Bimetal

Specifications

Thermostatic bimetals are today widely used in control ,safety and thermal compensation Systems , due to their reliability, sturdiness and low cost .The wide range of YADA bimetals ,manufactured to DIN standards ASTM standards and chinese GB standards , ensures a Choice of products closely matched to di f ferent speci f ic requi rements. Moreover the tighter gurantees offered by YADA for both the physical properties and dimensional tolerances enable the bimetals to meet the increasingly stringent demands of modern industry.

Working termperature is the temperature is determined by the respective maximum application temperature . Two ranges are to be distinguished,which coincide with the linearity range.

For such a range, bimetal types YDTB1578,YDTB20110 are most suitable. 1578 grades are the most common and the
least expansive bimetals. Although their linear sensitivity range is limited to 200 . They can be used without risk up to 500 , if high sensitivity and linearity are not neccessary. They therefore constitute the basic elements of most safety and control mechanisms, in applications such as automobiles and domestic appliances. If the thermal sensitivity of these grades is not sufficient, YDTB20110 with an almost 40% higher thermal deflection, should be chosen . With this grade , bimetal applications can be extended to cases, where conventional types would not be suitable :small temperature variations, small spaces,etc.For such a range, bimetal types YDTB1578,YDTB20110 areMost suitable. YDTB1578 grades are the most common and theleast expansive bimetals. Although their linear sensitivity range
is limited to 200 . They can be used without risk up to 500 , if high sensitivity and linearity are not neccessary.They therefore constitute the basic elements of most safety and control mechanisms, in applications such as automobiles and domestic appliances.If the thermal sensitivity of these grades is not sufficient, YDTB20110 with an almost 40% higher thermal deflection, should be chosen . With this grade , bimetal applications can be extended to cases, where conventional types would not be suitable :small temperature variations, small spaces,etc.It can also find applications in more simple case, since its high price (due to the nature of the components and the difficuity of manufacture)is partly compensated by the weight savings made possible by its high performance.If, in case of thermal conduction by an external medium, short reacting times are required, bimetals with an intermediate copper layer and higher thermal conductivity such as 1411,11SP can be of advantage.

When higher working temperatures are required, bimetal typesYDTB1070,YDTB1109 are often preferred.YDTB1070 conserves

Electrical resistivity is relevant in those cases where the bimetals carry an electric current, because the change of
temperature that ,ay result from the current is partly determined by this characteristic. Electrical resistivity Very small as well as very high resistivity has to be available. By inserting a nickel or copper layer of appropriate thickness
between the components , the original resistivity of a bimetal can be lowered with the relative ease without considerable loss in thermal deflection. Lines of different resistivities of the above kind are manufactured by YADA with bimetal types 1578;1480:20110(60SP. . .5SP)and wi th1440(1440. . .1303) .Raising the upper limit has been achieved without major loss of thermal deflection with bimetal 14140, which consists of the same commponents as 20110, but with a different ratio of layer thickness.a linear behaviour up to 380 When higher working temperatures Are required, bimetal types YDTB1070,YDTB1109 are often Preferred.YDTB1070 conserves a linear behaviour up to 380 When rapid thermal conduction is required in this range,YDTB1109,a sandwich form of YDTB1070 with a copper layer is
preferred. These bimetals are used in domestic appliances(irons)or in heating equipments.

Unless otherwise stated , the bimetal grade is marked by etching on the active side (HES).The etching consists of the bimetal type and corporate name,and possibly the DIN norm reference,which are repeated in a continious pattern over the entire surface. This marking remains legible even after heat treatment at elevated temperatures. It is possible on request

-to mark the low expansion side
-To mark the other marking.