Designation: E

Transcription

1 Designation: E Standard Conversion Tables for Metals Relationship Among Brinell,, Rockwell, Superficial, Knoop, and Scleroscope This standard is issued under the fixed designation E 40; 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. This standard has been approved for use by agencies of the Department of Defense.. Scope. Conversion Table presents data in the Rockwell C hardness range on the relationship among Brinell hardness, hardness, Rockwell hardness, Rockwell superficial hardness, Knoop hardness, and Scleroscope hardness of nonaustenitic steels including carbon, alloy, and tool steels in the as-forged, annealed, normalized, and quenched and tempered conditions provided that they are homogeneous..2 Conversion Table 2 presents data in the Rockwell B hardness range on the relationship among Brinell hardness, hardness, Rockwell hardness, Rockwell superficial hardness, Knoop hardness, and Scleroscope hardness of nonaustenitic steels including carbon, alloy, and tool steels in the as-forged, annealed, normalized, and quenched and tempered conditions provided that they are homogeneous..3 Conversion Table 3 presents data on the relationship among Brinell hardness, hardness, Rockwell hardness, Rockwell superficial hardness, and Knoop hardness of nickel and high-nickel alloys (nickel content over 50 %). These hardness conversion relationships are intended to apply particularly to the following: nickel-aluminum-silicon specimens finished to commercial mill standards for hardness testing, covering the entire range of these alloys from their annealed to their heavily cold-worked or age-hardened conditions, including their intermediate conditions..4 Conversion Table 4 presents data on the relationship among Brinell hardness, hardness, Rockwell hardness, and Rockwell superficial hardness of cartridge brass..5 Conversion Table 5 presents data on the relationship between Brinell hardness and Rockwell B hardness of austenitic stainless steel plate in the annealed condition..6 Conversion Table 6 presents data on the relationship between Rockwell hardness and Rockwell superficial hardness of austenitic stainless steel sheet. These conversion tables are under the jurisdiction of ASTM Committee E28 on Mechanical Testing and are the direct responsibility of Subcommittee E28.06 on Indentation Testing. Current edition approved Jan. 0, Published February Originally published as E Last previous edition E e3..7 Conversion Table 7 presents data on the relationship among Brinell hardness, hardness, Rockwell hardness, Rockwell superficial hardness, and Knoop hardness of copper..8 Conversion Table 8 presents data on the relationship among Brinell hardness, Rockwell hardness, and hardness of alloyed white iron..9 Conversion Table 9 presents data on the relationship among Brinell hardness, hardness, Rockwell hardness, and Rockwell superficial hardness of wrought aluminum products..0 Many of the conversion values presented herein were obtained from computer-generated curves of actual test data. Most Rockwell hardness numbers are presented to the nearest 0. or 0.5 hardness number to permit accurate reproduction of these curves. Since all converted hardness values must be considered approximate, however, all converted Rockwell hardness numbers shall be rounded to the nearest whole number in accordance with Practice E 29.. Appendix X-Appendix X9 contain equations developed from the data in Tables -9, respectively, to convert from one hardness scale to another. Since all converted hardness values must be considered approximate, however, all converted hardness numbers shall be rounded in accordance with Practice E Conversion of hardness values should be used only when it is impossible to test the material under the conditions specified, and when conversion is made it should be done with discretion and under controlled conditions. Each type of hardness test is subject to certain errors, but if precautions are carefully observed, the reliability of hardness readings made on instruments of the indentation type will be found comparable. Differences in sensitivity within the range of a given hardness scale (for example, Rockwell B) may be greater than between two different scales or types of instruments. The conversion values, whether from the tables or calculated from the equations, are only approximate and may be inaccurate for specific application. 2. Referenced Documents 2. ASTM Standards: Copyright ASTM International, 00 Barr Harbor Drive, PO Box C700, West Conshohocken, PA , United States.

