1、Designation: A125 96 (Reapproved 2018)Standard Specification forSteel Springs, Helical, Heat-Treated1This standard is issued under the fixed designation A125; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisio
2、n. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This specification covers hot-coiled, heat-t
3、reated helicalcompression springs with tapered, closed, squared and groundends made of hot-wrought round steel bars38 in. (9.5 mm) andlarger in diameter.1.2 This specification also serves to inform the user ofpractical manufacturing limits, mechanical tests, and inspec-tion requirements applicable t
4、o the type of spring described in1.1.1.3 Supplementary Requirements S1 to S8 inclusive of anoptional nature are provided. They shall apply only whenspecified by the purchaser. Details of these supplementaryrequirements shall be agreed upon by the manufacturer andpurchaser.1.4 The values stated in in
5、ch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.5 This international standard was developed in accor-dance with internationally recognized principles on stand
6、ard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A29/A29M Specification for General Requirement
7、s for SteelBars, Carbon and Alloy, Hot-WroughtA689 Specification for Carbon and Alloy Steel Bars forSpringsE10 Test Method for Brinell Hardness of Metallic MaterialsE112 Test Methods for Determining Average Grain SizeE709 Guide for Magnetic Particle Testing3. Ordering Information3.1 Orders for sprin
8、gs under this specification shall includethe following information:3.1.1 Quantity,3.1.2 Name of material,3.1.3 A drawing or list showing required dimensions andloads, and part number,3.1.4 Packaging, marking and loading, and3.1.5 End use.NOTE 1A typical ordering description is: 500 springs Drawing 3
9、303Rev. A. to ASTM A125, 1095 steel, for cyclical machine operation.Palletize, maximum weight 4000 lb.4. Materials and Manufacture4.1 Material:4.1.1 Unless otherwise specified, the springs shall be madeof carbon steel bars conforming to the requirements of Speci-fication A689. Due to hardenability l
10、imitations of carbon steel,it is suggested that the bar diameter be limited to 158 in. (41.8mm) max in order to withstand the maximum test stressrequirements of this specification.4.1.2 If alloy steel is specified, the springs shall be madefrom alloy steel bars conforming to Specification A689.Any o
11、fthe alloy steel grades referred to may be used at the option ofthe spring manufacturer, providing that a minimum as-quenched hardness of Rockwell HRC-50 will be achieved atthe center of the bar section representing the spring whenquenched in the same media and manner as the spring.4.1.3 Springs Mad
12、e from Bars Over 2 in. (50.8 mm)Notethat the bias tolerance (reference Specification A29/A29M,Table A1.1 on Permissible Variations in Cross Section forHot-Wrought Round, Square, and Round-Cornered SquareBars of Steel) of the bar diameter shall be taken into consid-eration when designing and calculat
13、ing the solid height, springrate, solid stress, and solid capacity.4.2 Hardness:4.2.1 The springs must be quenched and tempered to asufficiently high hardness (strength) to withstand the stresses1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related
14、Alloys and is the direct responsibility of SubcommitteeA01.15 on Bars.Current edition approved Sept. 1, 2018. Published September 2018. Originallyapproved in 1929. Last previous edition approved in 2013 as A12596 (2013)1.DOI: 10.1520/A0125-96R18.2For referenced ASTM standards, visit the ASTM website
15、, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesTh
16、is international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (
17、TBT) Committee.1developed in testing the finished spring. The maximum hard-ness shall not exceed 477 Brinell numbers (2.80 mm indenta-tion diameter).4.2.2 When hardness limits are specified, the total range orspread may not be less than 0.15 mm difference in indentationdiameters. The specified or in
18、dicated minimum hardness mustbe sufficient to develop the required strength to withstand thesolid stresses of the spring design involved.4.2.3 Hardness shall be read on a prepared flat surface in anarea not detrimental to the life of the spring at a full sectionafter removal of the decarburized laye
19、r. A tungsten-carbide10-mm ball shall be applied under a 3000-kg load and theindentation diameter converted to Brinell numbers by usingTable 1. The values for Table 1 have been taken from TestMethod E10.4.3 Metallurgical Requirements:4.3.1 The total depth of decarburization, partial plus com-plete a
