Overview

• Compression spring is the most commonly used spring. It is easy to design, relatively simple and cheap to manufacture, and has higher efficiency. It has various shapes such as cylindrical, hourglass, barrel etc depending on the application

Application

• Components for automobile, electrical, electronic, stationery, toy, industry, and information - communication

Features

• Compression coil spring is typically cylindrical and manufactured by hot or cold coiling, and the material for compressing the load applied to the spring. Spring ends have different shape according to the types of load and the coil diameter depends on the size.

Symbols and formula used for compression spring design

1) Spring symbols

d	wire diameter	ai		arm length (mm)
Da	mean coil diameter	a2		arm length (mm)
Na	number of active coils	E
Nt	total number of coils	G
K	spring constant (kg / mm)	C		spring index (Da/d)
P	Load (kg)	G	SWP	8,200
d	deflection (operation angle) (mm)		SUS	7,500
Pj	initial tension		Phosphor bronze	450
Kt	arm spring constant (kg.mm/degree)	E	SWP	21,000
M	moment (kg.mm)		SUS	19,000
q	torsion angle		Phosphor bronze	11,000
K1	stress correction coefficient	P	SWP	7.85
Ke	arm spring stress correction coefficient		SUS	7.9
	torsion stress(kg/mm2)		brass	8.6
O'	bending stress (kg/mm2)		Geman silver	9.0
	tensile strength(kg/mm2)		Phosphor bronze	8.1
ℓ	length of spring with force applied (mm)		inconel	8.25