Значение и использование

If the desired mechanical properties are as described in 4.1.1 for material identified as Classes P-1 through P-7, or in 4.1.2 for material identified as Classes Q-1 through Q-7, the strength level desired can be based on hardness or the equivalent tensile or yield strength as shown in Tables 1-4. If the desired mechanical properties are as set forth in 4.1.3 for material identified as Classes R-1 through R-6, the strength level is based on yield strength as shown in Tables 5 and 6.

The user, after determining the mechanical property requirements of the critical section (that carrying the greatest stress) of the part, should select the composition or compositions from Tables 1-6 that fulfills these requirements and is most suitable for processing.

Область применения

1.1 This practice covers the selection of steel bars according to section and to the mechanical properties desired in the part to be produced. This is not a specification for the procurement of steel. Applicable procurement specifications are listed in Section 5.

1.2 Several steel compositions intended for various sections and mechanical property requirements are presented in Tables 1-6. The criteria for placing a steel composition in one of the three general class designations, Classes P, Q, and R (described in Section 4) are as follows:

1.2.1 Classes P and Q should be capable of developing the mechanical properties shown in Tables 1-4 by liquid quenching from a suitable austenitizing temperature, and tempering at 800°F (427°C) or higher. A hardness indicated by tests made at a location shown in Fig. 1, A, B, or C, is taken as evidence that a composition is capable of meeting other equivalent mechanical properties shown in the tables. Normal good shop practices are assumed, with control of austenitizing and tempering temperatures, and mild agitation of the part in the quenching bath.

1.2.2 Class R should be capable of developing the mechanical properties shown in Tables 5 and 6 as hot rolled, by cold drawing, or by cold drawing with additional thermal treatment. The locations for obtaining tension tests are described in 6.2.

1.3 It is not implied that the compositions listed in the tables are the only ones satisfactory for a certain class and mechanical property requirement. Steels with lower alloy contents are often satisfactory through the use of special processing techniques.

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.

TABLE 1 Steels for Moderately Quenched PartsClasses P-1 Through P-7
(Applicable to oil-quenching or equivalent rate of heat-removal.)

Note 1—Steels listed as approved for a certain section or strength may be used for lighter sections and lower strengths.

Note 2—Steel composition numbers correspond to SAE, AISI, or ASTM designations. Those in italics are no longer considered standard grades due to decreased usage.

Note 3—An H-steel with the same grade designation as a standard SAE-AISI steel is capable of meeting the same section and strength requirements as the standard steel (see Specification A304), and is the preferred method of specification.

Note 4—Steels having a maximum carbon content of 0.40 % or over, or a hardness of HB 293 or over after heat-treating, are not recommended for applications involving welding.

Desired Minimum
Hardness
Equivalent
Tensile
Strength, psi^A
Equivalent
Yield
Strength, psi^A
Minimum^B
As-Quenched
Hardness
Class P-1
P-2
P-3
P-4
P-5
P-6
P-7
Diameter of Round (or Distance Between Faces of Square
or Hexagonal) Sections, in.^C
To ½, incl Over ½ to 1, incl Over 1 to 1¹/₂, incl Over 1½ to 2, inclOver 2 to 2¹/₂, incl Over 2½ to 3, incl Over 3 to 3¹/₂, incl Thickness of Flat Sections, in.^C
HBHRC
HB
HRC
To 0.3, incl
Over 0.3 to 0.6, incl
Over 0.6
to 1,
incl
Over 1
to 1.3,
incl
Over 1.3
to 1.6,
incl
Over 1.6
to 2.0,
incl
Over 2.0
to 2.3,
incl
229 to 293,
incl20 to 33,
incl110 000 to
145 000,
incl90 000 to
125 000,
incl388 421330 4130 50B30
5132 8630 Over 293
to 341,
inclOver 33
to 38,
inclOver 145 000
to 170 000,
inclOver 125 000
to 150 000,
incl 409 441335 94B30 314041374142 9840 4337 31354135 4042 4640 5135 8640 8740 Over 341
to 388,
incl Over 38
to 42,
incl Over 170 000
to 190 000,
inclOver 150 000
to 170 000,
incl455 48134041374140 4145 41474340 31406145TS4140 98404337 4047 8642 86B45 4135 864594B40 5140 8742 8637 TS14B50 50B40 Over 388 to
429, incl Over 42
to 45,
incl Over 190 000
to 205 000,
inclOver 170 000
to 185 000,
incl 496 511345 86455147 41428660 4147 4150E4340 40638740 5155 414598404161 41619850 40688742 516043374340TS4150 41409260 6150 8650 86B45 46409261 9262 8655 5145TS414050B60 515050B46 94B40 51B60 864050B4481B45 864250B50

^A 1 psi = 0.006895 MPa.

