Engineering
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SMALLEY Material Types Material Types Selecting the proper material for an application requires a general knowledge of what is commonly available for use in Smalley flat wire products. Specifying the correct material can prevent additional cost and failure in operation. Carbon steel is the most commonly specified material. Stainless steels, although more costly than carbon steel, provide far superior corrosion resistance and have higher temperature operating limits. Carbon Steel Oil Tempered SAE 1070-1090 high carbon tempered spring steel is a standard material for spiral retaining rings...

Super Alloys Inconel X-7501 This nickel-chromium alloy is used most commonly in high temperature and corrosive environments. Two commonly specified tempers of Inconel are described below. Most commonly, Inconel X-750 is precipitation heat treated to a spring temper condition. In this state, it has temperature resistance to 700°F. The National Association of Corrosion Engineers (NACE) approves this hard temper to specification MR-01-75 (Rc50 maximum) for spiral retaining rings and wave/compression springs. #1 temper, which requires a longer heat treatment than spring temper, has a lower...

SMALLEY Material Finishes Material Finishes Black Oxide MIL-DTL-13924, Class 1 This finish provides a flat black finish. Black oxide is intended more for cosmetic appearance than for corrosion resistance. Zinc Plating Zinc Plate, ASTM B633, Type V, Fe/Zn 5, SC1 (Colorless) Zinc Plate, ASTM B633, Type VI, Fe/Zn 5, SC1 (Colored Chromate) Zinc plating is used on carbon steel to increase the corrosion resistance of the product. Zinc plating is often used as a cost effective and ecologically friendly alternative to Cadmium plating. Our standard Zinc plating, Type V and Type VI, are RoHS...

Materials Specifications Ultimate Tensile Strength Federal, aerospace and other regulating agencies have prepared several specifications for sheet and strip materials, but few have been published for flat wire. Smalley procures its material to internally generated specifications. In addition to controlling tensile strength, rigid inspection procedures have been established to check for edge contour, physical imperfections, camber, crosssection and chemical composition. To check the spring properties of wire, Ultimate Tensile Strength is the preferred test method over hardness because spring...

Spring Design Spring Design Operating Environment Defining the Spring Requirements Although wave spring applications are extremely diverse, there is a consistently basic set of rules for defining spring requirements. Those requirements are used to select a stock/standard spring or design a special spring to meet the specifications. High temperature, dynamic loading (fatigue), a corrosive media or other unusual operating conditions must be considered in spring applications. Solutions to various environmental conditions typically require selection of the optimal raw material and operating...

Nomenclature b Radial Width of Material, in [(O.D. - I.D.H2] Dm Mean Diameter, in [(O.D. + I.D.)+2] E Modulus of Elasticity, psi K Multiple Wave Factor, see Table 1 L Length, Overall Linear, in N Number of Waves (per turn) Multiple Wave Factor (K) N 2.0-4.0 4.5-6.5 7.0-9.5 10.0 & Over Single Turn Gap or Overlap Type Applications 1. Low-Medium Force 2. Low-Medium Spring Rate 4. Precise Load/Deflection Characteristics Single turn wave springs are the basic and most common wave spring product. They are used in the widest variety of spring applications due to their lower...

SMALLEY Spring Design Crest-to-Crest (Series Stacked) Applications 2. Low-Medium Spring Rate 4. Precise Load/Deflection Characteristics Crest-to-Crest flat wire compression springs are pre-stacked in series, decreasing the spring rate by a factor related to the number of turns. Formulas: Deflection = f = PKD™Z * 1°^ E b t3 N4 O.D. Note: Operating Stress = S = 3n^^m N must be in 16 wave increments 4bt2N2 Z = Number of active turns Nested Spirawave® (Parallel Stacked) 1. Higher Force 2. Higher Spring Rate 4. Precise Load/Deflection Characteristics Nested Spirawave Wave Springs are pre-stacked...

Fatigue Stress Ratio = X = (refer to Table 2) Stress Operating Stress Compressing a wave spring creates bending stresses similar to a simple beam in bending. These compressive and tensile stresses limit the amount a spring can be compressed before it yields or "takes a set". Although spring set is sometimes not acceptable, load and deflection requirements will often drive the design to accept some set or "relaxation" over time. Maximum Design Stress Static Applications Smalley utilizes the Minimum Tensile Strength found in this catalog's Materials section to approximate yield strength due...

SMALLEY Spring Design Hysteresis Wave springs exert a greater force upon loading and lower force upon unloading. This effect is known as hysteresis. The shaded area shows a graphic representation between the curves in Figure 2. In a single turn spring, friction due to circumferential and radial movements are the prime causes. Crest-to-Crest and Nested Springs also contribute to the frictional loss HYSTERESIS as adjacent layers rub against each other. Sufficient lubrication will minimize Working Height (Inches) this effect Design Guidelines Material Cross-Section Material cross-section...

Engineering Support Engineering Design Spirolox Retaining Ring and Constant Section Ring applications, although diverse, can be ­ nalyzed with a a straight forward set of design calculations. There are four main areas that should be considered in most applications. 1. Material Selection 2. Load Capacity 3. Rotational Capacity 4. Installation Stress Smalley Application Engineers are available to provide immediate technical assistance. Spiral Wound in Multiple Turns Increases load capacity yet allows easy assembly by hand or as an automated process. The following pages of Spirolox Retaining...