8/13/2019 Helical Compression Spring Design

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Essential Input Data

Additional Input Data

Standard Values

Calculated Values

Description Nomenclature Value Unit

Wire Diameter d 1.778 mm

Inside diameter Di 9.982 mm

Mean diameter Dm 11.76 mm

Outside diameter Do 13.538 mm

Deflection corresponding to load F f 0.607 mm

Deflection per coil ( From Tablle 163-CMTI) f'' 0.879 mm

Load on the spring corresponding to lengths L F 2.49 kgf

Maximum permissible Load From Table 163-CMTI Fn 8.909 kgf

Acceleration due to gravity g 9800 mm/sec2

Modulas of rigidity G 8100 kgf/mm2

Difference between two spring lengths h 1 mm

Number of working coils if 4.2

Total number of coils it 6.2

Stress concentration factor ( From table 162- CMTI) k 1.22

Free length of spring Lo 16.0934 mm

Clearance factor ( From Chart 118 -CMTI ) x 0.15

Tensile strength (From IS 4454) u 200 kgf/mm2

Maximum allowable shear stress ( From table 161-CMTI) a 94.5 kgf/mm2

HELICAL COMPRESSION SPRING

SPRING DESIGN INPUT

8/13/2019 Helical Compression Spring Design

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Description Nomenclature Value Unit

Wire diameter d 1.778 mm

Mean diameter Dm 11.76 mm

Outside diameter Do 13.538 mmm

Inside Diameter Di 9.982 mm

Hole diameter (For guided springs) minimum 14.2149 mm

Mandrel diameter (For guided springs) maximum 9.4829 mm

Condition for guiding of spring No need to guide

Spring index or coil ratio w 6.614173228

Stress concentration factor k 1.213158778

Spring Rate c 1.481326536 kgf/mm

Specific deflection 0.675070604 mm/kgf

Number of working coils if 4.2 Nos.

Load on the spring F 2.49 Kgf

Deflection of the spring corresponding to load F f 1.680925805 mm

Ultimate tensile strength of wire (Selected from IS:4454) u 200 Kgf/mm2

Maximum allowable shear stress (From Table 161) a 100 kgf/mm2

Modulus of rigidity of spring (Selected from Table165) G 8100 Kg/mm2

Uncorrected shear stress at load F 13.27308079 kg.mm2

Corrected shear stress at load F k 16.10235447 kgf/mm2

Average work done A 0.755715 kgfmm

Solid length of spring (All coils closed) Ls 11.0236 mm

Total Number of coils it 6.2 Nos.

Sum of minimum clearance between working coils at max. permissible load a 1.12014 mm

Minimum permissible test length Ln 12.14374 mm

Max. deflection corresponding to max load Fn fn 6.014204014 mm

Free length of the spring Lo 18.15794401 mm

Load on the Spring at any length F 23.83958048 Kgf

Deflection/unit length f'' 0.14452381 mm

Developed length of wire l 194.4536328 mm

Natural frequency of spring guided at ends nR 1096.008444 Hz

Acceleration due to gravity g 9800 mm/sec2

Specific weight of spring material y 0.00000785 kgf/mm3

SPRING DESIGN OUTPUT