ASTM A27 - A 27M - 20

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Designation: A27/A27M −20
Standard Speciﬁcation for
Steel Castings, Carbon, for General Application
1
This standard is issued under the ﬁxed designation A27/A27M; 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 (´) 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. Scope*
1.1 This speciﬁcation covers carbon steel castings for gen-
eral applications that require up to 70 ksi (485 MPa) minimum
tensile strength.
NOTE 1—The grades covered by this speciﬁcation represent materials
that are suitable for assembly with other steel castings or wrought steel
parts by fusion welding. It is not intended to imply that all these grades
possess the same degree of weldability or that the same welding
techniques can be used on all castings. It is the responsibility of the
purchaser to establish for himself a suitable welding technique.
1.2 Several grades and two classes of steel castings are
covered, as indicated below. The grade and class desired shall
be speciﬁed by the purchaser.
1.2.1 Grade N-1—Chemical analysis only.
1.2.2 Grade N-2—Heat treated but not mechanically tested.
1.2.3 Grade U-60-30 [415-205]—Mechanically tested but
not heat treated.
1.2.4 Grades 60-30 [415-205], 65-35 [450-240], 70-36
[485-250], and 70-40 [485-275]—Heat treated and mechani-
cally tested.
1.2.5 Class 1 and Class 2 steel castings shall be speciﬁed in
accordance with 9.2.
1.3 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. The values stated in
each system may not be exact equivalents; therefore, each
system shall be used independently of the other. Combining
values from the two systems may result in nonconformance
with the standard.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
2
A781/A781M Speciﬁcation for Castings, Steel and Alloy,
Common Requirements, for General Industrial Use
A957/A957M Speciﬁcation for Investment Castings, Steel
and Alloy, Common Requirements, for General Industrial
Use
3. General Conditions for Delivery
3.1 Except for steel investment castings, material furnished
to this speciﬁcation shall conform to the requirements of
Speciﬁcation A781/A781M, including any supplementary re-
quirements that are indicated in the purchase order. Failure to
comply with the general requirements of Speciﬁcation A781/
A781M constitutes nonconformance with the speciﬁcation. In
case of a conﬂict between the requirements of this speciﬁcation
and Speciﬁcation A781/A781M, this speciﬁcation shall pre-
vail.
3.2 Steel investment castings furnished to this speciﬁcation
shall conform to the requirements of Speciﬁcation A957/
A957M, including any supplementary requirements that are
indicated in the purchase order. Failure to comply with the
common requirements of Speciﬁcation A957/A957M consti-
tutes nonconformance with this speciﬁcation. In case of con-
ﬂict between the requirements of this speciﬁcation and Speci-
ﬁcation A957/A957M, Speciﬁcation A957/A957M shall
prevail.
4. Ordering Information
4.1 Orders for material under this speciﬁcation should
include the following information in proper sequence.
4.1.1 Quantity,
1
This speciﬁcation is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
A01.18 on Castings.
Current edition approved May 1, 2020. Published May 2020. Originally
approved in 1901. Last previous edition approved in 2019 as A27/A27M – 19. DOI:
10.1520/A0027_A0027M-20.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

4.1.2 Speciﬁcation, grade (1.2), and class (9.2),

4.1.3 Description of the casting by pattern number or

drawing,

4.1.4 Options in the speciﬁcation, and

4.1.5 Supplementary requirements desired, including stan-

dards of acceptance.

5. Heat Treatment

5.1 All castings of Grades N-2, 60-30 [415-205], 65-35

[450-240], 70-36 [485-250], and 70-40 [485-275] shall be heat

treated by annealing, normalizing, normalizing and tempering,

or quenching and tempering. Unless otherwise speciﬁed in the

inquiry, contract, or order, the castings may be heat treated by

any one or combination of these heat treatments at the option

of the manufacturer.

5.1.1 Heat treatment shall be performed after castings have

been allowed to cool from the pouring temperature to below

the transformation range.

5.2 Furnace temperatures for heat treating shall be regulated

by the use of pyrometers.

6. Chemical Composition

6.1 The steel shall conform to the requirements as to

chemical composition prescribed in Table 1. Product analysis

tolerances shall conform to the Product Analysis Tolerances

shown in Speciﬁcation A781/A781M or Speciﬁcation A957/

A957M. When residual element chemical content is of interest

to the purchaser, S54 may be considered.

7. Tensile Properties

7.1 Except for Grades N-1 and N-2, one tension test shall be

performed on each heat and the mechanical properties shall

conform to the requirements speciﬁed in Table 2.

7.2 Test coupons may be cut from the heat-treated (if

required) castings at the producer’s option.

8. Retests

8.1 If any specimen is machined improperly or if ﬂaws are

revealed by machining or during testing, the specimen may be

discarded and another substituted from the same heat.

8.2 At the manufacturer’s option, castings may be reheat

treated and retested. When castings are reheat treated, they may

not be re-austenitized more than three times without the

approval of the purchaser. Testing after reheat treatment shall

consist of the full number of specimens taken from locations

complying with the speciﬁcation or order.

9. Rework and Retreatment

9.1 All welds shall be inspected to the same quality stan-

dards as were used to inspect the casting.

9.2 If post-weld heat treatment is required, Class 1 must be

speciﬁed along with the grade, and the welds to be heat treated

must be deﬁned. If post-weld heat treatment is not required,

Class 2 must be speciﬁed along with the grade.

10. Keywords

10.1 castings; general application; steel

TABLE 1 Chemical Composition Requirements

Grade (UNS Number)

Element, %

Carbon

Manganese

Phosphorus Sulfur Silicon

N-1 (J02500) 0.25 0.75 0.035 0.035 0.80

N-2 (J03500) 0.35 0.60 0.035 0.035 0.80

U-60-30 [415-205] (J02500) 0.25 0.75 0.035 0.035 0.80

60-30 [415-205] (J03000) 0.30 0.60 0.035 0.035 0.80

65-35 [450-240] (J03001) 0.30 0.70 0.035 0.035 0.80

70-36 [485-250] (J03501) 0.35 0.70 0.035 0.035 0.80

70-40 [485-275] (J02501) 0.25 1.20 0.035 0.035 0.80

All values are maximums.

Specify Class 1 or Class 2 in addition to grade designation (see 9.2).

For each reduction of 0.01 % carbon below the maximum speciﬁed, an increase of 0.04 % manganese above the maximum speciﬁed will be permitted to a maximum

of 1.40 % for Grade 70-40 [485-275] and 1.00 % for the other grades.

A27/A27M − 20

SUPPLEMENTARY REQUIREMENTS
The following supplementary requirements shall not apply unless speciﬁed in the purchase order. A
list of standardized supplementary requirements for use at the option of the purchaser is included in
Speciﬁcation A781/A781M for sand castings, or in Speciﬁcation A957/A957M for investment
castings. Those which are ordinarily considered suitable for use with this speciﬁcation are given
below. Others enumerated in Speciﬁcation A781/A781M or in Speciﬁcation A957/A957M may be
used with this speciﬁcation upon agreement between the manufacturer and purchaser.
S1. Magnetic Particle Examination
S2. Radiographic Examination
S3. Liquid Penetrant Examination
S4. Ultrasonic Examination
S6. Certiﬁcation
S8. Marking
S9. Charpy Impact Test
S10. Hardness Test
S12. Test Report
S13. Unspeciﬁed Elements
S14. Tension Test from Castings
S51. Permissible Variations in Dimensional Tolerances for
Castings Made from Mounted Patterns
S51.1 Tolerances for commercial steel castings (S51.1.1)
made from mounted patterns and the surfaces that are not to be
machined shall be in accordance with Table S51.1. Metal
match plate patterns and precise molding methods can produce
closer tolerances than the values shown in Table S51.1.
Complex casting designs may require different permissible
variations than those listed in Table S51.1.
S51.1.1 The term “commercial castings” does not cover
castings requiring special ﬁxtures for gaging, or ﬁnishing
castings by grinding to special tolerance gages beyond the
normal requirements as listed in Table S51.1.
S52. Gate and Riser Projections for Castings Made from
Mounted Patterns
S52.1 Castings shall have gates and risers removed in such
a manner that no riser or gate stub projects or a depression is
made beyond or below the casting design contour in an amount
that would exceed the values given in Table S52.1.
TABLE 2 Tensile Requirements
A
Grade
B
Tensile
Strength,
ksi (MPa)
Yield
Strength,
ksi (MPa)
C
Elongation in
2 in. (50 mm),
%
D
Reduction of
Area, %
U-60-30
(415-205)
60 (415) 30 (205) 22 30
60-30
(415-205)
60 (415) 30 (205) 24 35
65-35
(450-240)
65 (450) 35 (240) 24 35
70-36
(485-250)
70 (485) 36 (250) 22 30
70-40
(485-275)
E
70 (485) 40 (275) 22 30
A
All values are minimums.
B
Specify Class 1 or Class 2 in addition to grade designation (see 9.2).
C
Determine by the 0.2 % offset method.
D
When ICI test bars are used in tensile testing as provided for in this speciﬁcation,
the gage length to reduced section diameter ratio shall be 4 to 1.
E
Grade 70-40 [485-275] may be used to meet the requirement of Grade 70-36
[485-250], when agreed upon between the manufacturer and the purchaser.
TABLE S51.1 Normally Expected Deviation of Linear Casting
Dimensions from Design Dimensions
Blueprint Dimension, in. (mm) Tolerances, in. (mm)
Up to 3 (75), incl +
4
⁄
32
(3) −
3
⁄
32
(2)
Over 3 to 7 (75 to 175), incl +
5
⁄
32
(4) −
4
⁄
32
(3)
Over 7 to 20 (175 to 500), incl +
6
⁄
32
(5) −
5
⁄
32
(4)
Over 20 to 100 (500 to 2500), incl +
8
⁄
32
(6) −
6
⁄
32
(5)
TABLE S52.1 Gate and Riser Projection Tolerances
Riser or Gate Maximum
Dimension, in. (mm)
Maximum
Projection,
in. (mm)
Maximum
Depression,
in. (mm)
Up to 4 (100), incl
1
⁄
8
(3)
1
⁄
8
(3)
Over 4 to 8 (100 to 200), incl
1
⁄
4
(6)
1
⁄
8
(3)
Over 8 to 20 (200 to 500), incl
3
⁄
8
(10)
1
⁄
8
(3)
Over 20 to 30 (500 to 750), incl
1
⁄
2
(13)
1
⁄
4
(6)
Over 30 (750)
3
⁄
4
(19)
1
⁄
4
(6)
A27/A27M − 20
3

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摘要：

ASTM A27 - A27M-20 是国际材料与试验协会（ASTM）发布的标准规范，适用于一般用途的碳钢铸件，涵盖从普通碳素钢到中等强度钢的多种等级。该标准为制造、检验和交付提供统一技术要求，包括化学成分、力学性能、热处理条件及验收标准。A27 与 A27M 分别对应英制单位和公制单位两种版本，确保在全球范围内具备兼容性。内容涉及低至中等屈服强度与抗拉强度的碳钢铸件，常用于机械结构、阀门、泵体及矿业设备等工业领域。采用该标准可有效保障铸件质量，并提高供应链的一致性与可追溯性。此文档适用于铸造厂

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