20、s measured on the finished spring in the quenched andtempered condition, shall not exceed 0.006 in. (0.15 mm) plus1 % of the bar diameter. The decarburization shall be examinedat 100 on a test specimen suitably etched and cut from a fullcross section of the test spring showing at least one lineal in
21、chof original bar circumference.4.3.2 The structure of the finished spring shall have anaverage ASTM Grain Size No. 5 or finer as determined by thelatest revision of Test Methods E112.4.4 End Construction:4.4.1 End Construction-Tapered Squared and GroundTheend bearing surfaces of the spring shall be
22、 ground to producea firm bearing. The end bearing surfaces shall have a minimumbearing surface of two thirds of the mean coil circumferenceand a minimum width of two thirds of the hot-tapered surfaceof the bar. The tip ends of the bar shall be in approximatecontact with the adjacent coil, and shall
23、not protrude beyondthe maximum permissible outside diameters of the spring asestablished by Table 2.4.4.1.1 End Construction Coil Blunt Squared and Ground(Optional)The end bearing surfaces of the spring shall beground to produce a firm bearing. The end bearing surfacesshall have a minimum ground bea
24、ring surface of two thirds ofthe mean coil circumference and a minimum width of twothirds of the bar diameter. The tip ends of the bar shall be inapproximate contact with the adjacent coil and shall notprotrude beyond the maximum permissible outside diametersof the spring as established by Table 2.4
25、.4.2 Springs with ground ends having a free height-to-mean diameter ratio of not less than 1 or more than 5 shall notdeviate from the perpendicular more than the number ofdegrees prescribed in Table 3, as determined by standing thespring on its end and measuring the angular deviation of astraightedg
26、e along the outer helix from a perpendicular to theplate on which the spring is standing.4.4.3 The ends of springs shall be parallel within a toleranceof twice that specified for the squareness of ends as determinedby standing the spring on its end and measuring the maximumangular deviation of the o
27、ther end from a plane parallel to theplate on which the spring is standing.5. Physical Requirements5.1 Measurements:5.1.1 Solid HeightThe solid height is the perpendiculardistance between the plates of the testing machine when thespring is compressed solid with the load specified in 7.3. Thesolid he
28、ight thus measured may be less, but shall not exceedthe specified nominal solid height by more than the limits givenin Table 4.5.1.2 Free HeightThe free height is the height of thespring after the load specified in 7.3 has been released, and isdetermined by placing a straightedge across the top of t
29、hespring and measuring the perpendicular distance from the plateon which the spring stands to the bottom of the straightedge atthe approximate center of the spring. Tolerances are shown inTable 5.5.1.3 Loaded HeightThe loaded height is the perpendicu-lar distance between the plates of the testing ma
30、chine when thespecified working load has been applied in compression.Tolerances are shown in Table 5.5.1.4 Permanent SetAfter determining the free height asspecified in 5.1.2, the permanent set is the difference betweenthis free height and the height after the spring has beencompressed solid three a
31、dditional times under the test loadspecified in 7.3, measured at the same point and in the samemanner. Tolerances are shown in Table 5.5.1.5 Uniformity of PitchThe pitch of the coils shall besufficiently uniform so that when the spring is compressedwithout lateral support to a height representing a
32、deflection of85 % of the nominal total travel, none of the coils shall be incontact with one another, excluding the inactive end coils.Under 85 % deflection, the maximum spacing between any twoadjacent active coils shall not exceed 40 % of the nominal freecoil spacing. The nominal free coil spacing
33、is equivalent to thespecified total travel divided by the number of active turns.When the design is such that it cannot be compressed to solidheight without lateral support, these requirements do not apply.5.1.6 Outside DiameterThe outside diameter shall bemeasured on a spring in the free condition
34、and across any fullturn excluding the end turns and must be taken approximatelyperpendicular to the helix axis. The tolerances are shown inTable 2.5.1.7 Calculations for Testing Loads and Stresses:5.1.7.1 Solid CapacityCalculate the solid capacity of thespring as follows:P 5 Gd4F/8 ND3(1)TABLE 1 Bri