2 E 40 E 0 Test Method for Brinell of Metallic Materials 2 E 8 Test Method for Rockwell and Rockwell Superficial of Metallic Materials 2 E 29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications 3 E 92 Test Method for of Metallic Materials 2 E 384 Test Method for Microhardness of Materials 2 E 448 Practice for Scleroscope Testing of Metallic Materials 2 3. Methods for Determinations 3. The hardness readings used with these conversion tables shall be determined in accordance with one of the following ASTM test methods: 3.. Test Method E Brinell Test Method E Rockwell Test Method E 8 s A, B, C, D, E, F, G, H, K, 5-N, 30-N, 45-N, 5-T, 30-T, 45-T, 5-W Knoop Test Method E Scleroscope 4 Practice E Apparatus and Reference Standards 4. The apparatus and reference standards shall conform to the description in Test Methods E 92, E 0, E 8, E 384, and Practice E Principle of Method of Conversion 5. Tests have proved that even the most reliable data cannot be fitted to a single conversion relationship for all metals. Indentation hardness is not a single fundamental property but a combination of properties, and the contribution of each to the hardness number varies with the type of test. The modulus of elasticity has been shown to influence conversions 2 Annual Book of ASTM Standards, Vol Annual Book of ASTM Standards, Vol Registered trademark of the Shore Instrument and Manufacturing Co., Inc. at high hardness levels; and at low hardness levels conversions between hardness scales measuring depth and those measuring diameter are likewise influenced by differences in the modulus of elasticity. Therefore separate conversion tables are necessary for different materials. NOTE conversion values for other metals based on comparative test on similar materials having similar mechanical properties will be added to this standard as the need arises. 6. Significance and Use 6. The conversion values given in the tables, or calculated by the equations given in the appendixes, should only be considered valid for the specific materials indicated. This is because conversions can be affected by several factors, including the material alloy, grain structure, heat treatment, etc. 6.2 Since the various types of hardness tests do not all measure the same combination of material properties, conversion from one hardness scale to another is only an approximate process. Because of the wide range of variation among different materials, it is not possible to state confidence limits for the errors in using a conversion chart. Even in the case of a table established for a single material, such as the table for cartridge brass, some error is involved depending on composition and methods of processing (see Appendix X). 6.3 Because of their approximate nature, conversion tables must be regarded as only an estimate of comparative values. It is recommended that hardness conversions be applied primarily to values such as specification limits, which are established by agreement or mandate, and that the conversion of test data be avoided whenever possible. 7. Reporting of s 7. When reporting converted hardness numbers the measured hardness and test scale shall be indicated in parentheses as in the following example: 353 HBW ~38 HRC! () 8. Keywords 8. conversion; hardness scale; metallic 2

3 E 40 Rockwell C 50 kgf (HRC) TABLE Approximate Conversion s for Non-Austenitic Steels (Rockwell C Range) A, B Brinell C 0-mm Standard, 3000-kgf (HBS) 0-mm Carbide, 3000-kgf (HBW) Knoop, 500-gf and Over (HK) Rockwell A, 60-kgf (HRA) D, 00-kgf (HRD) Rockwell Superficial 5-N, 5-kgf (HR 5-N) 30-N, 30-kgf (HR 30-N) 45-N, 45-kgf (HR 45-N) Scleroscope D (739) (722) (705) (688) (670) (654) (500) (487) (475) (464) A In the table headings, force refers to total test forces. B Appendix X contains equations converting determined hardness scale numbers to Rockwell C hardness numbers for non-austenitic steels. Refer to. before using conversion equations. C The Brinell hardness numbers in parentheses are outside the range recommended for Brinell hardness testing in 8. of Test Method E 0. D These Scleroscope hardness conversions are based on Scleroscope hardness relationships developed from hardness data provided by the National Bureau of Standards for 3 steel reference blocks, Scleroscope hardness values obtained on these blocks by the Shore Instrument and Mfg. Co., Inc., the Roll Manufacturers Institute, and members of this institute, and also on hardness conversions previously published by the American Society for Metals and the Roll Manufacturers Institute. Rockwell C 50 kgf (HRC) 3

4 Rockwell B, 00-kgf TABLE 2 Approximate Conversion s for Non-Austenitic Steels (Rockwell B Range) A, B Brinell, 3000-kgf, (HBS) Knoop, 500-gf, and Over (HK) Rockwell A, 60-kgf, (HRA) Rockwell F, 60-kgf, (HRF) Rockwell Superficial 5-T, 5-kgf, (HR 5-T) 30-T, 30-kgf, (HR 30-T) 45-T, 45-kgf, (HR 45-T) Rockwell B, 00-kgf, Rockwell B, 00-kgf, Brinell, 3000-kgf, 0-mm Knoop, 500-gf and Over Rockwell A, 60-kgf, E 40 Rockwell F, 60-kgf, 6-in. (.588- Rockwell Superficial 5-T, 5-kgf, 6-in. ( T, 30-kgf, 6-in. ( T, 45-kgf, 6-in. (.588- Rockwell B, 00-kgf, 6-in. (

5 Rockwell B, 00-kgf, Brinell, 3000-kgf, 0-mm Knoop, 500-gf and Over TABLE 2 Rockwell A, 60-kgf, E 40 Continued Rockwell F, 60-kgf, 6-in. (.588- Rockwell Superficial 5-T, 5-kgf, 6-in. ( T, 30-kgf, 6-in. ( T, 45-kgf, 6-in. (.588- Rockwell B, 00-kgf, 6-in. ( A In table headings, kgf refers to total test force. B Appendix X2 contains equations converting determined hardness numbers to Rockwell B hardness numbers for non-austenitic steels. Refer to. before using conversion equations. 5

