Flat SpiralSprings Meaning of Symbols The symbols used for spring design are shown in Table 1 below. The values of the longitudinal elastic modulus (E) are based on Table 2. Table 1. Symbols and units used in calculations Symbol Meaning of Symbol Unit E Longitudinal elastic modulus N/mm2 b Material width mm t Plate thickness mm l Total length mm M Moment N・mm k Spring constant N・mm/rad σ Stress N/mm2 Table 2.Longitudinal elastic modulus：E（N/m㎡） Material E Value Spring steel material 206×103 Stainless steel SUS302 SUS304(Correspond to X5CrNi18-9,1.4301,S30400) SUS631(Correspond to X7CrNiAl17-7,1.4568,S17700) 186×103 186×103 196×103 Nickel-silver wire 108×103 Phosphor bronze wire 98×103 Beryllium copper wire 127×103 Basic Calculation Formulas Used For Design … Continue reading Flat Spiral Springs: Calculation Formulas