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Technical DataSupplementary informationHow to Use Hexagon Socket Set Screws Shaft Diameter and Set Screw SizeThe impression of screw tip should clearly appear on the shaftcylinder surface. A correlation between non-tightening shaftdiameter and set screw is shown as below.Screw tip impressionGood example Bad exampleCorrelation between set screw and shaft diametershaft diameter [mm]605040302010(Example)Max. shaft diameterMin. shaft diameter3 4 5 6 8 10 12set screw diameter [mm] If the Size of Set Screw Cannot be EnlargedTwo set screws are sometimes used when a large shaft holdingpower is required. However, using two set screws does notnecessarily mean that the shaft holding power becomes double.This is because shaft holding power is different depending on theopen angle (alignment) between two set screws. The followingdiagram indicates the relationship between set screw open angleand shaft holding power.Set screw open angle and shaft holding powerMagnification of shaft holdingpower per set screw2.01.81.61.41.21.0 Shaft Diameter and Shaft Holding PowerThe fixation limit (shaft holding power) of shaft and hub or fl angeis related to the friction factor between the tip of set screw andshaft. The fixation limit based on the data of examination resultsis described below.Non-tightening shaft diameter and shaft holding power(concave point)Shaft holding power [N·cm]10,0005,0001,000500200M5 T = 441N·cmM3 T = 98N·cmM4 T = 216N·cm5 10 15 20 25 30 35Shaft diameter [mm]* Shaft holding power of set screw is related to the size of non-tightening shaft diameter. Hardness and Shaft Holding PowerShaft holding power decreases as hardness of non-tighteningshaft increases. The relationship between hardness and shaftholding power is described below.Set screw and shaft hardness and shaft holding powerDecreasing rate of shaft holding power1.00.5Set screw HRC40Set screw HRC5020 25 30 35 40 45 50 55 60Hardness of shaft [HRC]0 30 60 90 120 150 180Set screw open angle [ ° ]In the caseof one.Technicaldata108www.feyc.es