OVERVIEW

Springs and die springs are important mechanical components used in countless mechanisms, mechanical systems, and tooling applications. This chapter contains data and calculation procedures that are used to design springs and that also allow the machinist, toolmaker or tool engineer, metalworker, and designer to measure an existing spring and determine its spring rate. In most applications, normal spring materials are spring steel or music wire, while other applications require stainless steel, high-alloy steels, or beryllium-copper alloys. The main applications contained in this chapter apply to helical compression die springs and standard springs using round, square, and rectangular spring wire. Included are compression, extension, torsion, and flat or bowed spring equations used in design, specification, and replacement applications. Figure 10.1 shows some typical types of springs.

Material Selection. It is important to adhere to proper procedures and design considerations when designing springs.

Economy. Will economical materials such as ASTM A-229 wire suffice for the intended application?

Corrosion Resistance. If the spring is used in a corrosive environment, you may select materials such as 17-7 PH stainless steel or the other stainless steels, i.e., 301, 302, 303, 304, etc.

Electrical Conductivity. If you require the spring to carry an electric current, materials such as beryllium copper and phosphor bronze are available.

Temperature Range. Whereas low temperatures induced by weather are seldom a consideration, high-temperature applications call for materials such as 301 and 302 stainless steel, nickel-chrome A-286, 17-7 PH, Inconel 600, and Inconel X750. Design...