ASTM A125-96(2013)

Standard Specification for Steel Springs, Helical, Heat-Treated

ABSTRACT
This specification covers the standard for hot-coiled, heat-treated helical compression springs with tapered, closed, squared and ground ends made of hot-wrought round steel bars. Cross sections for hot-wrought round, square, and round-cornered square bars of steel of the bar diameter shall be taken into consideration when designing and calculating the solid height, spring rate, solid stress, and solid capacity. The spring shall undergo quenching and tempering to have sufficiently high hardness and withstand the stresses developed in testing. Springs with specific indentation diameter shall not exceed the specified Brinell hardness numbers. The spring shall meet the metallurgical requirement, end construction, physical requirements such as measurements, solid height, free height, loaded height, permanent set, uniformity of pitch, outside diameter and calculations of solid capacity and uncorrected solid stress.
SCOPE
1.1 This specification covers hot-coiled, heat-treated helical compression springs with tapered, closed, squared and ground ends made of hot-wrought round steel bars 3/8 in. (9.5 mm) and larger in diameter.  
1.2 This specification also serves to inform the user of practical manufacturing limits, mechanical tests, and inspection requirements applicable to the type of spring described in 1.1.  
1.3 Supplementary Requirements S1 to S8 inclusive of an optional nature are provided. They shall apply only when specified by the purchaser. Details of these supplementary requirements shall be agreed upon by the manufacturer and purchaser.  
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

General Information

• Status: Historical
• Publication Date: 30-Sep-2013
• ICS: 21.160 - Springs
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.15 - Bars

Relations

• Replaces: ASTM A125-96(2007) - Standard Specification for Steel Springs, Helical, Heat-Treated
• Effective Date: 01-Oct-2013
• Replaced By: ASTM A125-96(2013)e1 - Standard Specification for Steel Springs, Helical, Heat-Treated
• Effective Date: 01-Oct-2013
• Referred By: ASTM F1370-92(2019)e1 - Standard Specification for Pressure-Reducing Valves for Water Systems, Shipboard
• Effective Date: 01-Oct-2013
• Referred By: ASTM F1508-96(2021) - Standard Specification for Angle Style, Pressure Relief Valves for Steam, Gas, and Liquid Services
• Effective Date: 01-Oct-2013
• Referred By: ASTM D3535-07a(2021) - Standard Test Method for Resistance to Creep Under Static Loading for Structural Wood Laminating Adhesives Used Under Exterior Exposure Conditions
• Effective Date: 01-Oct-2013

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:A125 −96(Reapproved 2013)
Standard Specification for
Steel Springs, Helical, Heat-Treated
This standard is issued under the fixed designation A125; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 3.1.1 Quantity,
3.1.2 Name of material,
1.1 This specification covers hot-coiled, heat-treated helical
3.1.3 A drawing or list showing required dimensions and
compression springs with tapered, closed, squared and ground
loads, and part number,
endsmadeofhot-wroughtroundsteelbars ⁄8 in.(9.5mm)and
3.1.4 Packaging, marking and loading, and
larger in diameter.
3.1.5 End use.
1.2 This specification also serves to inform the user of
practical manufacturing limits, mechanical tests, and inspec-
NOTE 1—A typical ordering description is: 500 springs Drawing 3303
tion requirements applicable to the type of spring described in
Rev. A. to ASTM A125, 1095 steel, for cyclical machine operation.
Palletize, maximum weight 4000 lb.
1.1.
1.3 Supplementary Requirements S1 to S8 inclusive of an
4. Materials and Manufacture
optional nature are provided. They shall apply only when
specified by the purchaser. Details of these supplementary 4.1 Material:
requirements shall be agreed upon by the manufacturer and
4.1.1 Unless otherwise specified, the springs shall be made
purchaser.
of carbon steel bars conforming to the requirements of Speci-
fication A689. Due to hardenability limitations of carbon steel,
1.4 Thevaluesstatedininch-poundunitsaretoberegarded
it is suggested that the bar diameter be limited to 1 ⁄8 in. (41.8
as standard. The values given in parentheses are mathematical
mm) max in order to withstand the maximum test stress
conversions to SI units that are provided for information only
requirements of this specification.
and are not considered standard.
