ASTM B388-00

Standard Specification for Thermostat Metal Sheet and Strip

SCOPE
1.1 This specification covers thermostat metals in the form of sheet or strip that are used for the temperature-sensitive elements of devices for controlling, compensating, or indicating temperature and is intended to supply acceptance requirements to purchasers ordering this material by type designation.
1.2 The values in inch-pound units are to be regarded as the standard. The metric equivalent to inch-pound units may be approximate.

General Information

• Status: Historical
• Publication Date: 09-Oct-2000
• ICS: 77.150.99 - Other products of non-ferrous metals
• Technical Committee: B02 - Nonferrous Metals and Alloys
• Drafting Committee: B02.10 - Thermostat Metals and Electrical Resistance Heating Materials

Relations

• Replaced By: ASTM B388-06 - Standard Specification for Thermostat Metal Sheet and Strip
• Effective Date: 01-Jun-2006
• Referred By: ASTM B753-07(2018) - Standard Specification for Thermostat Component Alloys
• Effective Date: 10-Oct-2000
• Referred By: ASTM B223-08(2018) - Standard Test Method for Modulus of Elasticity of Thermostat Metals (Cantilever Beam Method)
• Effective Date: 10-Oct-2000

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: B 388 – 00
Standard Specification for
Thermostat Metal Sheet and Strip
This standard is issued under the fixed designation B 388; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Ordering Information
1.1 This specification covers thermostat metals in the form 4.1 Orders for material under this specification shall include
of sheet or strip that are used for the temperature-sensitive the following information:
elements of devices for controlling, compensating, or indicat- 4.1.1 Type designation (Table 1 and Table 2),
ing temperature and is intended to supply acceptance require- 4.1.2 Thickness (see 9.1),
ments to purchasers ordering this material by type designation. 4.1.3 Width (see 9.2),
1.2 The values in inch-pound units are to be regarded as the 4.1.4 Temper (designated as percent cold reduction as
standard. The metric equivalent to inch-pound units may be needed),
approximate. 4.1.5 Marking to identify vendor, type, high-expansion side
or low-expansion side,
2. Referenced Documents
4.1.6 Weight.
2.1 ASTM Standards:
5. Material Segregation
B 63 Test Method for Resistivity of Metallically Conduct-
ing Resistance and Contact Materials 5.1 The thermostat metal shall be supplied segregated into
B 106 Test Method for Flexivity of Thermostat Metals two groups after slitting: (1) the burr on the low-expansive
B 223 Test Method for Modulus of Elasticity of Thermostat component, and (2) the burr on the high-expansive component.
Metals (Cantilever Beam Method) These two groups shall be identified and packaged separately
B 362 Mechanical Troque Rate of Spiral Coils of Thermo- or together as mutually agreed upon between the producer and
stat Metals the user.
B 389 Thermal Deflection Rate of Spiral and Helical Coils
6. Chemical Composition
of Thermostat Metals
B 478 Test Method for Cross Curvature of Thermostat 6.1 The nominal composition of component materials is
given in Table 1.
Metals
B 753 Specification for Thermostat Component Alloys 6.1.1 The component alloys shall be as specified in Speci-
fication B 753.
C 351 Test Method for Mean Specific Heat of Thermal
Insulation
7. Component Ratio
E 92 Test Method for Vickers Hardness of Metallic Mate-
7.1 Thetypicalthicknessratioofthecomponentmaterialsis
rials
given in Table 1. The component thickness ratios are given for
E 384 Test Method for Microhardness of Materials
reference as they are lot-to-lot variable to produce required
3. Terminology
flexivity and resistivity.
3.1 Definition:
8. Physical Requirements
