Endorsed by
Manufacturers Standardization Society
of the Valve and Fittings Industry
Used in USNRC-RDT Standards
Standard Specification for
Carbon and Alloy Steel Nuts for Bolts for High Pressure or
High Temperature Service,or Both1
This standard is issued under thefixed designation A194/A194M;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.
1.Scope
1.1This specification2covers a variety of carbon,alloy,and martensitic stainless steel nuts in the size range1⁄4through4in. and metric M6through M100nominal.It also covers austenitic stainless steel nuts in the size range1⁄4in.and M6nominal and above.These nuts are intended for high-pressure or high-temperature service,or both.Grade substitutions without the purchaser’s permission are not allowed.
1.2Bars from which the nuts are made shall be hot-wrought. The material may be further processed by centerless grinding or by cold drawing.Austenitic stainless steel may be solution annealed or annealed and strain-hardened.When annealed and strain hardened austenitic stainless steel is ordered in accor-dance with Supplementary Requirement S1,the purchaser should take special care to ensure that7.
2.2,Supplementary Requirement S1,and Appendix X1are thoroughly understood.
1.3Supplementary requirements(S1through S6)of an optional nature are provided.These shall apply only when specified in the inquiry,contract,and order.
1.4This specification is expressed in both inch-pound units and in SI units.However,unless the order specifies the applicable“M”specification designation(SI units),the mate-rial shall be furnished to inch-pound units.
1.5The values stated in either inch-pound units or SI units are to be regarded separately as standard.Within the text,the 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 noncomformance with the specifi-cation.
2.Referenced Documents
2.1ASTM Standards:
A153/A153M Specification for Zinc Coating(Hot-Dip)on Iron and Steel Hardware3
A276Specification for Stainless Steel Bars and Shapes4 A320/A320M Specification for Alloy-Steel Bolting Ma-terials for Low-Temperature Service5
A370Test Methods and Definitions for Mechanical Testing of Steel Products4
A962/A962M Specification for Common Requirements for Steel Fasteners or Fastener Materials,or Both,Intended for Use at Any Temperature from Cryogenic to the Creep Range5
B633Specification for Electrodeposited Coatings of Zinc on Iron and Steel6
B695Specification for Coatings of Zinc Mechanically Deposited on Iron and Steel6
B696Specification for Coatings of Cadmium Mechanically Deposited6
B766Specification for Electrodeposited Coatings of Cad-mium6
E112Test Methods for Determining Average Grain Size7 2.2American National Standards:8
B1.1Unified Screw Threads
B1.13M Metric Screw Threads
B18.2.2Square and Hex Nuts
B18.2.4.6M Metric Heavy Hex Nuts
3.Terminology
3.1Definitions of Terms Specific to This Standard:
3.1.1Austenitic Grades—All grades with a prefix of“8”or “9”.
3.1.2Ferritic Grades—Grades1,2,2H,2HM,3,4,6,6F,7, 7M,and16.
3.1.3Lot:
3.1.3.1Unless otherwise specified(see3.1.3.2),a lot is the
1This specification is under the jurisdiction of ASTM Committee A01on Steel,
Stainless Steel,and Related Alloys and is the direct responsibility of Subcommittee A01.22on Steel Forgings and Wrought Fittings for Piping Applications and Bolting Materials for Piping and Special Purpose Applications.
Current edition approved Oct.10,2001.Published December2001.Originally published as A194–36T.Last previous edition A194/A194M–01.
2For ASME Boiler and Pressure Vessel Code applications see related Specifi-cation SA-194in Section II of that code.
3Annual Book of ASTM Standards,V ol01.06.
4Annual Book of ASTM Standards,V ol01.03.
5Annual Book of ASTM Standards,V ol01.01.
6Annual Book of ASTM Standards,V ol02.05.
7Annual Book of ASTM Standards,V ol03.01.
8Available from American National Standards Institute,25W.43rd St.,4th Floor,New York,NY10036.
1
Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.quantity of nuts of a single nominal size and grade produced by the same manufacturing process.
3.1.3.2When Supplementary Requirement S5is invoked on the purchase order,the following definitions of a lot shall apply:
For Grade8Nuts—The quantity of all the nuts of a single nominal diameter and grade made from the same heat of steel and made by the same manufacturing process.
For All Other Grade Nuts(see7.2and7.1.2.1)—All the nuts of a single nominal diameter and grade made from the same heat number and heat treated in the same batch if batch-type heat treating equipment is used or heat treated in the same continuous run of not more than8h under the same conditions if continuous-type heat treating equipment is used.
3.1.4For Grade8Nuts—Variations within the grade des-ignated by a letter and differentiated by chemistry and by manufacturing process.
3.1.5For Grade6Nuts—Variations within the grade des-ignated by the letter F as differentiated by chemical additions made for machineability.
3.1.6Series—The dimensional relationship and geometry of the nuts as described in ANSI B18.2.2or B18.2.
4.6M.