4.1.2 If alloy steel is specified, the springs shall be made
2. Referenced Documents
fromalloysteelbarsconformingtoSpecificationA689.Anyof
the alloy steel grades referred to may be used at the option of
2.1 ASTM Standards:
the spring manufacturer, providing that a minimum as-
A29/A29MSpecification for Steel Bars, Carbon and Alloy,
quenched hardness of Rockwell HRC-50 will be achieved at
Hot-Wrought, General Requirements for
the center of the bar section representing the spring when
A689Specification for Carbon and Alloy Steel Bars for
quenched in the same media and manner as the spring.
Springs
4.1.3 Springs Made from Bars Over 2 in. (50.8 mm)—Note
E10Test Method for Brinell Hardness of Metallic Materials
that the bias tolerance (reference Specification A29/A29M,
E112Test Methods for Determining Average Grain Size
TableA1.1 on Permissible Variations in Cross Section for
E709Guide for Magnetic Particle Testing
Hot-Wrought Round, Square, and Round-Cornered Square
3. Ordering Information
Bars of Steel) of the bar diameter shall be taken into consid-
eration when designing and calculating the solid height, spring
3.1 Orders for springs under this specification shall include
rate, solid stress, and solid capacity.
the following information:
4.2 Hardness:
This specification is under the jurisdiction ofASTM Committee A01 on Steel, 4.2.1 The springs must be quenched and tempered to a
Stainless Steel and RelatedAlloysand is the direct responsibility of Subcommittee
sufficiently high hardness (strength) to withstand the stresses
A01.15 on Bars.
developed in testing the finished spring. The maximum hard-
Current edition approved Oct. 1, 2013. Published November 2013. Originally
ness shall not exceed 477 Brinell numbers (2.80 mm indenta-
approved in 1929. Last previous edition approved in 2007 as A125–96 (2007).
DOI: 10.1520/A0125-96R13. tion diameter).
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4.2.2 When hardness limits are specified, the total range or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
spread may not be less than 0.15 mm difference in indentation
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. diameters. The specified or indicated minimum hardness must
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A125−96 (2013)
TABLE 2 Brinell Hardness
be sufficient to develop the required strength to withstand the
solid stresses of the spring design involved. Indentation Diameter, mm Brinell Hardness Numbers
4.2.3 Hardness shall be read on a prepared flat surface in an 2.75 495
2.80 477
area not detrimental to the life of the spring at a full section
2.85 461
after removal of the decarburized layer. A tungsten-carbide
2.90 444
10-mm ball shall be applied under a 3000-kg load and the 2.95 429
3.00 415
indentation diameter converted to Brinell numbers by using
3.05 401
Table 1. The values for Table 1 have been taken from
3.10 388
Specification E10. 3.15 375
4.3 Metallurgical Requirements:
4.3.1 The total depth of decarburization, partial plus com-
plete as measured on the finished spring in the quenched and
the mean coil circumference and a minimum width of two
tempered condition, shall not exceed 0.006 in. (0.15 mm) plus
thirds of the bar diameter. The tip ends of the bar shall be in
1%ofthebardiameter.Thedecarburizationshallbeexamined
approximate contact with the adjacent coil and shall not
at 100× on a test specimen suitably etched and cut from a full
protrude beyond the maximum permissible outside diameters
cross section of the test spring showing at least one lineal inch
of the spring as established by Table 2.
of original bar circumference.
4.4.2 Springs with ground ends having a free height-to-
4.3.2 The structure of the finished spring shall have an
mean diameter ratio of not less than 1 or more than 5 shall not
averageASTM Grain Size No. 5 or finer as determined by the
deviate from the perpendicular more than the number of
latest revision of Test Methods E112.
degrees prescribed in Table 3, as determined by standing the
spring on its end and measuring the angular deviation of a
4.4 End Construction:
straightedge along the outer helix from a perpendicular to the
4.4.1 EndConstruction-TaperedSquaredandGround—The
plate on which the spring is standing.
end bearing surfaces of the spring shall be ground to produce
4.4.3 Theendsofspringsshallbeparallelwithinatolerance
afirmbearing.Theendbearingsurfacesshallhaveaminimum
oftwicethatspecifiedforthesquarenessofendsasdetermined
bearing surface of two thirds of the mean coil circumference
by standing the spring on its end and measuring the maximum
and a minimum width of two thirds of the hot-tapered surface
angular deviation of the other end from a plane parellel to the
of the bar. The tip ends of the bar shall be in approximate
plate on which the spring is standing.
contact with the adjacent coil, and shall not protrude beyond
the maximum permissible outside diameters of the spring as
5. Physical Requirements
established by Table 2.