3.1.1 thermostat metal—a composite material comprising
8.1 Maximum Sensitivity Range—The temperature ranges
two or more metallic layers of differing coefficients of thermal
of maximum thermal response of designated types of thermo-
expansion such that the radius of curvature of the composite
stat metals are given in Table 2 and Table 3. These are nominal
changes with temperature change.
values presented only to aid users in designing devices.
8.2 Maximum Recommended Temperature— The maximum
This test method is under the jurisdiction of ASTM Committee B02 on
recommended temperatures of use of designated types of
Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee
thermostat metals are given in Table 2 and Table 3. These
B02.10 on Thermostat Metals.
Current edition approved Oct. 10, 2000. Published November 2000. Originally values are presented to aid users in designing devices.
published as B 388 – 62 T. Last previous edition B 388 – 96.
8.3 Flexivity—The flexivity of a designated thermostat
Annual Book of ASTM Standards, Vol 03.04.
metal shall conform to the values in Table 2a and Table 3b.
Annual Book of ASTM Standards, Vol 04.06.
Component materials designated in Specification B 753 shall,
Annual Book of ASTM Standards, Vol 03.01.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
B 388
in thermostat metal combinations, yield product in conform-
ance with the values designated in Table 2a and Table 3b.
TABLE 1 Composition
ASTM Type
Element
TM1 TM2 TM3 TM4 TM5 TM6 TM7 TM8
Nominal chemical high-expansive nickel 22 10 25 25 25 22 14 10
composition, component chromium 3 . 8.5 8.5 8.5 3 . .
weight,% manganese . 72 . . . . 9.5 72
copper . 18 . . . . . 18
iron 75 . 66.5 66.5 66.5 75 71.5 .
aluminum . . . . . . 5 .
carbon . . . . . . . .
intermediate nickel . . . . . . . .
component manganese . . . . . . . .
low-expansive nickel 36 36 42 45 50 40 36 36
component iron 64 64 58 55 50 60 64 64
cobalt . . . . . . . .
Component ratio, high-expansive 50 53 50 50 50 50 50 80
thickness, % component
intermediate . . . . . . . .
component
low-expansive 50 47 50 50 50 50 50 20
component
ASTM Type
Element
TM9 TM10 TM11 TM12 TM13 TM14 TM15 TM16
Nominal chemical high-expansive nickel 22 22 22 22 22 22 22 22
composition, component chromium 3 3 3 3 3 3 3 3
weight,% manganese . . . . . . . .
copper . . . . . . . .
iron 7575 7575 757575 75
aluminum . . . . . . . .
carbon . . . . . . . .
intermediate nickel 100 100 100 100 100 100 100 100
component manganese . . . . . . . .
low-expansive nickel 36 36 36 36 36 36 36 36
component iron 64 64 64 64 64 64 64 64
cobalt . . . . . . . .
Component ratio, high-expansive 27 34 36 40 42 44 47 48
thickness, % component
intermediate 46 32 28 20 16 12 6 4
component
low-expansive 27 34 36 40 42 44 47 48
component
ASTM Type
Element
TM17 TM18 TM19 TM20 TM21 TM22 TM23
Nominal chemical high-expansive nickel 22 19.4 19.4 18 18 100 10
composition, component chromium 3 2.25 2.25 11.5 11.5 . .
weight,% manganese . . . . . . 72
copper . . . . . . 18
iron 75 78.3 78.3 70.5 70.5 . .
aluminum . . . . . . .
carbon . 0.5 0.5 . . . .
intermediate nickel 100 . . . . . .
component manganese . . . . . . .
low-expansive nickel 36 42 39 36 42 36 42
component iron 64 58 61 64 58 64 58
cobalt . . . . . . .
Component ratio, high-expansive 49 50 50 50 50 50 54
thickness,% component
intermediate 2 . . . . . .
component
low-expansive 49 50 50 50 50 50 46
component
B 388
TABLE 1 Continued
ASTM Type
Element TM24 TM25 TM26 TM27 TM28 TM29 TM30
Nominal chemical high-expansive nickel 22 22 22 22 22 20 22
composition, component chromium 3 3 3 3 3 . 3
weight, % manganese . . . . . 6.5 .
copper . . . . . . .
iron 75 75 75 75 75 73.5 75
aluminum . . . . . . .
carbon . . . . . . .
intermediate copper 100 100 100 100 100 . .
component manganese . . . . . . .