6 A, B, C TABLE 3 Approximate Conversion s for Nickel and High-Nickel Alloys NOTE See Supplement to Table 3. NOTE 2 The use of hardness scales for hardness values shown in parentheses is not recommended since they are beyond the ranges recommended for accuracy. Such values are shown for comparative purposes only, where comparisons may be desired and the recommended machine and scale are not available. Brinell Rockwell Rockwell Superficial Indenter, 5, 0, 30- kgf 0-mm Standard, kgf (HBS) A B C D E F G K 60-kgf (HRA) 00-kgf 6-in. ( kgf (HRC) 00-kgf (HRD) 00-kgf 8-in. (3.75- (HRE) 60-kgf 6-in. (.588- (HRF) 50-kgf 6-in. (.588- (HRG) 50-kgf 8-in. (3.75- (HRK) 5-N 5-kgf Superficial (HR 5-N) 30-N 30-kgf Superficial (HR 30-N) 45-N 45-kgf Superficial (HR 45-N) 5-T 5-kgf 6-in. (.588- (HR 5-T) 30-T 30-kgf 6-in. (.588- (HR 30-T) 45-T 45-kgf 6-in. (.588- (HR 45-T) 6 53 (479) (06) (6.5) (04) (5.5) (02) (4.5) (3.0) (2.0) (7.0) (.0) (4.5) (0.0) (2.0) (08.5) (9.0) 32.0 (08.5) (07.5) (6.5) 30.0 (07.0) (06.5) (4.0) 28.0 (06.0) (05.0) (2.0) 26.5 (04.5) (04.0) ( 0.5) (03.0) (03.0) (02.0) (0.5) (00.5) (00.5) (9.0) (7.5) (6.0) (4.5) (3.0) (.5) (0.0) (8.0) E 40

7 E 40 TABLE 3 Continued Brinell Rockwell Rockwell Superficial Indenter, 5, 0, 30- kgf 0-mm Standard, kgf (HBS) A B C D E F G K 60-kgf (HRA) 00-kgf 6-in. ( kgf (HRC) 00-kgf (HRD) 00-kgf 8-in. (3.75- (HRE) 60-kgf 6-in. (.588- (HRF) 50-kgf 6-in. (.588- (HRG) 50-kgf 8-in. (3.75- (HRK) 5-N 5-kgf Superficial (HR 5-N) 30-N 30-kgf Superficial (HR 30-N) 45-N 45-kgf Superficial (HR 45-N) 5-T 5-kgf 6-in. (.588- (HR 5-T) 30-T 30-kgf 6-in. (.588- (HR 30-T) 45-T 45-kgf 6-in. (.588- (HR 45-T) (.5) 7

8 E 40 TABLE 3 Continued Knoop Indenter,5,0,30-kgf Knoop Indenter 500 and 000-gf (HK) A In table headings, kgf or gf refers to total test force. B Appendix X3 contains equations converting determined hardness scale numbers to hardness numbers for nickel and high-nickel alloys. Refer to. before using conversion equations. C Note that in Table 5 of Test Method E 0 (appears in the Annual Book of ASTM Standards, Vol 03.0), the use of a 3000-kgf force is recommended (but not mandatory) for material in the hardness range from 96 to 600 HV, and a 500-kgf force is recommended (but not mandatory) for material in the hardness range from 48 to 300 HV. These recommendations are designed to limit impression diameters to the range from 2.50 to 6.0 mm. The Brinell hardness numbers in this conversion table are based on tests using a 3000-kgf force. When the 500-kgf force is used for the softer nickel and high-nickel alloys, these conversion relationships do not apply. 8

9 TABLE 4 Approximate Conversion s for Cartridge Brass (70 % Copper 30 % Zinc Alloy) A,B Rockwell B, 00- kgf, 6-in. (.588- F, 60-kgf 6-in. (.588- (HRF) E 40 5-T, 5-kgf, 6-in. (.588- (HR 5-T) Rockwell Superficial 30-T, 30- kgf, 6-in. (.588- (HR 30-T) 45-T, 45- kgf, 6-in. (.588- (HR 45-T) Brinell kgf, 0-mm (HBS) 9

10 Rockwell B, 00- kgf, 6-in. (.588- F, 60-kgf 6-in. (.588- (HRF) TABLE 4 E 40 Continued 5-T, 5-kgf, 6-in. (.588- (HR 5-T) Rockwell Superficial 30-T, 30- kgf, 6-in. (.588- (HR 30-T) 45-T, 45- kgf, 6-in. (.588- (HR 45-T) Brinell A In table headings, kgf or gf refers to total test force. B Appendix X4 contains equations converting determined hardness scale numbers to hardness numbers for cartridge brass. Refer to. before using conversion equations. 500-kgf, 0-mm (HBS) 0

11 TABLE 5 Approximate Brinell-Rockwell B Conversion s for Austenitic Stainless Steel Plate in Annealed Condition A,B Rockwell, B (00-kgf, 6-in. (.588- ball) E 40 Brinell (3000-kgf, 0-mm ball) (HBS) A In table headings, kgf or gf refers to total test force. B Appendix X5 contains an equation converting determined Brinell hardness numbers to Rockwell B hardness numbers for austenitic steel plate in the annealed condition. Refer to. before using this conversion equation.