^B Minimum as-quenched hardness for obtaining desired hardness after tempering at 800°F (427°C) or higher.

^C 1 in. = 25.4 mm.

TABLE 2 Steels for Drastically Quenched PartsClasses P-1 Through P-7
(Applicable to water-quenching or equivalent rate of heat-removal See Note 5)

Note 1—Steels listed as approved for heavier sections or higher strengths may be used in the same conditions for lighter sections and lower strengths.

Note 2—Steel composition numbers correspond to ASE, AISI, or ASTM designations. Those in italics are no longer considered standard grades due to decreased usage.

Note 3—An H-steel with the same grade designation as a standard SAE-AISI steel is capable of meeting the same section and strength requirements as the standard steel (see Specification A304), and is the preferred method of specification.

Note 4—Steels having a maximum carbon content of 0.40 % or over, or a hardness of HB 293 or over after heat-treating, are not recommended for applications involving welding.

Note 5—Parts made of steel with a carbon content of 0.33 % or higher, where the section is under 1 1/2 in. (38.1 mm) should not be quenched in water without careful exploration for quench-cracking.

Desired Minimum
Hardness
Equivalent
Tensile
Strength, psi^A
Equivalent
Yield
Strength, psi^A
Minimum^B
As-Quenched
Hardness
Class P-1P-2 P-3P-4P-5P-6P-7 Diameter of Round (or Distance Between Faces of Square
or Hexagonal) Sections, in.^C
To ½ , incl
Over ½ to 1, incl
Over 1 to 1¹/₂, incl
Over 1½ to 2, incl
Over 2 to 2¹/₂, incl
Over 2½ to 3, incl
Over 3 to 3¹/₂, incl
Thickness of Flat Sections, in.^C
HB
HRC
HB
HRC
To 0.3, incl
Over 0.3 to 0.6, incl
Over 0.6
to 1.0,
incl
Over 1.0
to 1.3,
incl
Over 1.3
to 1.6,
incl
Over 1.6
to 2.0,
incl
Over 2.0
to 2.3,
incl
229 to 293,
incl20 to 33,
incl110 000 to
145 000,
incl90 000 to
125 000,
incl388 428625413094B30 8627 5130
8630 50B30 Over 293
to 341,
incl Over 33
to 38,
inclOver 145 000
to 170 000,
inclOver 125 000
to 150 000,
incl 409 4440321330 1335 1340^D 3140 4137 40375132 5135 3135^D4135 4337 413094B305140 4640 9840 5130 50B40 8637^D 8630 8640 TS14B35 8740 508B30

^A 1 psi = 0.006895 MPa.

^B Minimum as-quenched hardness for obtaining desired hardness after tempering at 800°F (427°C) or higher.

^C 1 in. = 25.4 mm.

^D These steels have insufficient hardenability for Class P-4, because of difference in test locations, but are satisfactory for other smaller sizes.

TABLE 3 Steels for Moderately Quenched PartsClasses Q-1 Through Q-7
(Applicable to oil-quenching or equivalent rate of heat-removal.)

Note 1—Steels listed as approved for heavier sections or higher strengths may be used in the same conditions for lighter sections and lower strengths.

Note 2—Steel composition numbers correspond to ASE, AISI, or ASTM designations. Those in italics are no longer considered standard grades due to decreased usage.

Note 3—An H-steel with the same grade designation as a standard SAE-AISI steel is capable of meeting the same section and strength requirements as the standard steel (see Specification A304), and is the preferred method of specification.

Note 4—Steels having a maximum carbon content of 0.40 % or over, or a hardness of HB 293 or over after heat-treating, are not recommended for applications involving welding.

