, and even a connector of the same size and shape can be designed to higher density, reducing the cost per pin compared with phosphor bronze.
• The use of beryllium copper in jacks enables the reduction of size and weight. This decreases the amount of materials used and reduces costs for plating.
• When the total costs are compared, the use of beryllium copper is beneficial over the use of phosphor bronze.