12 TABLE 6 Approximate Rockwell Conversion s for Austenitic Stainless Steel Sheet A,B NOTE These conversions are based on interlaboratory tests conducted on the following grades: Types 20, 202, 30, 302, 304, 304L, 305, 36, 36L, 32, and 347. Tempers ranged from annealed to extra hard for Type 30, with a smaller range of tempers for the other types. Test coupon thicknesses ranged from approximately 0. in. (2.5 to in. (.27. C, 50-kgf (HRC) B, 00-kgf, 6-in. (.588- Rockwell A, 60-kgf, (HRA) 5-N, 5-kgf, Superficial (HR 5-N) Rockwell Superficial 30-N, 30-kgf, Superficial (HR 30-N) 45-N, 45-kgf, Superficial (HR 45-N) A, 60-kgf, (HRA) F, 60-kgf, 6-in. (.588- C (HRF) E 40 5-T, 5-kgf, 6-in. (.588- (HR 5-T) 30-T, 30-kgf, 6-in. (.588- (HR 30-T) 45-T, 45-kgf, 6-in. (.588- (HR 45-T) (3.9) (3.2) (2.5) (.8) (.) (0.5) (09.8) (09.) (08.4) (07.8) (07.) (06.4) (05.7) (05.0) (04.4) (03.7) (03.0) (02.3) (0.7) (0.0) (00.3)

13 B, 00-kgf, 6-in. (.588- A, 60-kgf, (HRA) TABLE 6 F, 60-kgf, 6-in. (.588- C (HRF) E 40 Continued 5-T, 5-kgf, 6-in. (.588- (HR 5-T) 30-T, 30-kgf, 6-in. (.588- (HR 30-T) 45-T, 45-kgf, 6-in. (.588- (HR 45-T) Standard deviation C A In table headings, kgf or gf refers to total test force. B Appendix X6 contains equations converting determined hardness numbers to Rockwell C and Rockwell B hardness numbers for austenitic stainless steel sheet. Refer to. before using conversion equations. C Observed standard deviation of the interlaboratory test data about the indicated conversion line. 3

14 E 40 -kgf 00-gf TABLE 7 Approximate Conversion s for Copper, No. 02 to 42 Inclusive A, B -kgf (HK) Knoop 500-gf (HK) 5-T, 5-kgf 6-in. (.588- (HR 5-T) 0.00-in. (0.25- Strip Rockwell Superficial 5-T, 5-kgf 6-in. (.588- (HR 5-T) in. (0.5- Strip 30-T, 30-kgf 6-in. (.588- (HR 30-T) B, 00-kgf 6-in. (.588- Rockwell F, 60-kgf 6-in. (.588- (HRF) 5-T, 5-kgf 6-in. (.588- (HR 5-T) Rockwell Superficial 30-T, 30-kgf 6-in. (.588- (HR 30-T) in. (.02- Strip and Greater 45-T, 45-kgf 6-in. (.588- (HR 45-T) 500-kgf, 0-mm Diameter (HBS) in. (2.03- Strip Brinell 20-kgf 2-mm Diameter (HBS) in. (.02- Strip A In table headings, kgf or gf refers to total test force. B Appendix X7 contains equations converting determined hardness scale numbers to hardness numbers for copper, numbers 02 to 42 inclusive. Refer to. before using conversion equations. 4

15 , HV 50 A, B, C TABLE 8 Approximate Conversion s for Alloyed White Irons Brinell, HBW Rockwell C, HRC E 40, HV 50 Brinell D, HBW Rockwell C, HRC 000 (903) E (886) (868) (850) (833) (85) (798) (780) (762) (745) (727) (70) (692) (674) (657) (639) A Data were generated in an interlaboratory comparison program conducted by American Foundrymen s Society Special Irons Subcommittee, 5-D. Supporting data available on loan from ASTM Headquarters. Request RR: E B In table headings, kgf or gf refers to total test force. C Appendix X8 contains equations converting determined hardness scale numbers to hardness numbers for alloyed white irons. Refer to. before using conversion equations. D Ten-millimetre tungsten carbide ball. E Brinell hardness numbers in parentheses are above the maximum hardness recommended by Test Method E 0 and are presented for information only. Brinell 500-kgf, (0-mm ) (HBS) A, B, C TABLE 9 Approximate Conversion s for Wrought Aluminum Products 5-kgf, B 00-kgf, 6-in. Rockwell E 00-kgf, 8-in. (HRE) H 60-kgf, 8-in. (HRH) 5-T 5-kgf, 6-in. (HR 5-T) Rockwell Superficial 30-T 30-kgf, 6-in. (HR 30-T) 5-W 5-kgf, 8-in. (HR 5-W) A Data were generated in an interlaboratory test program conducted by ASTM Subcommittee E Supporting data available from ASTM Headquarters. Request RR: E B In table headings, kgf or gf refers to total test force. C Appendix X9 contains equations converting determined hardness scale numbers to Brinell numbers for wrought aluminum products. Refer to. before using conversion equations. 5