Desired Minimum
HardnessEquivalent
Tensile
Strength,
psi^AEquivalent
Yield
Strength,
psi^AMinimum^B
As-
Quenched
Hardness Class Q-1Q-2Q-3Q-4Q-5Q-6Q-7 Diameter of Round (or Distance Between Faces of Square
or Hexagonal) Sections, in.^C To ¹/_2, incl
Over ½
to 1,
incl
Over 1
to 1¹/_2,
incl
Over
1¹/₂
to 2,
incl
Over 2
to 2¹/_2,
incl
Over 2½
to 3,
incl
Over 3
to 3¹/_2,
incl
Thickness of Flat Sections, in.^C HBHRCHBHRC To 0.3, incl
Over 0.3 to 0.6,
incl Over 0.6
to 1.0,
incl Over 1.0
to 1.3,
incl Over 1.3
to 1.6,
incl Over 1.6
to 2.0,
incl Over 2.0
to 2.3,
incl 187 to 293,91 (R_b)95 000 to75 000 to388421330 86308637314041404142 incl to 33, 145 000, 125 000,4130 50B308740TS4140 incl incl incl513294B40 Over 293Over 33OverOver4094413353140 87404137 TS414081B45414241454147 to 341, to 38,145 000125 0004042 50B30413541404337 incl incl to to5135464086429840 170 000,150 000, 94B308640864586B45 incl incl8742 Over 341Over 38OverOver455481340 86371345 87424142 94B4051B60414541474150 to 388, to 42,170 000150 0003135 TS14B504137 TS41405147865543374340 incl incl to to3140 50B404140 50B505155984086B45TS4150 190 000,170 000,404751506150 incl incl41358642 51408645 Over 388Over 42OverOver496511345 864541424145984041474150E4340 to 429, to 45,190 000170 0004047 8740514743374340TS41509850 incl incl to to4063 8742515551608660 205 000,185 000,4068 92606150865086B45 incl incl4140 TS414092618655 4640 50B4694B409262 5145 50B4450B60 5150 50B5051B60 864081B45 8642

^A 1 psi = 0.006895 MPa.

^B Minimum as-quenched hardness for obtaining desired hardness after tempering at 800°F (427°C) or higher.

^C 1 in. = 25.4 mm.

TABLE 4 Steels for Drastically Quenched PartsClasses Q-1 Through Q-7
(Applicable to water-quenching or equivalent rate of heat-removalSee Note 5)

Note 1—Steels listed as approved for heavier sections or higher strengths may be used in the same conditions for lighter sections and lower strengths.

Note 2—Steel composition numbers correspond to SAE, AISI, or ASTM designations. Those in italics are no longer considered standard grades due to decreased usage.

Note 3—An H-steel with the same grade designation as a standard SAE-AISI steel is capable of meeting the same section and strength requirements as the standard steel (see Specification A304), and is the preferred method of specification.

Note 4—Steels having a maximum carbon content of 0.40 % or over, or a hardness of HB 293 or over after heat-treating, are not recommended for applications involving welding.

Note 5—Parts made of steel with a carbon content of 0.33 % or higher, where the section is under 1½ in. (38.1 mm) should not be quenched in water without careful exploration for quench-cracking.

Desired Minimum
HardnessEquivalent
Tensile
Strength,
psi^AEquivalent
Yield
Strength,
psi^AMinimum^B
As-Quenched
HardnessClass Q-1Q-2Q-3Q-4Q-5Q-6Q-7 Diameter of Round (or Distance Between Faces of Square
or Hexagonal) Sections, in.^C To ¹/_2, incl
Over ½
to 1,
inclOver 1
to 1¹/_2,
inclOver 1½
to 2,
inclOver 2
to 2¹/_2,
inclOver 2½
to 3,
inclOver 3
to 3¹/_2,
incl Thickness of Flat Sections, in.^C HBHRCHBHRCTo 0.3, inclOver 0.3
to 0.6, inclOver 0.6
to 1.0,
inclOver 1.0
to 1.3,
inclOver 1.3
to 1.6,
inclOver 1.6
to 2.0,
inclOver 2.0
to 2.3,
incl 187 to 293,91 (HRB)95 000 to75 000 to388421000 series,403751355140^D46403140 incl to 33, 145 000, 125 000, from 1024 to413094B3086378740 incl incl incl 1040, incl^E513050B40^D 86255132 86278630 50B30 Over 293Over 33Over 145 000Over 125 000409441036 to 1045,^E133013351340^D41354137 to 341, to 38, to 170 000, to 150 000, incl50463135^D86404140 incl incl incl incl40325135314087408642 863094B308637^D8645 8742 TS4140 Over 341Over 38Over 170 000Over 150 000455481335313513401345 50B44^D41404142 to 388, to 42, to 190 000, to 170 000,4037 TS14B3540423140413786454337 incl incl incl incl4130404741354640^D5147 5046 50B3051405145^D87426150 513086375150TS41408650 513250B408640^D9840 5135 94B30864281B45 86358740^D94B40 50B50

^A 1 psi = 0.006895 MPa.