4.4.1.1 End Construction Coil Blunt Squared and Ground 5.1 Measurements:
(Optional)—The end bearing surfaces of the spring shall be 5.1.1 Solid Height—The solid height is the perpendicular
distance between the plates of the testing machine when the
ground to produce a firm bearing. The end bearing surfaces
shall have a minimum ground bearing surface of two thirds of spring is compressed solid with the load specified in 7.3. The
TABLE 1 Permissible Out-of-Squareness, Springs with Ground Ends
Total Travel, in. (mm) Mean Diameter, in. (mm)
2 (51) Over 2 Over 4 Over 6 Over 8 Over 10 Over 12 Over 14 Over 16 Over 18
and to 4 to 6 to 8 to 10 to 12 to 14 to 16 to 18 to 20
under (51 to (102 to (152 to (203 to (254 to (305 to (356 to (406 to (457 to
102), incl 152), incl 203), incl 254), incl 305), incl 356), incl 406), incl 457), incl 508), incl
Degree
1 1
2 (51) and under 1 ⁄4 1 ⁄4 1111 . . . .
3 1 1 1
Over 2 to 4 (51 to 102), incl 1 ⁄4 1 ⁄2 1 ⁄4 1 ⁄4 1 1 1 . . .
1 3 1 1 1
Over 4 to 6 (102 to 152), incl 2 ⁄4 1 ⁄4 1 ⁄2 1 ⁄4 1 ⁄4 1 1 . . .
1 1 3 1 1 1
Over 6 to 8 (152 to 203), incl 2 ⁄2 2 ⁄4 1 ⁄4 1 ⁄2 1 ⁄4 1 ⁄4 1 1 . .
3 1 1 1 1 1
Over 8 to 10 (203 to 254), incl 2 ⁄4 2 ⁄2 21 ⁄2 1 ⁄2 1 ⁄4 1 ⁄4 1 . .
3 1 3 1 1 1 1
Over 10 to 12 (254 to 305), incl 3 2 ⁄4 2 ⁄4 1 ⁄4 1 ⁄2 1 ⁄2 1 ⁄4 1 ⁄4 1 .
1 3 3 1 1 1 1
Over 12 to 14 (305 to 356), incl . . . 3 2 ⁄2 21 ⁄4 1 ⁄4 1 ⁄2 1 ⁄2 1 ⁄4 1 ⁄4
3 1 3 3 1 1
Over 14 to 16 (356 to 406), incl . . . . . . 2 ⁄4 2 ⁄4 22 1 ⁄4 1 ⁄4 1 ⁄2 1 ⁄2
1 1 3 3 1
Over 16 to 18 (406 to 457), incl . . . . . . 3 2 ⁄2 2 ⁄4 22 1 ⁄4 1 ⁄4 1 ⁄2
3 1 1 1 3
Over 18 to 20 (457 to 508), incl . . . . . . 3 2 ⁄4 2 ⁄2 2 ⁄4 2 ⁄4 22 1 ⁄4
3 1 1 3
Over 20 to 22 (508 to 559), incl . . . . . . . . . 3 2 ⁄4 2 ⁄4 2 ⁄4 22 1 ⁄4
1 1 3
Over 22 to 24 (559 to 610), incl . . . . . . . . . . . . 3 2 ⁄4 2 ⁄4 22 1 ⁄4
1 1 1 1
Over 24 to 26 (610 to 660), incl . . . . . . . . . . . . . . . 2 ⁄2 2 ⁄2 2 ⁄4 2 ⁄4 2
1 1 1 1
Over 26 to 28 (660 to 701), incl . . . . . . . . . . . . . . . 2 ⁄2 2 ⁄2 2 ⁄4 2 ⁄4 2
3 1 1 1
Over 28 to 30 (702 to 762), incl . . . . . . . . . . . . . . . 2 ⁄4 2 ⁄2 2 ⁄4 2 ⁄4 2
3 3 1 1
Over 30 to 32 (762 to 813), incl . . . . . . . . . . . . . . . 2 ⁄4 2 ⁄4 2 ⁄2 2 ⁄2 .
3 3 1 1
Over 32 to 34 (813 to 864), incl . . . . . . . . . . . . . . . 2 ⁄4 2 ⁄4 2 ⁄2 2 ⁄2 .
3 3 3
Over 34 to 38 (864 to 914), incl . . . . . . . . . . . . . . . 3 2 ⁄4 2 ⁄4 2 ⁄4 .
3 3
Over 36 to 38 (914 to 965), incl . . . . . . . . . . . . . . . . . . 3 2 ⁄4 2 ⁄4 .
Over 38 to 42 (965 to 1016), incl . . . . . . . . . . . . . . . . . . . . . 3 3 . . .
A125−96 (2013)
TABLE 3 Permissible Variations in Outside Diameter of Helix
(For springs with D/d ratio not exceeding 8)
NOTE 1—(for design information) These permissible variations, exclusives of manufacturing taper, should be used as a guide in the design of
concentrically-nested helical-spring units for free assembly. The diametrical clearance desired is ⁄16 in. (1.59 mm) less than the sum of the applicable
tolerances of the nested spring units, but in no case should it be less than ⁄8 in. (3.17 mm).
NOTE 2—In cases where radical clearance on existing concentrically-nested helical-spring units will not accommodate these tolerances, the nominal
insidediametersshallbeadheredtoascloselyaspracticable,withplusvariationontheouterspringsandminusvariationontheinnerspringstoguarantee
free assembly. Drawings must show reference to the complete nested spring units.
NOTE 3—(For springs with D/d ratio not exceeding 8). For D/d ratio greater than 8, increase tolerance 50%.
Nominal Outside Diameter, in. Nominal Free Height or Length of Spring, in. (mm)
(mm)
Up to 10 (254) Over 10 to 18 Over 18 to 26 Over 26 to 34 Over 34 to 42 Over 42 to 60
incl, ± (254 to 457), (457 to 661), (661 to 874), (874 to 1067), (1067 to 1524),
incl, ± incl, ± incl, ± incl, ± incl, ±
1 3 1 5 3
Up to 6 (152), incl ⁄16 (1.59) ⁄32 (2.38) ⁄8 (3.17) ⁄32 (3.97) ⁄16 (4.76) . . .
3 1 3 1 1
Over 6 to 8 (152 to 203), incl ⁄32 (2.38) ⁄8 (3.17) ⁄16 (4.76) ⁄4 (6.35) ⁄4 (6.35) . . .
1 3 1 1 1
Over 8 to 12 (203 to 305), incl ⁄8 (3.17) ⁄16 (4.76) ⁄4 (6.35) ⁄4 (6.35) ⁄4 (6.35) . . .
1 1 1 1 5
Over 12 to 16 (305 to 406), incl . . . ⁄4 (6.35) ⁄4 (6.35) ⁄4 (6.35) ⁄4 (6.35) ⁄16 (7.94)
5 5 5 3
Over 16 to 20 (406 to 508), incl . . . . . . ⁄16 (7.94) ⁄16 (7.94) ⁄16 (7.94) ⁄8 (9.53)
3 3 3 7
Over 20 to 24 (508 to 610), incl . . . . . . ⁄8 (9.53) ⁄8 (9.53) ⁄8 (9.53) ⁄16 (11.00)
7 7 7 1
Over 24 to 28 (610 to 701), incl . . . . . . ⁄16 ⁄16 ⁄16 ⁄2
1 1 1 1
Over 28 (701), incl . . . . . . ⁄2 ⁄2 ⁄2 ⁄2
TABLE 5 Permissible Variations in Free Height, Loaded Height
solid height thus measured may be less, but shall not exceed
and Permanent Set
thespecifiednominalsolidheightbymorethanthelimitsgiven
Nominal Total Deviation Deviation Permanent
in Table 4.