16 E 40 APPENDIXES (Nonmandatory Information) X. HARDNESS CONVERSION EQUATIONS FOR NON-AUSTENITIC STEELS (DETERMINED HARDNESS SCALE NUMBERS TO ROCKWELL C HARDNESS NUMBERS) X. The following equations were generated from the specific hardness numbers contained in Table and should not be used for converting numbers outside of the defined hardness range. Due to inherent inaccuracies in the conversion process, the converted number should be rounded to the nearest whole number in accordance with Practice E 29. X.. From hardness to Rockwell C hardness: HRC E E202~HV! E205~HV! E03~HV! 2 (X.) X..2 From Brinell hardness (0-mm diameter steel ball, 3000-kgf force) to Rockwell C hardness: HRC E E202~HBS!.44229E2 04~HBS! E04~HBS! 2 (X.2) X..3 From Brinell hardness (0-mm diameter tungsten carbide ball, 3000-kgf force) to Rockwell C hardness: HRC E E20~HBW! E2 05~HBW! E03~HBW! 2 (X.3) X..4 From Knoop hardness (500-gf force and greater) to Rockwell C hardness: HRC E E203~HK !.3729E2 05~HK ! E 04~HK ! 2 R (X.4) X..5 From Rockwell A hardness to Rockwell C hardness: HRC E E 00~HRA! E203~HRA! 2 (X.5) X..6 From Rockwell D hardness to Rockwell C hardness: HRC E0.3093E00~HRD! R (X.6) X..7 From Rockwell 5N hardness to Rockwell C hardness: HRC E E 0~HR5N!2.4837E2 0~HR5N! E204~HR5N! 3 (X.7) X..8 From Rockwell 30N hardness to Rockwell C hardness: HRC E0.079E00~HR30N! R (X.8) X..9 From Rockwell 45N hardness to Rockwell C hardness: HRC E E20~HR45N! (X.9) X..0 From Scleroscope hardness to Rockwell C hardness: HRC E E20~HSc!23.595E2 03~HSc! E02~HSc! 2 R (X.0) X2. HARDNESS CONVERSION EQUATIONS FOR NON-AUSTENITIC STEELS (DETERMINED HARDNESS SCALE NUMBERS TO ROCKWELL B HARDNESS NUMBERS) X2. The following equations were generated from the specific hardness numbers contained in Table 2 and should not be used for converting numbers outside of the defined hardness range. Due to inherent inaccuracies in the conversion process, the converted number should be rounded to the nearest whole number in accordance with Practice E 29. X2.. From hardness to Rockwell B hardness: HRB E E202~HV!2.4855E204~HV! E03~HV! 2 (X2.) X2..2 From Brinell hardness (0-mm diameter steel ball, 3000-kgf force) to Rockwell B hardness: HRB E E202~HBS!2.4855E204~HBS! E03~HBS! 2 (X2.2) X2..3 From Knoop hardness (500-gf force and greater) to Rockwell B hardness: HRB E E20~HK ! E2 04~HK ! E04~HK ! 2 R (X2.3) X2..4 From Rockwell A hardness to Rockwell B hardness: HRB E E00~HRA!2.5007E202~HRA! 2 R (X2.4) X2..5 From Rockwell F hardness to Rockwell B hardness: HRB E0.7567E00~HRF! R (X2.5) 6