4.Ordering Information
4.1The inquiry and order for material under this specifica-tion shall include the following as required to describe the material adequately:
4.1.1Specification designation,year date,and grade,issue date and revision letter,
4.1.2Quantity,number of pieces,
4.1.3Dimensions(see Section8),
4.1.4Options in accordance with7.2.2.1,8.1,8.2,9.3,and 11,and
4.1.5Supplementary Requirements,if any.
4.2Coatings—Coatings are prohibited unless specified by the purchaser.Nuts plated with cadmium or zinc shall be marked as stated in12.2.When coated nuts are ordered,the purchaser should take special care to ensure that Appendix X2 is thoroughly understood.It is the purchaser’s responsibility to specify in the purchase order all information required by the coating facility.Examples of such information may include, but are not limited to,the following:
4.2.1Reference to the appropriate coating specification: Specifications B766,B696,A153/A153M,B695,B633,or other specifications as agreed upon by the purchaser and manufacturer.
4.2.2Requirements for coating thickness and local or batch average thickness measurement,or both.
4.2.3Requirements for selective plating or coating or modi-fication of dimensions to accommodate coating.
4.2.4Requirements for hydrogen embrittlement relief.
4.3See Supplementary Requirement S3for nuts to be used in low temperature applications(Specification A320/A320M).
5.Common Requirements
5.1Material and fasteners supplied to this specification shall conform to the requirements of Specification A962/A962M. These requirements include test methods,finish,thread dimen-sions,marking,certification,optional supplementary require-ments,and others.Failure to comply with the requirements of Specification A962/A962M constitutes nonconformance with this specification.In case of conflict between the requirements of this specification and Specification A962/A962M,this specification shall prevail.
6.Manufacture(Process)
6.1Stainless steels for all types of Grade6and8nuts shall be made by one of the following processes:
6.1.1Electric-furnace(with separate degassing and refining optional),
6.1.2Vacuum induction furnace,or
6.1.3Either of the above followed by electroslag remelting, or consumable-arc remelting.
6.2The steel producer shall exercise adequate control to eliminate excessive unhomogeneity,nonmetallics,pipe,poros-ity,and other defects.
6.3Grades1and2nuts shall be hot or cold forged,or shall be machined from hot-forged,hot-rolled,or cold-drawn bars.
6.3.1All Grade1and2nuts made by cold forging or by machining from cold-drawn bars shall be stress-relief annealed at a temperature of at least1000°F[538°C].
6.3.2Grade1and2nuts made by hot forging or by machining from hot-forged or hot-rolled bars need not be given any stress relief annealing treatment.
6.4Grades2H,2HM,3,4,6,6F,7,7M,and16nuts shall be hot-or cold-forged or shall be machined from hot-forged, hot-rolled,or cold-drawn bars and shall be heat treated to meet the required mechanical properties.These grades shall be reheated above the critical range of the steel,quenched in a suitable medium,and then tempered at a temperature not less than the following:
Grade
Minimum Tempering Temperature,°F
[°C]
2H850[455]
2HM1150[620]
31050[565]
41100[595]
6and6F1100[595]
71100[595]
7M1150[620]
161200[650]
Nuts machined from bar heat treated in accordance with this specification need not be reheat-treated.For Grade2HM and 7M nuts,afinal stress relief shall be done at or above the minimum tempering temperature after all forming,machining, and tapping operations.Thisfinal stress relief may be the tempering operation.
6.4.1Grade6and6F nuts shall be tempered for a minimum of1h at the temperature.
6.5Grades8,8C,8M,8T,8F,8P,8N,8MN,8R,8S,8LN, 8MLN,8MLCuN,and9C nuts shall be hot or cold forged,or shall be machined from hot-forged,hot-rolled or cold-drawn bars.
6.6Grades8A,8CA,8MA,8TA,8FA,8PA,8NA,8MNA, 8RA,8SA,8LNA,8MLNA,8MLCuNA,and9CA nuts shall be hot-or cold-forged or shall be machined from hot-forged, hot-rolled,or cold-drawn bars and the nuts shall subsequently be carbide-solution treated by heating them for a sufficient time at a temperature to dissolve chromium carbides followed
by
cooling at a rate sufficient to prevent reprecipitation of the carbides.
TABLE 1Chemical Requirements A ,B ,C
Grade Symbol Material UNS Number
Carbon,%Manganese,%Phosphorus,%Sulfur,D
%Silicon,%Chromium,
%Nickel,%Molyb-denum,%Tita-nium,
%
Colum-bium and Tanta-lum,%
Nitrogen,
%Other Elements,%1
carbon 0.15min 1.000.0400.0500.40.....................2,2HM,and 2H carbon
0.40min
1.00
0.040
0.0500.40
...
......
............
4
carbon,molyb-denum 0.40–0.500.70–0.900.0350.040
0.15–0.35......
0.20–0.30...
...
...
...
3
Type 501
0.10min 1.000.0400.030 1.00 4.0–6.0...0.40–0.65......
......6Type 410S410000.15 1.000.0400.030 1.0011.5–13.5..................6F Type 416S416000.15 1.250.0600.15min 1.0012.0–14.0..................6F Type 416Se S416230.15
1.25
0.0600.060 1.00
12.0–14.0
......
...
...Selenium,0.15min 7,7M
Type 4140/4142/4145,4140H,4142H,4145H
0.37–0.490.65–1.100.0350.04
0.15–0.350.75–1.20...
0.15–0.25......
...
...
8,8A Type 304S304000.08 2.000.0450.030 1.0018.0–20.08.0–11.0.........
......8C,8CA Type 347S34700
0.08 2.000.0450.030 1.0017.0–19.09.0–12.0......
10x carbon content,min ......
8M,8MA Type 316S316000.08 2.000.0450.030 1.0016.0–18.010.0–14.0 2.00–3.00............8T,8TA Type 321S321000.08 2.000.0450.030 1.0017.0–19.0
9.0–12.0 (5x)
(C+N)min -0.70max
...
......
8F,8FA Type 303S30300
0.15 2.000.200.15min 1.0017.0–19.08.0–10.0...............8F,8FA
Type 303Se
S303230.15 2.000.200.06 1.0017.0–19.08.0–10.0
...
......Selenium,0.15min 8P,8PA Type 305
with restricted carbon
S30500
0.08
2.00
0.045
0.030
1.00
17.0–19.0
11.0–13.0......
...
...
...
8N,8NA Type
304N
S304510.08 2.000.0450.030 1.0018.0–20.08.0–11.0.........0.10–0.168LN,8LNA Type 304LN S304530.030 2.000.0450.030 1.0018.0–20.08.0–11.0
...
...
...0.10–0.168MN,8MNA Type 316N S316510.08 2.000.0450.030 1.0016.0–18.010.0–13.0 2.00–3.00......0.10–0.168MLN,8MLNA Type 316LN S316530.030 2.000.0450.030 1.0016.0–18.010.0–13.0 2.00–3.00......
0.10–0.16
8R,8RA E XM19
S209100.06 4.0–6.00.0450.030 1.0020.5–23.511.5–13.5 1.50–3.00...0.10–0.300.20–0.40Vanadium,
0.10–0.30
8S,8SA
S218000.107.0–9.00.0600.030 3.5–4.516.0–18.08.0–9.0.........0.08–0.188MLCuN,8MLCuNA
S31254S312540.020 1.000.0300.0100.8019.5–20.517.5–18.5 6.0–6.5...
...0.18–0.22Copper,
0.50–1.00
9C,9CA N08367N08367
0.030
2.00
0.040
0.030 1.00
20.0-22.0
23.5-25.5 6.0-7.00.18-0.25Copper
0.75
16
Chromium Molyb-denum Vanadium
0.36–0.470.45–0.700.0350.040
0.15–0.350.80–1.15
...
0.50–0.65...
......Vanadium,
0.25–0.35Aluminum B 0.015
A The intentional addition of Bl,Se,Te,and Pb is not permitted except for Grades 6F,8F,and 8FA,in which Se is specified and required.B
Total aluminum,soluble and insoluble.C
Maximum,unless minimum or range is indicated.D
Because of the degree to which sulfur segregates,product analysis for sulfur over 0.060%max is not technologically appropriate.E
As described in Specification A
276.
7.Mechanical Requirements
7.1Hardness Test :7.1.1Requirements :
7.1.1.1All nuts shall be capable of meeting the hardness requirements specified in Table 2.
7.1.1.2Sample nuts of Grades 1,2,2H,2HM,3,4,7,7M,and 16which have been given the treatment described in 7.1.5shall meet the minimum hardness specified in Table 2.
7.1.2Number of Tests —(Grades 1,2,2H,3,4,7,and 16and all types of Grade 6):
7.1.2.1Tests on the number of sample nuts in accordance with the following table shall be performed by the manufac-turer following all production heat treatments:
Lot Size
Samples
Up to 8001801to 800028001to 220003Over 22000
5
7.1.2.2In addition,a hardness test shall be performed by the manufacturer in accordance with 7.1.5on one sample nut selected from each nominal diameter and series from each grade and heat number following completion of all production heat treatments.
7.1.3Number of Tests,Grades 2HM and 7M :
7.1.3.1The maximum hardness of Grade 2HM and 7M shall be 235HB or 99HRB.Product which has been 100%tested and found acceptable shall have a line under the “M.”7.1.3.2In addition,7.1.2.2shall be met.
7.1.4Number of Tests,All Types of Grade 8—Tests on the number of sample nuts in accordance with 7.1.2.1shall be performed by the manufacturer.
7.1.5Test 2—In addition to the testing required by 7.1.2.1the manufacturer shall also perform hardness tests on sample nuts after the following test heat treatment.After completion of all production heat treatments heat the specimen nuts to the temperatures indicated below for 24h,then slow cool.Test at room temperature.
Grade
Temperature,°F [°C]1
850[455]2,2H,2HM 1000[540]3,4,7,7M 1100[590]16
1200[650]
7.1.5.1Special Requirement,Grades 2HM and 7M —Preparation of Grades 2HM and 7M nuts for hardness test and the hardness test itself shall be performed with consideration to (1)protect legibility of markings;(2)minimize exterior dimen-sional changes;and (3)maintain thread fit.7.2Proof Load Test :
7.2.1Requirements —All nuts shall be capable of withstand-ing the proof loads specified in Table 3and Table 4.However,nuts manufactured to dimensions and configurations other than those covered by ANSI B 1.1,ANSI B 1.13M,ANSI B 18.2.2,and B 18.2.4.6M are not subject to the proof load test.7.2.2Number of Tests :
7.2.2.1Tests on the number of sample nuts in accordance with 7.1.2.1shall be performed by the manufacturer following all production heat treatments except that,unless proof load testing or Supplementary Requirement S1is specified in the order,nuts which would require a proof load in excess of 120000lbf or 530kN may be furnished on the basis of minimum hardness requirements.Proof load testing of nuts requiring a proof load of over 120000lbf or 530kN is covered in Supplementary Requirement S4.
7.2.3Test Method —The test shall be in accordance with Annex A3,Paragraph A3.5.1,of Test Methods and Definitions A 370.
7.3Cone Proof Load Test:
7.3.1Requirements —This test shall be performed only when visible surface discontinuities become a matter of issue between the manufacturer and the purchaser.The requirements specified in Table 5and Table 6shall be met for the size range 1⁄4to 11⁄2in.and M6to M36.Nuts not in this size range and all types of Grade 8nuts are not subject to this test.Also,
TABLE 2Hardness Requirements
Grade and Type
Completed Nuts
Sample Nut after Treatment as in 7.1.5Brinell Hardness
Rockwell Hardness
Brinell Hardness,min Rockwell Hardness B Scale,min
C Scale
B Scale 1121min ...70min 121702159to 352...84min 159842H
248to 35224to 38...179To 11⁄2in.or M36,incl 248to 35224to 38...179Over 11⁄2in.or M36212to 35238max 95min 147792HM and 7M 159to 23722max ...159843,4,7,and 16248to 35224to 38...201946and 6F
228to 27120to 28.........8,8C,8M,8T,8F,8P ,8N,126to 300...60to 105......8MN,8LN,8MLN,8MLCuN,and 9C
126to 300...60to 105......8A,8CA,8MA,8TA,126to 192...60to 90......8FA,8PA,8NA,8MNA,126to 192...60to 90......8LNA,8MLNA,and 8MLCuNA
126to 192...60to 90......8R,8RA,8S,and 8SA 183to 271B 88to C 25
.........9C,9CA
126to 192
...
60to 90
...
...
nuts manufactured to dimensions and configurations other than those covered by ANSI B 1.1,ANSI B 1.13M,ANSI B 18.2.2,and ANSI B 18.2.4.6M are not subject to the cone proof load test.
7.3.2Number of Tests —Sample nuts in accordance with 7.1.2.1shall be tested by the manufacturer.
7.3.3Test Method —The test shall consist of assembling a hardened cone (see Fig.1)and the nut to be tested on a hardened steel mandrel,and applying the proof load specified in Table 5and Table 6.The mandrel shall conform to the requirements of Annex A3,Paragraph A3.5.1of Test Methods and Definitions A 370except that the threads shall be in accordance with ANSI B 1.1of the appropriate thread series,Class 3A fit or ANSI B 1.13M of the appropriate thread pitch,tolerance 4H.The hardened cone shall be as described in Fig.2.The lot shall be considered acceptable if the sample nut withstands application of the proof load without failure.
8.Dimensions
8.1Nuts shall be hexagonal in shape,and in accordance with the dimensions for the hex or heavy hex series,as required,by ANSI B 18.2.2and ANSI B 18.2.4.6M.Unless otherwise specified,the American National Standard Heavy Hex Series shall be used and nuts shall be either double chamfered or have a machined or forged washer face,at the option of the manufacturer,and,conform to the angularity requirements of ANSI B 18.2.2and ANSI B 18.2.4.6M.
8.2Unless otherwise specified,threads shall be in accor-dance with ANSI B 1.1or ANSI B 1.13M,and shall be gaged in accordance with ANSI B 1.2and ANSI B 1.13M as described in 8.2.1and 8.2.2.
8.2.1Nuts up to and including 1in.nominal size shall be UNC Series Class 2B fit.Metric nuts up to and including M24nominal size shall be coarse thread series tolerance 6H.
TABLE 3Proof Load Using Threaded Mandrel —Inch Series
N OTE 1—Proof loads are not design loads.
Nominal Size,in.Threads per Inch Stress Area
in.2
Proof Load,lbf A
Grade 1
Grades 2,2HM,6,6F,7M Grades 2H,3,4,7,16Heavy Hex B
Hex C
Heavy Hex D Hex E Heavy Hex F Hex G
1⁄4200.031130382047704300557047705⁄16
180.05246810629078607070917078603⁄8160.0774100809300116201046013560116207⁄16140.10631382012760159401435018600159401⁄2
130.14191845017030212801916024830212809⁄16
120.1822366021840273002457031850273005⁄8
110.2262938027120339003051039550339003⁄4100.3344342040080501004509058450501007⁄0.4626006055440693006237080850693001
80.606787807272090900
8181010600090900
11⁄880.7901027009480011850010670013820011850011⁄48 1.00013000012000015000013500017500015000013⁄88 1.23316020014800018500016650021580018500011⁄28
1.492
194
000
170
040
223800201
400
261
100
223800
All Types of Grade 8,Grades 9C and 9CA
Heavy Hex H
Hex I
1⁄4200.0316254023805⁄16180.0524419039303⁄8160.0774620058107⁄
16140.1063850079701⁄
2
130.141911*********⁄
16120.18214560136505⁄8
110.22618080169503⁄4100.33426720250507⁄0.46236960346501
80.608480
45450
11⁄880.790632005925011⁄48 1.000800007500013⁄88 1.2339809245011⁄2
8
1.492
119360111900
A See limit for proof load test in 7.2.2.1.The proof load for jam nuts shall be 46%of the tabulated load.B
Based on proof stress of 130000psi.C
Based on proof stress of 120000psi.D
Based on proof stress of 150000psi.E
Based on proof stress of 135000psi.F
Based on proof stress of 175000psi.G
Based on proof stress of 150000psi.H
Based on proof stress of 80000psi.I
Based on proof stress of 75000
psi.
8.2.2Nuts over 1in.nominal size shall be either UNC Series Class 2B fit or 8UN Series Class 2B fit.Unless otherwise specified,the 8UN series shall be furnished.Metric nuts over M24nominal size shall be coarse thread series tolerance 6H.
9.Workmanship,Finish,and Appearance
9.1Nuts shall be free of defects and shall be good commer-cial finish.
9.2If visible surface imperfections in size 1⁄4through 11⁄2in.and M6through M36and in any grade other than Grade 8become a matter of issue between the manufacturer and the purchaser,the cone proof load test described in 7.3shall be employed.
9.3If a scale-free bright finish is required,this shall be specified on the purchase order.
10.Retests
10.1Provisions for retests by the purchaser and his repre-sentative are specified in Supplementary Requirement S2.11.Certification
11.1The producer of nuts shall furnish a certification to the
purchaser or his representative showing the results of the chemical analysis,macroetch examination (Carbon and Alloy Steels Only),mechanical tests,and the minimum tempering temperature for nuts of Grades 2H,2HM,3,4,6,6F,7,and 7M.
11.2Certification shall also include at least the following:11.2.1A statement that the fasteners were manufactured,sampled,tested and inspected in accordance with the specifi-cation and any supplementary requirements or other require-ments designated in the purchase order or contract and was found to meet those requirements.
11.2.2The specification number,year date,and identifica-tion symbol.
12.Product Marking
12.1All nuts shall bear the manufacturer’s identification mark.
12.2Nuts shall be legibly marked on one face to indicate the grade and process of the manufacturer,as presented in Table 7.Marking of wrench flats or bearing surfaces is not permitted unless agreed upon between manufacturer and purchaser.Nuts coated with zinc shall have an asterisk (*)marked after the
TABLE 4Proof Load Using Threaded Mandrel —Metric
N OTE 1—Proof loads are not design loads.
Nominal Size,mm Threads Pitch Stress Area
mm 2
Proof Load,kN A
Grade 1
Grades 2,2HM,6,6F,7M Grades 2H,3,4,7,16Heavy Hex B
Hex C Heavy Hex D
Hex E Heavy Hex F
Hex G M6 1.020.118.016.620.818.729.220.8M8 1.2536.632.830.237.934.044.137.9M10 1.5058.051.947.960.053.969.960.0M12 1.7584.375.569.587.378.4101.687.3M14 2.0115.0102.994.9119.0107.0138.6119.0M16 2.0157.0140.5129.5162.5146.01.2162.5M20 2.5245.0219.3202.1253.6227.8295.2253.6M22 2.5303.0271.2249.9313.6281.8365.1313.6M24 3.0353.0315.9291.2365.4328.3425.4365.4M27 3.0459.0411.0378.7475.1426.9553.4475.1M30 3.5561.0502.1462.8580.6521.7676.0580.6M36
4.0
817.0
731.2
674.0
845.6
759.8
984.5
845.6
All Types of Grade 8,and Grades 9C and 9CA
Nominal Size,mm
Thread Pitch
Stress Area,mm 2Heavy Hex H
Hex I
M6 1.020.111.110.4M8 1.2536.620.118.8M10 1.5058.031.929.9M12 1.7584.346.443.4M14 2.0115.063.359.2M16 2.0157.086.480.9M20 2.5245.0134.8126.2M22 2.5303.0166.7156.0M24 3.0353.0194.2181.8M27 3.0459.0252.5236.4M30 3.5561.0308.6288.9M36
4.0817.0
449.4420.8
A See limit for proof load test in 7.2.2.1.The proof load for jam nuts shall be 46%of the tabulated load.B
Based on proof stress of 5MPa.C
Based on proof stress of 825MPa.D
Based on proof stress of 1035MPa.E
Based on proof stress of 930MPa.F
Based on proof stress of 1205MPa.G
Based on proof stress of 1035MPa.H
Based on proof stress of 550MPa.I
Based on proof stress of 515
MPa.
grade symbol.Nuts coated with cadmium shall have a plus sign (+)marked after the grade symbol.
12.3For purposes of identification marking,the manufac-turer is considered the organization that certifies the fastener
was manufactured,sampled,tested,and inspected in accor-dance with the specification and the results have been deter-mined to meet the requirements of this specification.
TABLE 5Proof Load Using 120°Hardened Steel Cone —Inch A
Nominal Size,in.
Threads per Inch Stress Area
in.2
Proof Load,lbf
Grade 1
Grades 2,2HM,6,6F,7M Grades 2H,3,4,7,16Heavy Hex B
Hex C Heavy Hex D Hex E Heavy Hex F Hex D 1⁄4200.03183800355044004000515044005⁄16180.052461505700710000830071003⁄8160.077450825010300930012000103007⁄16140.10631200011100138501245016150138501⁄
2130.14191570014500181001630021100181009⁄
16
120.1821965018150227002040026500227005⁄8110.2262390022050275502480032150275503⁄4
100.3343365031050388503495045300388507⁄0.462443004090051100466005965051100180.60655150509006365057300742506365011⁄880.79068000628007850070650916007850011⁄48 1.000812507500093750844001093509375013⁄88 1.23394250869501087509780012685010875011⁄2
8
1.492
106700
98500
123100
110800
143600
123100
A
Based upon the following equation (this equation cannot be used for extrapolating values beyond the size ranges listed in this table):
CPL 5~120.30D !3f 3As
where:CPL =cone stripping proof load lbf,
D =nominal diameter of nut,in.,
f =minimum proof stress of nut,psi;see footnote b ,c ,d ,e ,and f ,As =tensile stress area of nut,in.2=0.7854[D -0.9743/n]2,and n =
threads per inch.
B Based on proof stress of 130000psi.C
Based on proof stress of 120000psi.D
Based on proof stress of 150000psi.E
Based on proof stress of 135000psi.F
Based on proof stress of 175000psi.
TABLE 6Proof Load Using 120°Hardened Steel Cone —Metric A
Nominal Size,mm Thread Pitch Stress Area
mm 2
Proof Load,kN
Grade 1
Grades 2,2HM,66F,7M Grades 2H,3,4,7,16Heavy Hex B
Hex C Heavy Hex D
Hex E Heavy Hex F
Hex D M6 1.020.116.915.419.317.322.519.3M8 1.2536.629.627.334.230.839.934.2M10 1.5058.045.742.152.847.561.552.8M12 1.7584.3.659.574.767.186.974.7M14 2.0115.085.678.999.088.9115.399.0M16 2.0157.0113.5104.7131.2118.0152.9131.2M20 2.5245.0166.6153.6192.7173.2224.4192.7M22 2.5303.0199.6183.9230.8207.4268.7230.8M24 3.0353.0224.9207.4260.1233.7302.9260.1M27 3.0459.0277.7256.0321.1288.6373.9321.1M30 3.5561.0321.3296.2371.6334.0432.6371.6M36
4.0
817.0
415.3
382.8
480.3
431.6
559.2
480.3
A
Based upon the following equation (this equation cannot be used for extrapolating values beyond the size ranges listed in this table):
CPL 5~120.012D !3f 3As 30.001
where:CPL =cone stripping proof load lbf [kN],
D =nominal diameter of nut,in.[mm],
f =minimum proof stress of nut,psi [MPa];see footnote b ,c ,d ,e ,and f ,As =tensile stress area of nut,mm 2=0.7854[D -0.9382P]2,and n =
thread pitch,mm.
B Based on proof stress of 5MPa.C
Based on proof stress of 825MPa.D
Based on proof stress of 1035MPa.E
Based on proof stress of 930MPa.F
Based on proof stress of 1205
MPa.
13.Keywords
13.1bolting;chemical analysis;coated;marking on fasten-ers;
plated
FIG.1Application of Hardened Steel Cone to Testing of
Nuts
FIG.2Hardened Steel Cone TABLE 7Marking of Nuts
Grade and Type Nuts Hot-Forged or Cold-Punched Nuts Machined from Bar Stock Nuts Manu-factured in Accordance with 6.6111B ...222B ...2H A 2H 2HB ...2HM A 2HM 2HMB ...333B ...444B ...4L B 4L 4BL ...666B ...6F 6F 6FB ...777B ...7L B 7L 7BL ...7M
A 7M 7M
B ...888B 8A 8
C 8C 8CB 8CA 8M 8M 8MB 8MA 8T 8T 8TB 8TA 8F 8F 8FB 8FA 8P 8P 8PB 8PA 8N 8N 8NB 8NA 8MN 8MN 8MNB 8MNA 8R 8R 8RB 8RA 8S 8S 8SB 8SA 8LN 8LN 8LNB 8LNA 8MLN 8MLN 8MLNB 8MLNA 8MLCuN 8MLCuN 8MLCuNB 8MLCuNA 9C 9C 9CB 9CA
16
16
16B
A The letters H and M indicate heat-treated nuts (see Section 6).B
See Supplementary Requirement S3.
SUPPLEMENTARY REQUIREMENTS
One or more of the following supplementary requirements shall be applied only when specified by the purchaser in the inquiry,contract,or order.Details of these supplementary requirements shall be agreed upon in writing by the manufacturer and purchaser.Supplementary requirements shall in no way negate any requirement of the specification itself.
S1.Strain-Hardened Austenitic Steel Nuts
S1.1Strain hardened Grades 8,8C,8T,8M,8F,8P,8N,or 8MN nuts may be specified.When Supplementary Require-ment S1is invoked in the order,nuts shall be machined from cold drawn bars or shall be cold forged to shape.No subse-quent heat treatment shall be performed on the nuts.Nuts made in accordance with this requirement shall be proof load tested in accordance with 7.2.2.1and shall withstand the proof load specified in Table 8and Table 9.For nuts requiring proof loads over 120000lbf or 530kN,Supplementary Requirement S4is invoked.The hardness limits of Table 2do not apply to strain hardened nuts.Nuts made in accordance with this requirement shall be marked with the Grade symbol underlined.
S2.Retests by Purchaser’s Representative
S2.1The purchaser’s representative may select two nuts per keg (200-lb unit [90-kg])for sizes 5⁄8in.and M16and smaller,one nut per keg for sizes over 5⁄8in.and M16up to and including 11⁄2in.and M36,and one nut per every two kegs for sizes larger than 11⁄2in.and M36,which shall be subjected to the tests specified in Section 7.
S3.Low-Temperature Requirements for Grade 4or Grade 7Nuts
S3.1When low-temperature requirements are specified for Grade 4or Grade 7nuts,the Charpy test procedures and requirements as defined in Specification A 320/A 320M for
Grade L7shall apply.Depending on the size of nuts,separate test samples of the same heat may be required and shall be processed through heat treatment with the nuts for which the test is to apply.Full-size impact specimens cannot be obtained if the bar stock is smaller than 5⁄8in.in diameter or 16M in diameter.
S3.2An“L”shall be added to the marking,as shown in Table 7,for nuts so tested.
S4.Proof Load Tests of Large Nuts
S4.1Proof load testing of nuts requiring proof loads of over 120000lbf or 530kN may be required.When specified,the test is to be performed in accordance with 7.2to the loads required by Table 10and Table 11.The maximum load will be based entirely on the equipment available.
S5.Control of Product by Heat Number
S5.1When control of nuts by actual heat analysis is required and this supplementary requirement is specified,the manufacturer shall identify the completed nuts in each ship-ment by the actual heat number.When this supplementary requirement is specified,a certificate including the results of the actual production tests of each test lot together with the heat chemical analysis shall be furnished by the manufacturer.S6.Grain Size Requirements for Non H Grade Austenitic Steels Used Above 1000°F
S6.1For design metal temperatures above 1000°F [540°C],
TABLE 8Proof Load Testing of Strain Hardened Nuts Using Threaded Mandrel —Inch Series
N OTE 1—Proof loads are not design loads.
Proof Load,lbf A
Nominal Size,in.
Threads per in.
Stress Area,
in.2
Grade 8M (strain hardened)Grade 8M (strain hardened)
All Other Types of Grade 8(strain hardened)All Other Types of Grade 8(strain hardened)
Heavy Hex B
Hex C Heavy Hex D
Hex B 1⁄4200.031634803160395034805⁄16180.052357605240655057603⁄8160.077485107740967585107⁄
16140.1063116901063013290116901⁄
2
130.1419156101419017740156109⁄
16120.182200201820022750200205⁄8
110.226248602260028250248603⁄4100.334367403340041750367407⁄0.462462004158053130462001
80.60660600
54540
69690
60600
11⁄880.7907505067150829507505011⁄48 1.00095000850001050009500013⁄88 1.23311097098012330011097011⁄2
8
1.492
134280119360149200134280
A The proof load for jam nuts shall be 46%of the tabulated value.
B
Based on proof stress of 110000psi up to 3⁄4in.;100000psi 7⁄8to 1in.;95000psi 11⁄8to 11⁄4in.;90000psi 13⁄8to 11⁄2in.C
Based on proof stress of 100000psi up to 3⁄4in.;90000psi 7⁄8to 1in.;85000psi 11⁄8to 11⁄4in.;80000psi 13⁄8to 11⁄2in.D
Based on proof stress of 125000psi up to 3⁄4in.;115000psi 7⁄8to 1in.;105000psi 11⁄8to 11⁄4in.;100000psi 13⁄8to 11⁄2
in.
the material shall have a grain size of No.7or coarser as determined in accordance with Test Methods E 112.The grain
size so determined shall be reported on the Certificate of Test.
