Overview

• Space can be efficiently used and the initial length of the spring can be effectively used. Extension spring is commonly used like compression spring and has various hook shape according to the application

Application

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

Shape

• It has hooks at the both ends.

Manufacturing capability

• We manufacture extension springs with a diameter of Ø 0.2mm to Ø 6mm.

Others

• Plating, coloring, power coating etc available

Symbols used for extension spring design

Item	Symbol
shear modulus	G
wire diameter	d
outside diameter	Do
mean coil diameter	Dm
inside diameter	Di
total number of coils	Nt
number of active coils	Ne
free length	L
tensile strength
mounting length	I
initial load	Po
initial stress
Load	P
spring constant	K
index ratio	C
stress correction coefficient	K'
shear stress