17 E 40 X2..6 From Rockwell 5T hardness to Rockwell B hardness: HRB E E00~HR5T! R (X2.6) X2..7 From Rockwell 30T hardness to Rockwell B hardness: HRB E E00~HR30T! R (X2.7) X2..8 From Rockwell 45T hardness to Rockwell B hardness: HRB E E20~HR45T! R (X2.8) X3. HARDNESS CONVERSION EQUATIONS FOR NICKEL AND HIGH-NICKEL ALLOYS (DETERMINED HARDNESS SCALE NUMBERS TO VICKERS HARDNESS NUMBERS) X3. The following equations were generated from the specific hardness numbers contained in Table 3 and should not be used for converting numbers outside of the defined hardness range. Due to inherent inaccuracies in the conversion process, the converted number should be rounded to the nearest whole number in accordance with Practice E 29. X3.. From Brinell hardness (0-mm diameter steel ball, 3000-kgf force) to hardness (.5, 0, and 30-kgf forces): HV.5,0, E E20~HBS!.89707E204~HBS! 2 R (X3.) X3..2 From Rockwell A hardness to hardness (.5, 0, and 30-kgf forces): ~HV.5,0,30! E E204~HRA!.67455E206~HRA! 2 (X3.2) X3..3 From Rockwell B hardness to hardness (.5, 0, and 30-kgf forces): ~HV.5, 0, 30! E E204~HRB! (X3.3) X3..4 From Rockwell C hardness to hardness (.5, 0, and 30-kgf forces): ~HV.5, 0, 30! E E204~HRC! E207~HRC! 2 R (X3.4) X3..5 From Rockwell D hardness to hardness (.5, 0, and 30-kgf forces): ~HV.5, 0, 30! E E204~HRD! E207~HRD! 2 (X3.5) X3..6 From Rockwell E hardness to hardness (.5, 0, and 30-kgf forces): ~HV.5, 0, 30! E E204~HRE! R (X3.6) X3..7 From Rockwell F hardness to hardness (.5, 0, and 30-kgf forces): ~HV.5, 0, 30! E E 04(HRF) (X3.7) R 2 = X3..8 From Rockwell G hardness to hardness (.5, 0, and 30-kgf forces): ~HV.5, 0, 30! E E205~HRG! (X3.8) X3..9 From Rockwell K hardness to hardness (.5, 0, and 30-kgf forces): ~HV.5, 0, 30! E E204~HRK! (X3.9) X3..0 From Rockwell 5N hardness to hardness (.5, 0, and 30-kgf forces): ~HV.5, 0, 30! E E204~HR5N!.75469E206~HR5N! 2 (X3.0) X3.. From Rockwell 30N hardness to hardness (.5, 0, and 30-kgf forces): ~HV.5, 0, 30! E E204~HR30N! E207~HR30N! 2 R (X3.) X3..2 From Rockwell 45N hardness to hardness (.5, 0, and 30-kgf forces): ~HV.5, 0, 30! E E205~HR45N! E207~HR45N! 2 (X3.2) X3..3 From Rockwell 5T hardness to hardness (.5, 0, and 30-kgf forces): ~HV.5, 0, 30! E E204~HR5T! E208~HR5T! 2 R (X3.3) X3..4 From Rockwell 30T hardness to hardness (.5, 0, and 30-kgf forces): ~HV.5, 0, 30! E E204~HR30T! E208~HR30T! 2 (X3.4) X3..5 From Rockwell 45T hardness to hardness (.5, 0, and 30-kgf forces): ~HV.5, 0, 30! E E204~HR45T! E207~HR45T! 2 7

18 E 40 (X3.5) X3..6 From Knoop hardness (500 and 000-gf forces) to hardness (.5, 0, and 30-kgf forces): HV.5, 0, E E20~HK 500,000! R (X3.6) X4. HARDNESS CONVERSION EQUATIONS FOR CARTRIDGE BRASS (DETERMINED HARDNESS SCALE NUMBERS TO VICKERS HARDNESS NUMBERS) X4. The following equations were generated from the specific hardness numbers contained in Table 4 and should not be used for converting numbers outside of the defined hardness range. Due to inherent inaccuracies in the conversion process, the converted number should be rounded to the nearest whole number in accordance with Practice E 29. X4.. From Rockwell B hardness to hardness: ~HV! E E204~HRB! E2 07~HRB! E209~HRB! 3 R (X4.) X4..2 From Rockwell F hardness to hardness: ~HV! E E204~HRF! E2 06~HRF! E208~HRF! 3 (X4.2) X4..3 From Rockwell 5T hardness to hardness: ~HV! E E203~HR5T!.8405E2 05~HR5T! E208~HR5T! 3 (X4.3) X4..4 From Rockwell 30T hardness to hardness: ~HV! E E204~HR30T! E2 08~HR30T! E20~HR30T! 3 (X4.4) X4..5 From Rockwell 45T hardness to hardness: ~HV! E E204~HR45T! E2 07~HR45T! E209~HR45T! 3 (X4.5) X4..6 From Brinell hardness (0-mm diameter steel ball, 500-kgf force) to hardness: HV E E 00~HBS 0/500/5! (X4.6) X5. HARDNESS CONVERSION EQUATION FOR ANNEALED AUSTENITIC STAINLESS STEEL PLATE (DETERMINED BRINELL HARDNESS NUMBERS TO ROCKWELL B HARDNESS NUMBERS) X5. The following equation was generated from the specific hardness numbers contained in Table 5 and should not be used for converting numbers outside of the defined hardness range. Due to inherent inaccuracies in the conversion process, the converted number should be rounded to the nearest whole number in accordance with Practice E 29. X5.. From Brinell hardness (0-mm steel diameter ball, 3000-kgf force) to Rockwell B hardness: HRB E E03~HBS! 2 (X5.) X6. HARDNESS CONVERSION EQUATIONS FOR AUSTENITIC STAINLESS STEEL SHEET (DETERMINED HARDNESS SCALE NUMBERS TO ROCKWELL C OR ROCKWELL B HARDNESS NUMBERS X6. The following equations were generated from the specific hardness numbers contained in Table 6 and should not be used for converting numbers outside of the defined hardness range. Due to inherent inaccuracies in the conversion process, the converted number should be rounded to the nearest whole number in accordance with Practice E 29. X6.. From Rockwell A hardness to Rockwell C hardness: HRC E0.9837E00~HRA! R (X6.) X6..2 From Rockwell 5N hardness to Rockwell C hardness: HRC E E00~HR5N! R (X6.2) X6..3 From Rockwell 30N hardness to Rockwell C hardness: HRC E0.4752E00~HR30N! R (X6.3) X6..4 From Rockwell 45N hardness to Rockwell C hardness: HRC E E20~HR45N! R (X6.4) X6..5 From Rockwell A hardness to Rockwell B hardness: HRB E E00~HRA! R (X6.5) X6..6 From Rockwell F hardness to Rockwell B hardness: 8