TABLE 9Proof Load Testing of Strain Hardened Nuts Using Threaded Mandrel —Metric
N OTE 1—Proof loads are not design loads.
Proof Load,kN A
Nominal Size,mm
Thread Pitch
Stress Area,
mm 2
Grade 8M (strain hardened)Grade 8M (strain hardened)
All Other Types of Grade 8(strain hardened)All Other Types of Grade 8(strain hardened)
Heavy Hex B
Hex C Heavy Hex D
Hex B M6 1.020.115.313.917.315.3M8 1.2536.627.825.331.327.8M10 1.5058.044.140.049.944.1M12 1.7584.3.158.272.5.1M14 2.0115.087.479.498.987.4M16 2.0157.0119.3108.3135.0119.3M20 2.5245.0186.2169.0210.9186.2M22 2.5303.0209.0187.9240.9209.0M24 3.0353.0243.5218.9280.6243.5M27 3.0459.0300.6268.5332.7300.6M30 3.5561.0367.5328.2406.7367.5M36
4.0817.0506.5
449.4
563.7
506.5
A The proof load for jam nuts shall be 46%of the tabulated value.
B
Based on proof stress of 760MPa up to M20mm;690MPa M22to M24mm;655MPa M27to M30;and 620MPa for M36.C
Based on proof stress of 690MPa up to M20mm;620MPa M22to M24mm;585MPa M27to M30;and 550MPa for M36.D
Based on proof stress of 860MPa up to M20mm;795MPa M22to M24mm;725MPa M27to M30mm;and 690MPa for M36.
TABLE 10Proof Load for Large Heavy Hex Nuts —Inch A
Nominal Size,in.Threads per in.
Stress Area,
in.2
Proof Load,lbf B
Grade 1Heavy Hex
Grades 2,6,6F Heavy Hex
Grades 2H,3,4,7,16
Heavy Hex
15⁄88 1.7823140026700031150013⁄48 2.08270400312000300017⁄88 2.4131330036150042180028 2.7736010041550048480021⁄48 3.56280053400062300021⁄28 4.4457720066600077700023⁄4
8
5.43
705
900
814
500
950250
A ANSI B18.2.2in the size range over 11⁄2in.provides dimensions only for heavy hex nuts.Refer to 7.3.1.
B
Proof loads for nuts of larger dimensions or other thread series may be calculated by multiplying the thread stress area times the proof stress in the notes to Table 3or Table 8.The proof load for jam nuts shall be 46%of the tabulated load.
TABLE 11Proof Load for Large Heavy Hex Nuts —Metric A
Nominal Size,mm Thread Pitch Stress Area,
mm 2
Proof Load,kN B
Grade 1Heavy Hex
Grades 2,6,6F Heavy Hex
Grades 2H,3,4,7,16
Heavy Hex
M42 4.511201002.41159.21771.4M48514701315.71521.41771.4M56 5.520301816.92101.02446.2M626802398.62773.83229.4M72
6
3460
3096.7
3581.1
4169.3
A ANSI
B 18.2.4.6M in the size range over M36provides dimensions only for heavy hex nuts.Refer to 7.3.1.
B
Proof loads for nuts of larger dimensions or other thread series may be calculated by multiplying the thread stress area times the proof stress in the notes to Table 3or Table 8.The proof load for jam nuts shall be 46%of the tabulated
load.
(Nonmandatory Information)
X1.STRAIN HARDENING OF AUSTENITIC STEELS
X1.1Strain hardening is the increase in strength and hardness that results from plastic deformation below the recrystallization temperature(cold work).This effect is pro-duced in austenitic stainless steels by reducing oversized bars to the desiredfinal size by cold drawing or other process.The degree of strain hardening achievable in any alloy is limited by its strain hardening characteristics.In addition,the amount of strain hardening that can be produced is further limited by the variables of the process,such as the total amount of cross-section reduction,die angle and bar size.In large diameter bars, for example,plastic deformation will occur principally in the outer regions of the bar,so that the increased strength and hardness due to strain hardening is achieved predominantly near the surface of the bar.That is,the smaller the bar,the greater the penetration of strain hardening.Thus,the mechani-cal properties of a given strain hardened fastener are dependent not just on the alloy,but also on the size of bar from which it is machined.
X2.COATINGS AND APPLICATION LIMITS
X2.1Use of coated fasteners at temperatures above ap-proximately one-half the melting point(Fahrenheit or Celsius) of the coating is not recommended unless consideration is given to the potential for liquid and solid metal embrittlement, or both.The melting point of elemental zinc is approximately 780°F[415°C].Therefore,application of zinc coated fasteners should be limited to temperatures less than390°F[210°C].The melting point of cadmium is approximately600°F[320°C]. Therefore,application of cadmium coated fasteners should be limited to temperatures less than300°F[160°C].
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 everyfive 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,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959, United States.Individual reprints(single or multiple copies)of this standard may be obtained by contacting ASTM at the above address or at610-832-9585(phone),610-832-9555(fax),or service@astm.org(e-mail);or through the ASTM website
(www.astm.org).下载本文