^B Minimum as-quenched hardness for obtaining desired hardness after tempering at 800°F (427°C) or higher.

^C 1 in. = 25.4 mm.

^D These steels have insufficient hardenability for Class Q-4 parts because of different location of test specimens, but are satisfactory for smaller sections.

^E For these steels, the yield to tensile-strength ratio will usually be lower than 80 %.

TABLE 5 Steels for Parts Manufactured From Hot Rolled^A and Cold Drawn^B,C BarsClasses R-1 Through R-6

Note 1—Steels listed as approved for heavier section or higher strengths may be used in the same conditions for lighter sections and lower strengths.

Note 2—Steel composition numbers correspond to ASE, AISI, or ASTM designations. Those in italics are no longer considered standard grades due to decreased usage.

Hot-rolled 1000 series steels with a maximum carbon content of 0.40 % only are approved for welding. Only cold-drawn 1000 series steels used in the strength level and section thickness for which hot-rolled steels of the same composition are approved may be welded, and in this case caution should be exercised to see that excessive grain growth does not occur in the heat-affected zone.

Desired Minimum
Yield Strength,
psi^D
Class
R-1R-2 R-3 and R-4 R-5 and R-6 Diameters of Round or Approximately Round Sections, in.^E
To ½ , incl Over ½ to 1, inclOver 1 to 2, incl Over 2 to 3, incl Thickness of Flat Sections, in.^E
To 0.3, incl Over 0.3 to 0.6, incl Over 0.6 to 1.3, inclOver 1.3 to 2.0, incl Over 30 000 to HR 1016 HR 1020 HR 1016 HR 1020HR 1018 HR 1018 35 000, inclHR 1018 HR 1018 HR 1022HR 1019HR 1022 HR 1019HR 1019 HR 1021HR 1030 Over 35 000 toHR 1022HR 1030HR 1030 HR 1035 40 000, inclHR 1030 HR 1035HR 1035 Over 40 000 to HR 1035HR 1040CD 1010 CD 1010 HR 1045 45 000, incl HR 1040 CD 1015 HR 1040 Over 45 000 to CD 1010CD 1010CD 1015 CD 1020 HR 1137 50 000, inclHR 1040 CD 1015HR 1045 CD 1115 HR 1045HR 1045 HR 1137HR 1050 Over 50 000 toCD 1015CD 1020 HR 1137CD 1018 CD 1115CD 1018 HR 1141 55 000, inclHR 1050CD 1115 HR 1141 CD 1020 HR 1050CD 1019 HR 1141 HR 1137HR 1050HR 1141 CD 1025 CD 1025 HR 1144 Over 55 000 toCD 1018 CD 1115 CD 1018 HR 1144CD 1019 CD 1120CD 1022 CD 1120 60 000, inclCD 1025 CD 1019CD 1022CD 1117 CD 1019 HR 1141CD 1025CD 1117 CD 1118 CD 1020 HR 1144

^A Hot-rolled bars are indicated in table by prefix “HR.”

^B Cold-drawn bars are indicated in table by prefix “CD.” These bars are produced by normal practice in cold-drawing and with no stress relief. Bars cold-finished by turning, grinding, turning and polishing, etc., are not covered under cold-drawn bars, as such cold-finished bars have the properties of hot-rolled bars.

^C Classification of cold-drawn steels by size and yield-strength level in this table is based on yield-strength determinations at 0.2 % offset, or as determined by 0.005 in./in. elongation under load for yield strengths up to 90 000 psi, incl, and by 0.006 in./in. elongation under load for yield strengths above 90 000 psi.

^D 1 psi = 0.006895 MPa.

^E 1 in. = 25.4 mm.

TABLE 6 Steels for Parts Produced From Cold-Drawn and Cold-Drawn Stress-Relieved BarsClasses R-1 Through R-6^A,B

Note 1—Steels listed as approved for heavier section or higher strengths may be used in the same conditions for lighter sections and lower strengths.

Note 2—Steel composition numbers correspond to ASE, AISI, or ASTM designations. Those in italics are no longer considered standard grades due to decreased usage.

Note 3—Steels in conditions listed in this table are not approved for applications involving welding.