19 E 40 HRB E E00~HRF! (X6.6) X6..7 From Rockwell 5T hardness to Rockwell B hardness: HRB E E00~HR5T! R (X6.7) X6..8 From Rockwell 30T hardness to Rockwell B hardness: HRB E0.4388E00~HR30T! R (X6.8) X6..9 From Rockwell 45T hardness to Rockwell B hardness: HRB E E20~HR45T! R (X6.9) X7. HARDNESS CONVERSION EQUATIONS FOR COPPER, NOS. 02 TO 42 INCLUSIVE (DETERMINED HARDNESS SCALE NUMBERS TO VICKERS HARDNESS NUMBERS) X7. The following equations were generated from the specific hardness numbers contained in Table 7 and should not be used for converting numbers outside of the defined hardness range. Due to inherent inaccuracies in the conversion process, the converted number should be rounded to the nearest whole number in accordance with Practice E 29. X7.. From hardness (00-gf force) to hardness (-kgf force): HV E0.7624E00~HV 00! (X7.) X7..2 From Knoop hardness (-kgf force) to hardness (-kgf force): HV 5.858E E20~HK 000!.50709E203~HK 000! 2 (X7.2) X7..3 From Knoop hardness (500 gf force) to hardness (-kgf force): HV E E20~HK 500!.22866E203~HK 500! 2 (X7.3) X7..4 From Rockwell 5T hardness to hardness (-kgf force) for 0.00-in. (0.25- strip: ~HV! E E202~HR5T!.40059E2 04~HR5T! E207~HR5T! 3 R (X7.4) X7..5 From Rockwell 5T hardness to hardness (-kgf force) for in. (0.5- strip: ~HV! E E203~HR5T!4.5450E2 05~HR5T! E207~HR5T! 3 R (X7.5) X7..6 From Rockwell B hardness to hardness (- kgf force) for in. (.02- and greater strip: ~HV! E E204~HRB! E2 07~HRB! E209~HRB! 3 (X7.6) X7..7 From Rockwell F hardness to hardness (- kgf force) for in. (.02- and greater strip: ~HV! E E204~HRF! E2 06~HRF! E208~HRF! 3 (X7.7) X7..8 From Rockwell 5T hardness to hardness (-kgf force) for in. (.02- and greater strip: ~HV! E E203~HR5T!2.4342E2 05~HR5T! E207~HR5T! 3 R (X7.8) X7..9 From Rockwell 30T hardness to hardness (-kgf force) for in. (.02- and greater strip: ~HV! E E204~HR30T!.85833E2 06~HR30T! E209~HR30T! 3 (X7.9) X7..0 From Rockwell 45T hardness to hardness (-kgf force) for in. (.02- and greater strip: ~HV! E E204~HR45T! E2 07~HR45T! E209~HR45T! 3 R (X7.0) X7.. From Brinell hardness (0-mm diameter steel ball, 500-kgf force) to hardness (-kgf force) for in. (2.03- strip: HV E E20~HBS 0/500/5! E204~HBS 0/500/5! 2 (X7.) X7..2 From Brinell hardness (2-mm diameter steel ball, 20-kgf force) to hardness (-kgf force) for in. (.02- strip: HV E E00~HBS 2/20/5! E204~HBS 2/20/5! 2 (X7.2) 9