low-expansive nickel 36 36 36 36 36 36 42
component iron 64 64 64 64 64 64 58
cobalt . . . . . . .
ASTM Type
Element
TM24 TM25 TM26 TM27 TM28 TM29 TM30
resistivity ohm cir 20 30 50 70 90 477 415
mil/ft
Component ratio, high-expansive 10 20 31 38 42 50 50
thickness, % component
intermediate 53 35 20 14 10 . .
component
low-expansive 37 45 49 48 48 50 50
component
8.3.1 The flexivity shall be determined by Test Method upon between the producer and the user. In the case of three or
B 106, Method A. more components, the hardness of the outer components only
are determined.
8.3.2 Residual stress loading can affect flexivity test results.
Specimensshallbestabilizedpriortotestingbystressrelieffor 8.8.1 The hardness shall be determined by Test Method
1 h at 500°F (260°C). Suitable stress relief conditions must be E 92, when test loads of 1 kgf (9.8 N) or higher are used. For
determined for individual end use applications. Initial condi- thinner materials requiring the use of test loads between 1 kgf,
tion recommendations are given in Table Table 2. hardness shall be determined by Test Method E 384.
8.4 Electrical Resistivity—The electrical resistivity shall 8.8.1.1 WhenusingTestMethodE 384,thepreferredunitof
conform to the values given in Table 2a and Table 3b. measurement shall be Vickers hardness (HV) as defined in 3.3
Component materials designated in Specification B 753 shall, of that method.
in thermostat metal combinations, yield product in conform-
8.8.1.2 When testing thermostat metals, the thickness of an
ance with the values designated in Table 2a and Table 3b.
individual component shall be at least one and one-half times
8.4.1 The electrical resistivity shall be determined by the diagonal length of the hardness indenter impression.
Method B 63 at 75°F (24°C).
8.8.1.3 The center of the impression shall not be closer to
8.5 Modulus of Elasticity—Thenominalmoduliofelasticity any edge of test specimen or to another impression than a
of designated thermostat metals at a temperature of 75°F distance equal to two and one-half times the length of diagonal
(24°C) are given in Table 2a and Table 3b. These are nominal of the impression. When laminated material is tested, a bond
values presented to aid users in designing devices and shall not interface shall be considered as an edge for spacing of
be used for rejection or acceptance purposes. indentation calculations.
8.5.1 The modulus of elasticity shall be determined by Test
9. Dimensions and Permissible Variations
Method B 223.
8.6 Specific Heat—The nominal specific heat of the desig-
9.1 Thickness—The thickness shall be that specified in the
nated thermostat metals is 0.12 BTU/lb°F (500 J/kg°K). This
purchase order or drawing and the tolerance shall be as
nominal value is presented to aid users in designing devices
specified in Table 4.
and shall not be used for rejection or acceptance purposes.
9.2 Width—The width shall be that specified in the purchase
8.6.1 The specific heat shall be determined by Test Method
order or drawing and the tolerance shall be as specified in
C 351.
Tables 5 and 6.
8.7 Density—The nominal densities of designated thermo-
9.3 Coils—Material furnished in the form of coils shall be
stat metals are given in Table 2a and Table 3b. These are
suppliedasmutuallyagreeduponbetweentheproducerandthe
nominal values presented to aid users in designing devices and
user. The inner diameter and the outer diameter or the inner
shall not be used for rejection or acceptance purposes.
diameter and the maximum or minimum weight may be
8.8 Hardness—The hardness of the components of a desig- specified. As mutually agreed upon between the producer and
nated thermostat metal shall conform to those specifications the user a specified maximum percentage may be supplied less
