To proceed with the design, initial values must be assumed. Typically, the type of material is initially selected. The objective of the design then becomes finding the geometry of the spring that can operate under the applied force and deflection. Wire dimensions, coil length, and the number of active coils are assumed initially for trial calculation. These values are correlated through tables and charts from spring design handbooks or manufacturer datasheets. The values are verified if the theoretical stress experienced by the spring with trial dimensions is within the maximum allowable stress of the material operating at a given type of service. If the theoretical stress calculated exceeds the maximum allowable stress, another set of trial dimensions is used. Cylindrical Springs: This is the most common type of spring. The pitch on these springs is equal. Since the pitch and coil diameters do not change along the length of the spring, the spring rate is constant. where: N is the number of active coils of the spring. Modifying this equation to obtain the spring rate (k) results in the equation, These are springs that are designed to deflect under compressive loads. They are the most commonly used and represent 80 to 90% of all springs manufactured. Compression springs geometries can be cylindrical, conical, convex, or concave.

Stainless steel is almost always cold worked, which can result in magnetism in the spring. This can be an issue in some devices, so it is important to specify or talk to us about whether you will need us to undertake extra work to achieve non-magnetic springs. F is the force, D is the coil diameter, lowercase d is the wire diameter, Kw is the Wahl correction factor, and C is the spring index (D/d).Flat Spring: The model for this type of spring is a flat beam supported either on one or both ends. When supported on one end, it is considered a cantilever spring. Its shape can be rectangular or tapered at the free end. With regards to the cross-section, the geometry is usually rectangular. The deflections for this type of spring are small, only about 25% of the spring length. Common applications of flat springs are electrical switches. Copper is known for being a fairly soft and ductile metal, which means that it isn’t nearly so suitable as stainless steel is for bearing heavy loads. On the other hand, when the spring also needs to carry an electrical charge, beryllium copper springs might be able to provide the impact strength and anti-corrosion properties that are just right for the product you have in mind. Flat springs are made of flat strip steel and are used in many applications and are ideally suited for applications where space is limited or where the spring can be used as part of mounting assembly. The flat spring design allows forming of specific features and profiles for a unique application and mounting location. Flat springs can be made in a variety of shape, sizes, designs and materials to work for many design applications. An experienced Lee Spring engineer knowledge in our fourslide, powerpress, and hand-forming tools can work with you from design concept through manufactured parts to assist with creating the optimal design of your custom flat spring.

Hard-Drawn MB Grade, ASTM A227 (0.60-0.70 percent carbon): This grade is used for general purpose springs where cost is the most important factor. Although increased use in recent years has resulted in improved quality, it is best not to use this grade where long life and accuracy of loads and deflections are important. It is available in diameters ranging from 0.031 to 0.500 inch and in some smaller and larger sizes also. The material is available in square sections but at reduced tensile strengths. It is readily plated. Applications should be limited to those in the temperature range of 0 to 250 °F. Barrel (Convex) and Barbell/Hourglass (Concave) Springs: These are helical springs with double cone geometries. They have the same advantages as that of conical springs.The spring‘s elongation distance (x) can be expressed as linear deflection (δ). The linear deflection can be derived from the angle of twist (θ) formula, Hard-drawn (ASTM 227): These are the cheapest of the spring materials, with inferior qualities compared to music wire and oil-tempered steels. Hard-drawn wires are also cold worked, similar to music wires, but the drawing process used is less controlled than that of music wires.

Primarily used in electrical applications, copper springs can be vital to your final product. Titanium Springs Extensive Network of Approved Suppliers (Raw Materials, Special Processes and Production Components)Closed and Square:The last coil of a closed and square compression spring is closed, making it possible to stand on end on a flat surface. The pitch of the end is reduced to form one dead coil. Phosphor Bronze (ASTM B159): Phosphor bronze is an alloy of copper, tin, and phosphorus. This is the most widely used copper-base spring alloy. It has good electrical conductivity coupled with the ability to withstand repeated bending. However, it is are not hardenable by heat treatment. A spring is a flexible machine element that stores mechanical energy when subjected to tensile, compressive, bending, or torsional forces. We are committed to the effective implementation of a Quality Management System satisfying the requirements of BS EN ISO 9001 and it's on going improvement. It is our goal to improve customer retention by achieving complete customer satisfaction through competitive pricing, unrivalled customer service, zero rejections and on time deliveries. Ability to Deliver where: T is the torque, L is the length of the wire, G is the shear modulus, and J is the polar moment of inertia of the wire cross-section. In terms of spring design variables, the linear deflection of a spring is expressed as,