Deflection, in. (mm) From From Set, max,
5.1.2 Free Height—The free height is the height of the
Nominal Free Nominal in. (mm)
Height, max, Loaded
spring after the load specified in 7.3 has been released, and is
A
in.(mm),± Height,
determined by placing a straightedge across the top of the
max,
in.(mm),±
springandmeasuringtheperpendiculardistancefromtheplate
5 4 3
Up to 3 (76.2), incl ⁄32 (3.97) ⁄32 (3.17) ⁄64 (1.19)
on which the spring stands to the bottom of the straightedge at
8 5 4
Over 3 to 4 (76.2 to 102), incl ⁄32 (6.35) ⁄32 (3.97) ⁄64 (1.59)
the approximate center of the spring. Tolerances are shown in
8 6 4
Over 4 to 5 (102 to 127), incl ⁄32 (6.35) ⁄32 (4.76) ⁄64 (1.59)
11 7 5
Table 5.
Over 5 to 6 (127 to 152), incl ⁄32 (8.73) ⁄32 (5.56) ⁄64 (1.99)
11 8 5
Over 6 to 7 (152 to 179), incl ⁄32 (8.73) ⁄32 (6.35) ⁄64 (1.99)
5.1.3 Loaded Height—The loaded height is the perpendicu-
14 9 6
Over 7 to 8 (179 to 203), incl ⁄32 (11.0) ⁄32 (7.14) ⁄64 (2.38)
lardistancebetweentheplatesofthetestingmachinewhenthe
14 10 6
Over 8 to 9 (203 to 228), incl ⁄32 (11.0) ⁄32 (7.94) ⁄64 (2.38)
17 11 7
specified working load has been applied in compression.
Over 9 to 10 (228 to 254), incl ⁄32 (13.49) ⁄32 (8.73) ⁄64 (2.78)
17 12 7
Over 10 to 11 (254 to 279), incl ⁄32 (13.49) ⁄32 (9.53) ⁄64 (2.78)
Tolerances are shown in Table 5.
20 13 8
Over 11 to 12 (279 to 305), incl ⁄32 (15.87) ⁄32 (10.32) ⁄64 (3.17)
5.1.4 Permanent Set—After determining the free height as
20 14 8
Over 12 to 13 (305 to 330), incl ⁄32 (15.87) ⁄32 (11.00) ⁄64 (3.17)
23 15 8
specified in 5.1.2, the permanent set is the difference between Over 13 to 14 (330 to 356), incl ⁄32 (18.25) ⁄32 (11.91) ⁄64 (3.17)
23 16 9
Over 14 to 15 (356 to 381), incl ⁄32 (18.25) ⁄32 (12.70) ⁄64 (3.57)
this free height and the height after the spring has been
26 17 9
Over 15 to 16 (381 to 406), incl ⁄32 (20.64) ⁄32 (13.49) ⁄64 (3.57)
compressed solid three additional times under the test load
26 18 10
Over 16 to 17 (406 to 431), incl ⁄32 (20.64) ⁄32 (14.28) ⁄36 (3.97)
29 19 10
specified in 7.3, measured at the same point and in the same Over 17 to 18 (431 to 457), incl ⁄32 (23.01) ⁄32 (15.08) ⁄64 (3.97)
29 20 11
Over 18 to 19 (457 to 483), incl ⁄32 (23.01) ⁄32 (15.87) ⁄64 (4.37)
manner. Tolerances are shown in Table 5.
21 11
Over 19 to 20 (483 to 508), incl 1 (25.40) ⁄32 (16.67) ⁄64 (4.37)
5.1.5 Uniformity of Pitch—The pitch of the coils shall be
22 12
Over 20 to 21 (508 to 533), incl 1 (25.40) ⁄32 (17.46) ⁄64 (4.76)
3 23 12
sufficiently uniform so that when the spring is compressed Over 21 to 22 (533 to 559), incl 1 ⁄32 (27.78) ⁄32 (18.25) ⁄64 (4.76)
3 24 13
Over 22 to 23 (559 to 584), incl 1 ⁄32 (27.78) ⁄32 (19
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