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Bimetal Material- Product Brief

The Definition and Operating Principle of Bimetals:
Bimetal is bonding by two or more different expansion coefficients metal or alloy, whose shape changes at changing temperature.
1、The active side of the bimetal requests large expansion coefficients, high melting point and similar modulus of elasticity with the passive side. And, there are many choices for the raw material of the active side, such as resisto, nickel-ironmanganese,manganin, pure Nickel, pure iron, brass, bronze,stainless steel, etc. Commonly used are Mn72Cu18Ni10,Ni22Cr3, Ni20Mn6, Ni18Cr11, Ni19Cr2, Ni25Cr8, etc.
2、The passive side of the bimetal usually is the ferro-nickel with low expansion coefficients.In 1896, Guillaume invented the invar which having low expansion coefficients, at the room temperature only about 1.2×10-6/℃. It built up the foundation for the bimetal development. Commonly used are Ni36Fe, Ni39Fe, Ni40Fe,Ni42Fe, Ni45Fe and Ni50Fe.
3、In order to attain different resistivity among the bimetal, we usually put in the lower resistivity metal between the active and passive side to affect the resistivity, such as pure Nickel, pure Copper, Zirconium- Copper, etc.

Instructions for use:

1. Following factors should be considered in designing a bimetal element:
a. Current level for element to stand
b. Operating temperature;
c. Maximum temperature for element to stand ;
d. The requirements of the displacement and power;
e. Space constraint;
f. Working condition, etc .
2. Bimetal Types and Specifications
a. Classified by using temperature: low temperature,medium temperature, high temperature.
b. Bimetal type, size and shape are dependent on the value calculated by motion space, displacement, current level and release force High-sensitive type,Medium-sensitive type,Low-sensitive type.
c. In line with the calculated outcome to make the installation test.
1) The temperature range of application is a little larger than the linear temperature range. Within this range,bimetal with free deformation will not present the residual
deformation.While beyond that range, the bimetal material’s expansion coefficient will have a great change so that the sensitive of the bimetal will be decreased. But it still can
be used.And this temperature is generally lower than the Curie point, of the material, since the material structure and performance will change once reached the Curie point.
2) According the motion space,displacement, current level, tripping force, and etc, to figure out the bimetal type, dimension and shape.High-sensitive Low-resistance(Big ampere) StripShape Medium-sensitive Medium-resistance(Mediumampere) Spirality Low- sensitive High- resistance ( Small-ampere)Isomerism

Product specifications:

1. Classified by Temperature
1)High Temperature
If FPA223-70、FPA206-70、FPA258-70、FPA206-9 etc.
2)Medium Temperature If FPA223-80、FPA206-78 etc.
3)Low Temperature
If FPA721-110、FPA721-140 etc. 
2. Classified by Heat Reactive:
1)High-sensitive ( Flexivity > 30×10-6 /℃): FPA721 series
2)Medium- sensitive ( Flexivity is at the range of 15~30×10-6/℃):
FPA 206 series, FPA 223 series, etc.
 3)Low- sensitive ( Flexivity <15×10 -6/℃): FPA982-2,FPA258-60,etc.
3. Classified by Resistance:
1)Low -Resistance series: FPA721-5, FPA982-2, FPA206-3,
FPA982-4 etc.
2)Medium- Resistance series: FPA223-25, FPA223-35, FPA721-
20, FPA721-40 etc.
3)High- Resistance series: FPA721-140, FPA721-110, FPA23-93, FPA223-110 etc.
●Thickness:0.05- 3.0mm
●Width:1 - 150mm
●Inradium:300mm, 350mm, 400mm
●Thickness tolerance

The main technical indicators: