ASTM A920/A920M-07

This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:A 920/A920M–02a Designation: A 920/A 920M – 07
Standard Specification for
Steel Bars, Microalloy, Hot-Wrought, Special Quality,
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Mechanical Properties
This standard is issued under the fixed designationA920/A920M; 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*
1.1 This specification covers hot-wrought, special quality microalloyed carbon steel bars intended for use in applications where
as-rolled mechanical properties are desired. A typical end use is hydraulic cylinder shafts.
1.2 The bars shall be furnished to chemical composition and mechanical properties as provided herein. Chemical composition
is based on standard carbon steel grades modified to include microalloying elements such as columbium (niobium), vanadium, or
molybdenum. Three strength classes are available, designated 75 [520], 80 [550], and 100 [690], corresponding to the minimum
yield strength in ksi.
1.3 Sections and sizes of bar steels available are covered in Specification A 29/A 29M/A29M. .
1.4 Supplementary Requirements S1 to S5 are provided for use when additional controls or requirements are desired. These
shall apply only when specified on the purchase order.
1.5 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text and tables,
SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used
independently of the other. Combining values from the two systems may result in nonconformance with the specification.
1.6 Unless the order specifies the applicable “M” specification designation, the material shall be furnished to the inch-pound
units.
2. Referenced Documents
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2.1 ASTM Standards:
A 29/A 29M Specification for Steel Bars, Carbon and Alloy, Hot-Wrought and Cold-Finished, General Requirements for
Specification for Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements for
A 370 Test Methods and Definitions for Mechanical Testing of Steel Products
A 576 Specification for Steel Bars, Carbon, Hot-Wrought, Special Quality2
E 45Practice Test Methods for Determining the Inclusion Content of Steel
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 microalloyed steels, n—microalloyed—carbon steels are carbon steels to which small quantities of certain elements are
added in order to enhance mechanical properties.
3.1.1.1 Discussion—This enhancement of mechanical properties results from control of the temperature and cooling rate during
the hot-rolling process.
4. Ordering Information
4.1 Ordersformaterialsuppliedtothisspecificationshouldincludethefollowing,asrequired,todescribeadequatelythedesired
material:
4.1.1 Quantity (weight or number of bars),
4.1.2 Name of material (hot-rolled microalloyed steel bars),
4.1.3 Dimensions,
4.1.4 ASTM specification number and date of issue,
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This specification is under the jurisdiction ofASTM CommitteeA01 on Steel, Stainless Steel,Steel and RelatedAlloys and is the direct responsibility of Subcommittee
A01.15 on Bars.
Current edition approved September 10, 2002.Nov. 1, 2007. Published December 2002.2007. Originally published asA920/A920M-93. approved in 1993. Last previous
edition approved in 2002 as A 920/A 920M- – 02a.
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For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
, Vol 01.05.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.
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A 920/A 920M – 07
4.1.5 Grade designation or chemical composition limits (see Section 8),
4.1.6 Class,
4.1.7 Type (see 7.1) to designate grain refiner,
4.1.8 Additions to the specification and Supplementary Requirements, if required, and,
4.1.9 End use.
5. General Requirements
5.1 Material furnished under this specification shall conform to the applicable requirements of the current edition of
Specification A 29/A 29M/A29M,, unless otherwise provided herein.
6. Materials and Manufacture
6.1 Melting Practice—The steel shall be produced in accordance with the appl
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