35、nell HardnessIndentation Diameter, mm Brinell Hardness Numbers2.75 4952.80 4772.85 4612.90 4442.95 4293.00 4153.05 4013.10 3883.15 375A125 96 (2018)2where:G = 11106psi = effective torsional modulus of elasticity,d = nominal bar diameter, in.,D = mean coil or helix diameter, in.,F = spring deflection
36、 = free to solid, in.,N = active turns = (solid height)/bar diameter) 1.5, andP = solid capacity, lb.5.1.7.2 Uncorrected Solid StressCalculate the uncorrectedsolid stress as follows: (WarningBar nominal diameter maynot be the same as the specified diameter, due to biasedtolerances on hot-rolled bars
37、 2 in. (50.8 mm) and over.)S 5 8PD/3.1416 d3(2)TABLE 2 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 ofconcentrica
38、lly-nested helical-spring units for free assembly. The diametrical clearance desired is116 in. (1.59 mm) less than the sum of the applicabletolerances of the nested spring units, but in no case should it be less than18 in. (3.17 mm).NOTE 2In cases where radical clearance on existing concentrically-n
39、ested helical-spring units will not accommodate these tolerances, the nominalinside diameters shall be adhered to as closely as practicable, with plus variation on the outer springs and minus variation on the inner springs to guaranteefree assembly. Drawings must show reference to the complete neste
40、d 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.(mm)Nominal Free Height or Length of Spring, in. (mm)Up to 10 (254)incl, Over 10 to 18(254 to 457),incl, Over 18 to 26(457 to 661),incl, Over 26 to 34
41、(661 to 874),incl, Over 34 to 42(874 to 1067),incl, Over 42 to 60(1067 to 1524),incl, Up to 6 (152), incl116 (1.59)332 (2.38)18 (3.17)532 (3.97)316 (4.76) . . .Over 6 to 8 (152 to 203), incl332 (2.38)18 (3.17)316 (4.76)14 (6.35)14 (6.35) . . .Over 8 to 12 (203 to 305), incl18 (3.17)316 (4.76)14 (6.3
42、5)14 (6.35)14 (6.35) . . .Over 12 to 16 (305 to 406), incl . . .14 (6.35)14 (6.35)14 (6.35)14 (6.35)516 (7.94)Over 16 to 20 (406 to 508), incl . . . . . .516 (7.94)516 (7.94)516 (7.94)38 (9.53)Over 20 to 24 (508 to 610), incl . . . . . .38 (9.53)38 (9.53)38 (9.53)716 (11.00)Over 24 to 28 (610 to 701
43、), incl . . . . . .71671671612Over 28 (701), incl . . . . . .12121212TABLE 3 Permissible Out-of-Squareness, Springs with Ground EndsTotal Travel, in. (mm) Mean Diameter, in. (mm)2 (51)andunderOver 2to 4(51 to102), inclOver 4to 6(102 to152), inclOver 6to 8(152 to203), inclOver 8to 10(203 to254), incl
44、Over 10to 12(254 to305), inclOver 12to 14(305 to356), inclOver 14to 16(356 to406), inclOver 16to 18(406 to457), inclOver 18to 20(457 to508), inclDegree2 (51) and under 114 114 1111. . . .Over 2 to 4 (51 to 102), incl 134 112 114 114 1 1 1 . . .Over 4 to 6 (102 to 152), incl 214 134 112 114 114 1 1 .
45、 . .Over 6 to 8 (152 to 203), incl 212 214 134 112 114 114 1 1 . .Over 8 to 10 (203 to 254), incl 234 212 2112 112 114 114 1 . .Over 10 to 12 (254 to 305), incl 3 234 214 134 112 112 114 114 1 .Over 12 to 14 (305 to 356), incl . . . 3 212 2134 134 112 112 114 114Over 14 to 16 (356 to 406), incl . .
46、. . . . 234 214 2234 134 112 112Over 16 to 18 (406 to 457), incl . . . . . . 3 212 214 2234 134 112Over 18 to 20 (457 to 508), incl . . . . . . 3 234 212 214 214 2234Over 20 to 22 (508 to 559), incl . . . . . . . . . 3 234 214 214 134Over 22 to 24 (559 to 610), incl . . . . . . . . . . . . 3 214 214
47、 2234Over 24 to 26 (610 to 660), incl . . . . . . . . . . . . . . . 212 212 214 214 2Over 26 to 28 (660 to 701), incl . . . . . . . . . . . . . . . 212 212 214 214 2Over 28 to 30 (702 to 762), incl . . . . . . . . . . . . . . . 234 212 214 214 2Over 30 to 32 (762 to 813), incl . . . . . . . . . . .
48、. . . . 234 234 212 212 .Over 32 to 34 (813 to 864), incl . . . . . . . . . . . . . . . 234 234 212 212 .Over 34 to 38 (864 to 914), incl . . . . . . . . . . . . . . . 3 234 234 234 .Over 36 to 38 (914 to 965), incl . . . . . . . . . . . . . . . . . . 3 234 234 .Over 38 to 42 (965 to 1016), incl . .
49、 . . . . . . . . . . . . . . . . . . . 3 3 . . .TABLE 4 Permissible Variations in Solid HeightNominal Solid Height, in. (mm) Deviation Above Nominal SolidHeight, max, in.A(mm)Up to 7 (178), incl116 (1.59)Over 7 to 10 (178 to 254), incl332 (2.38)Over 10 to 13 (254 to 330), incl18 (3.17)Over 13 to 16 (330 to 406), incl532 (3.97)Over 16 to 19 (406 to 483), incl316 (4.76)Over 19 to 22 (483 to 559), incl732 (5.56)Over 22 to 25 (559 t