20 E 40 X8. HARDNESS CONVERSION EQUATIONS FOR ALLOYED WHITE IRON (DETERMINED HARDNESS SCALE NUMBERS TO VICKERS HARDNESS NUMBERS) X8. The following equations were generated from the specific hardness numbers contained in Table 8 and should not be used for converting numbers outside of the defined hardness range. Due to inherent inaccuracies in the conversion process, the converted number should be rounded to the nearest whole number in accordance with Practice E 29. X8.. From Brinell hardness (0-mm diameter tungsten carbide ball, 3000-kgf force) to hardness (50-kgf force): HV E0.3635E00~HBW! R (X8.) X8..2 From Rockwell C hardness to hardness (50-kgf force): HV E E0~HRC! E20~HRC! 2 R (X8.2) X9. HARDNESS CONVERSION EQUATIONS FOR WROUGHT ALUMINUM PRODUCTS (DETERMINED HARDNESS SCALE NUMBERS TO BRINELL HARDNESS NUMBERS) X9. The following equations were generated from the specific hardness numbers contained in Table 9 and should not be used for converting numbers outside of the defined hardness range. Due to inherent inaccuracies in the conversion process, the converted number should be rounded to the nearest whole number in accordance with Practice E 29. X9.. From hardness (5-kgf force) to Brinell hardness (0-mm diameter steel ball, 500-kgf force): HBS 0/500/ E E2 0~HV 5! R (X9.) X9..2 From Rockwell B hardness to Brinell hardness (0- mm diameter steel ball, 500-kgf force): ~HBS 0/500/5! E E204~HRB! E206~HRB! E208~HRB! 3 R (X9.2) X9..3 From Rockwell E hardness to Brinell hardness (0- mm diameter steel ball, 500-kgf force): ~HBS 0/500/5! E E203~HRE! E205~HRE! E208~HRE! 3 R (X9.3) X9..4 From Rockwell H hardness to Brinell hardness (0-mm diameter steel ball, 500-kgf force): ~HBS 0/500/5! E E202~HRH!.02525E204~HRH! E207~HRH! 3 R (X9.4) X9..5 From Rockwell 5T hardness to Brinell hardness (0-mm diameter steel ball, 500-kgf force): ~HBS 0/500/5! E E202~HR5T!.44778E204~HR5T! E207~HR5T! 3 R (X9.5) X9..6 From Rockwell 30T hardness to Brinell hardness (0-mm diameter steel ball, 500-kgf force): ~HBS 0/500/5! E E203~HR30T!.45528E205~HR30T! E208~HR30T! 3 R (X9.6) X9..7 From Rockwell 5W hardness to Brinell hardness (0-mm diameter steel ball, 500-kgf force): ~HBS 0/500/5! E E02~HR5W! E00~HR5W! E202~HR5W! 3 R (X9.7) X0. EFFECT OF STRAIN HARDENING ON HARDNESS CONVERSION RELATIONSHIPS X0. For ferrous and nonferrous metals softer than 240 HB, a single set of hardness conversion relationships inevitably introduces large errors because of the wide difference that may exist in the amount of cold working before testing, as well as the amount that occurs during the test itself. This dependence on strain-hardening characteristics can be demonstrated by the Rockwell scales 5-T, 30-T, 45-T, F, and B, in which forces ranging from 5 to 00 kgf are applied on a 6-in. (.588- diameter ball indenter. As higher forces are used, the increased strain raises the hardness by an amount that depends on the pretest capacity of the metal for strain hardening. An annealed metal of high capacity for strain hardening will harden much more in the test than will a cold-worked metal. For example, an annealed iron and a cold-rolled aluminum alloy may have hardnesses of 7 and 72 HR 5T, respectively. The hardnesses are 3 HRB for the soft annealed iron and 7 HRB for the cold-rolled aluminum alloy. X0.2 On the other hand, if materials have Brinell or Rockwell hardness values that are approximately equal in the annealed state as well as after heavy cold deformation, these materials will have similar hardness conversion relationships 20

21 E 40 for all degrees of strain hardening. This is true of yellow brasses and low-carbon steels and irons. The limiting conditions can usually be identified by the appearance of the hardness indentations themselves. Soft annealed metals have characteristic sinking type indentation contours when indenters of the ball type are used. On the other hand, heavily cold-worked metals have sharp ridging type indentations. While annealed metals are being progressively cold worked, the indentation contours pass through a flat stage in which the lip of the indentation is neither round nor sharply ridged. It is necessary to base hardness conversions on comparative tests of similar materials that also have very similar mechanical properties. ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below. This standard is copyrighted by ASTM International, 00 Barr Harbor Drive, PO Box C700, West Conshohocken, PA , United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at (phone), (fax), or service@astm.org ( ); or through the ASTM website ( 2