established by the producer and shall be as mutually agreed than the minimum outer diameter or weight specified.
B 388
TABLE 2 Properties of Thermostat Metals (Inch-Pound Units)
ASTM Type
Properties Units
TM1 TM2 TM3 TM4 TM5 TM6 TM7 TM8
Maximum sensitivity °F 0 to 300 0 to 400 200 to 600 250 to 700 300 to 850 100 to 550 0 to 300 0 to 400
temperature range
Maximum recommended °F 1000 500 1000 1000 1000 1000 900 500
temperature
−6
Flexivity 3 10 50 to 200°F 15.0 6 5 % 21.5 6 5 % 10.4 6 6% 8.4 6 6% 6.3 6 6 % 12.96 8 % 14.5 6 7 % 15.9 6 8%
100 to 300°F 14.6 6 5 % 21.1 6 5 % 10.6 6 6% 8.6 6 6% 6.4 6 6 % 12.9 6 8 % 14.56 7 % 15.9 6 8%
Heat treatment °F 700 500 700 700 700 700 700 500
Electrical resistivity at V·cmil/ft 475 6 4% 675 6 5% 440 6 4% 400 6 4% 350 6 5% 440 6 4% 560 6 4% 850 6 5%
75°F V·mil /ft 3736 4% 5306 5% 3466 4% 3146 4% 2756 5% 3466 4% 4406 4% 6686 5%
Modulus of elasticity psi 3 10 25 20 25 25 25.5 25 24 19.5
Density lb/in. 0.29 0.28 0.29 0.29 0.29 0.29 0.28 0.27
TM9 TM10 TM11 TM12 TM13 TM14 TM15 TM16
Maximum sensitivity °F 0 to 300 0 to 300 0 to 300 0 to 300 0 to 300 0 to 300 0 to 300 0 to 300
temperature range
Maximum recommended °F 900 900 900 900 900 900 900 900
temperature
−6
Flexivity 3 10 50 to 200°F 11.5 6 10 % 13.1 6 6% 13.7 6 6% 14.1 6 5.5 % 14.46 5.5 % 14.7 6 5.5 % 14.86 5.5 % 15.0 6 5.5 %
100 to 300°F 11.26 10 % 12.76 6% 13.3 6 6% 13.76 5.5 % 14.0 6 5.5 % 14.36 5.5 % 14.46 5.5 % 14.56 5.5 %
Heat treatment °F 700 700 700 700 700 700 700 700
Electrical resistivity at V·cmil/ft 100 6 5.5 % 125 6 5.5 % 1506 5.5 % 175 6 5.5 % 2006 5.5 % 250 6 5.5 % 3006 5.5 % 350 6 5.5 %
75°F V·mil /ft 786 5.5 % 986 5.5 % 118 6 5.5 % 1376 5.5 % 157 6 5.5 % 196 6 5.5 % 2366 5.5 % 2756 5.5 %
Modulus of elasticity psi 3 10 26 26 26 25.5 25.5 25.5 25 25
Density lb/in. 0.31 0.30 0.30 0.30 0.30 0.30 0.30 0.29
TM17 TM18 TM19 TM20 TM21 TM22 TM23
Maximum sensitivity °F 0 to 300 200 to 600 150 to 450 0 to 300 200 to 600 0 to 300 200 to 600
temperature range
Maximum recommended °F 900 900 900 900 900 900 500
temperature
−6
Flexivity 3 10 50 to 200°F 15.0 6 5.5 % 12.06 7% 14.3 6 7% 13.9 6 5% 11.3 6 7% 10.2 6 5% 18.5 6 5%
100 to 300°F 14.66 5.5 % 12.06 7% 14.16 7% 13.96 5% 11.3 6 7% 10.2 6 5% 18.56 5%
Heat treatment °F 700 700 700 700 700 700 500
Electrical resistivity at V·cmil/ft 400 6 5.5 % 420 6 4% 456 6 5% 472 6 4% 430 6 4% 92 6 6% 565 6 4%
75°F V·mil /ft 3146 5.5 % 3306 4% 3586 5% 3716 4% 3386 4% 726 6% 4446 4%
Modulus of elasticity psi 3 10 25 25 25 25 25 26 20
Density lb/in. 0.29 0.29 0.29 0.29 0.29 0.31 0.28
TM24 TM25 TM26 TM27 TM28 TM29 TM30
Maximum sensitivity °F 0 to 300 0 to 300 0 to 300 0 to 300 0 to 300 0 to 300 200 to 600
temperature range
Maximum recommended °F 500 500 500 500 500 1000 1000
temperature
−6
Flexivity 3 10 50 to 200°F 12.8 6 5% 13.9 6 5% 14.6 6 4% 14.7 6 4% 14.8 6 4% 15.8 6 6% 11.8 6 6%
100 to 300°F 12.66 5% 13.56 5% 14.3 6 4% 14. 56 4% 14.6 6 4% 15.6 6 6% 12.26 6%
Heat treatment °F 500 500 500 500 500 700 700
Electrical resistivity at V·cmil/ft 206 10 % 30 6 7.5 % 506 7.5 % 70 6 7.5 % 90 6 5% 477 6 4 415 6 4
75°F V·mil /ft 15.76 10 % 23.66 7.5 % 39.3 6 7.5 % 556 7.5 % 70.6 6 5% 375 6 4 326 6 4
Modulus of elasticity psi 3 10 24 24 23 23 22 25 25
Density lb/in. 0.29 0.29 0.29 0.29 0.29 0.29 0.29
9.3.1 Welds—Welds used to provide single continuous height. The cross curvature tolerance shall be as mutually
lengths necessary to meet coil size or weight specifications
agreed to between the producer and the user.
shall be clearly identified as established by the producer or as
9.5.1 The cross curvature shall be determined by Test
mutually agreed upon between the producer and the user. The
Method B 478.
welds shall be to the material dimensions or smaller. A
9.6 Flatness—The maximum
...