Desired Minimum
Yield Strength,
psi^C
Class
R-1R-2 R-3 and R-4 R-5 and R-6 Diameters of Round or Approximately Round Sections, in.^D
To ¹/_2, incl Over ½ to 1, inclOver 1 to 2, incl Over 2 to 3, incl Thickness of Flat Sections, in.^D
To 0.3, incl Over 0.3 to 0.6, incl Over 0.6 to 1.3, inclOver 1.3 to 2.0, incl Over 60 000 toCD 1022 CD 1022 CD 1030 CD 1030 65 000, inclCD 1117 CD 1117 CD 1118 CD 1120 CD 1118 CD 1120 Over 65 000 toCD 1030 CD 1030 CD 1035 CD 1035 70 000, inclCDT 1040CD 1035 CDT 1137CD 1050 CD 1118 CDT 1045CDT 1040CDT 1141 CDT 1050CDT 1045 Over 70 000 toCD 1035 CDT 1137CD 1040 CD 1045 75 000, inclCDT 1045CDT 1040CDT 1141CDT 1040 CDT 1050CDT 1045CDT 1144 CDT 1137 CDT 1050 Over 75 000 toCDT 1137CD 1040 CD 1045 CD 1137 80 000, inclCDT 1040CDT 1141CDT 1040CDT 1045 CDT 1050CDT 1045CDT 1144CDT 1040 CDT 1137CDT 1141 CDT 1050CD 1050 Over 80 000 toCD 1040 CD 1045 CD 1137 CD 1141 85 000, inclCDT 1141CDT 1040CDT 1045CDT 1137 CDT 1045CDT 1144CDT 1040CDT 1045 CDT 1137CDT 1141CDT 1040 CDT 1050CD 1050 CDT 1144 CDT 1050 Over 85 000 toCD 1045 CD 1137 CD 1141 CD 1144 90 000, inclCDT 1040CDT 1045CDT 1137CDT 1141 CDT 1144CDT 1040CDT 1145CDT 1137 CDT 1137CDT 1141CDT 1040CDT 1045 CDT 1050CD 1050 CDT 1144CDT 1050 CDT 1050 Over 90 000 toCD 1137 CD 1141 CD 1144 CDT 1144 95 000, inclCDT 1045CDT 1137CDT 1141CDT 1141 CDT 1040CDT 1045CDT 1137CDT 1137 CDT 1141CDT 1050CDT 1045CDT 1050 CD 1050 CDT 1144CDT 1050 CDT 1050 Over 95 000 toCD 1141 CD 1144 CDT 1144CDT 1144 100 000, inclCDT 1137CDT 1141CDT 1141CDT 1141 CDT 1045CDT 1137CDT 1137 CDT 1040CDT 1045CDT 1050 CDT 1144CDT 1050 CDT 1050 Over 100 000 toCD 1144 CDT 1144CDT 1144CDT 1144 105 000, inclCDT 1141CDT 1141CDT 1141 CDT 1137CDT 1137 CDT 1045CDT 1050 CDT 1050 Over 105 000 toCDT 1144CDT 1144CDT 1144 110 000, inclCDT 1141CDT 1141 CDT 1137 CDT 1050 Over 110 000 toCDT 1144CDT 1144 115 000, inclCDT 1141 Over 115 000 toCDT 1144 120 000, incl

^A Conditions and treatments of bars are indicated in this table by the symbols shown below. Bars cold-finished by turning, grinding, turning and polishing, etc., are not covered, as such bars have the properties of hot-rolled bars.

“CD” = Bars produced by normal practice in cold-drawing, and with no stress relief.

“CDT” = Cold-drawn bars with subsequent thermal treatment. Heavier than normal drafts may be required.

^B Classification of cold-drawn steels by size and yield-strength level in this table is based on yield-strength determinations at 0.2 % offset or as determined by 0.005 in./in. elongation under load for yield strengths up to 90 000 psi, and by 0.006 in./in. elongation under load for yield strengths above 90 000 psi.

^C 1 psi = 0.006895 MPa.

^D 1 in. = 25.4 mm.

TABLE 7 Applicable Classes for Critical Section Size

Round, Square, Hexagonal, etc., Sections, Diameter or Dimension Between Opposite Faces, in.^AFlat Sections, Thickness, in.^AApplicable Class Over To and Including Over To and Including . . .½. . .0.3P-1, Q-1, or R-1 ½10.30.6P-2, Q-2, or R-2 11½0.61.0P-3, Q-3, or R-3 1½ 21.01.3P-4, Q-4, or R-4 22½1.31.6P-5, Q-5, or R-5 2½ 31.62.0P-6, Q-6, or R-6 33½2.02.3P-7 or Q-7

^A 1 in. = 25.4 mm.

FIG. 1 Locations in Typical Cross Sections of Steel Bars at Which Desired Properties Are Obtained