INCH-POUND MS31E 23 March 200 MS31D 2 August 184 MILITARY SPECIFICATION SHEET NUT, PLAIN, HEXAGON (JAM) UNC-2B AND UNF-2B Reactivated after 23 March 200 and may be used for new and existing designs and acquisitions. This specification sheet is approved for use by all Departments and Agencies of the Department of Defense. The requirements for acquiring the product described herein shall consist of this specification sheet and FF-N-836. F 30 ±2 H.016 APPROX 30 ±2 H 30 ±2 G OPTIONAL DESIGNS TABLE I. DESIGN CONFIGURATIONS NOMINAL SIZE OR BASIC MAJOR DIAMETER OF THREAD WIDTH ACROSS FLATS P WIDTH ACROSS CORNERS G THICKNESS H MAX MIN MAX MNI MAX MIN 1/4 -.200 /16 -.3 3/8 -.370.437.000.62.428.48.1.0..0.488.7.628.163.1.227.10.180.210 7/16 -.437 1/2 -.000 /16 -.62.687.700.870.67.736.861.74.866 1.010.768.840.82.260.323.324.240.302.301 /8 -.620 3/4 -.700 7/8 -.870.7 1.0 1.3.22 1.088 1.2 1.083 1.2 1.16 1.01 1.240 1.447.387.446.10.363.38.8 1-1.0000 1 1/8-1.0 1 1/4-1.200 1.000 1.687 1.870 1.0 1.631 1.2 1.732 1.4 2.1 1.3 1. 2.066.7.63.71.1.7.687 1 3/8-1.370 1 1/2-1.000 1 3/4-1.700 2.062 2.200 2.620 1.4 2.17 2.38 2.382 2.8 3.031 2.273 2.480 2.8..880 1.00.747.808.2 2-2.0000 2 1/4-2.200 2 1/2-2.000 3.0000 3.370 3.700 2.00 3.262 3.62 3.464 3.8 4.330 3.306 3.71 4. 1.8 1.21 1.0 1.00 1.1 1.401 2 3/4-2.700 3-3.0000 4.0 4.000 3.88 4.30 4.763.16 4.46 4. 1.634 1.763 1.22 1.643 AMSC N/A FSC 310 1 of
ACTIVE FOR NEW DESIGN THE PART NUMBERS IN TABLE II ONLY WILL BE USED FOR DESIGN AND ENGINEERING. TABLE II. DASH NUMBERS THREAD SIZE.200-20UNC-2B.200-28UNF-2B.3-18UNC-2B.3-24UNF-2B COATED 1 2 406 3 4 6 426 7 8 10 06 11 12 14 26 1 16 THREAD SIZE.370-16UNC-2B.370-24UNF-2B.437-14UNC-2B.437-20UNF-2B COATED 17 18 606 1 20 21 22 626 23 24 2 26 706 27 28 2 30 726 31 32 THREAD SIZE.000-UNC-2B.000-20UNF-2B.62-12UNC-2B.62-18UNF-2B COATED 33 34 806 3 36 37 38 826 3 40 42-43 44 46-47 48 THREAD SIZE.620-11UNC-2B.620-18UNF-2B.700-10UNC-2B.700-16UNF-2B COATED 4 0 1006 1 2 3 4 1026 6 7 8 1206 60 61 62 1226 63 64 THREAD SIZE.870-UNC-2B.870-14-UNF-2B 1.0000-8UNC-2B 1.0000-12UNF-2B 66 67 68 70 71 72 73 74 7 76 78 7 80 2
ACTIVE FOR NEW DESIGN THE PART NUMBERS IN TABLE II ONLY WILL BE USED FOR DESIGN AND ENGINEERING. TABLE II. DASH NUMBERS - CONTINUED THREAD SIZE 1.00-7UNC-2B 1.00-12UNF-2B 1.200-7UNC-2B 1.200-12UNF-2B 82 83 84 86 87 88 8 0 1 2 4 6 THREAD SIZE 1.370-6UNC-2B 1.370-12UNF-2B 1.000-6UNC-2B 1.000-12UNF-2B 8 100 102 103 104 10 106 107 108 110 111 112 THREAD SIZE 1.700-UNC-2B 2.0000-4-1/2UNC-2B 2.200-4-1/2UNC-2B 2.000-4UNC-2B 114 11 116 118 11 120 121 122 123 124 126 127 128 THREAD SIZE 2.700-4UNC-2B 3.0000-4UNC-2B MATERIAL DASH NO DASH NO 0 1 2 4 6 1/ SEE REQUIREMENT 2/ SEE REQUIREMENT 3
REQUIREMENTS: 1. MATERIAL: STEEL, CARBON, GRADES B AND C, IN ACCORDANCE WITH PROCUREMENT SPECIFICATION. STEEL, CORROSION RESISTANT, 300 SERIES, IN ACCORDANCE WITH PROCUREMENT SPECIFICATION. IN ACCORDANCE WITH PROCUREMENT SPECIFICATION. 2. PROTECTIVE COATING AND TREATMENT: D, BLACK OXIDE OR COATING, IN ACCORDANCE WITH PROCUREMENT SPECIFICATION. CLEANED, DESCALED AND PASSIVATED, IN ACCORDANCE WITH ASTM A380. NICKEL PLATED, IN ACCORDANCE WITH PROCUREMENT SPECIFICATION. 3. MAGNETIC PERMEABILITY. CORROSION RESISTANT STEEL FASTENERS SHALL HAVE A MAGNETIC PERMEABILITY OF 2.0 MAXIMUM (AIR = 1.0) AT A FIELD STRENGTH OF H = 200 OERSTEDS USING A MAGNETIC INDICATOR PER ASTM A342. 4. THREADS. THREADS SHALL BE IN ACCORDANCE WITH FED-STD-H28/2. ACCEPTABILITY OF SCREW THREADS SHALL BE IN ACCORDANCE WITH FED-STD-H28/20, SYSTEM 21.. PART NUMBER. THE PART NUMBER CONSISTS OF THE BASIC MS SHEET NUMBER, FOLLOWED BY A DASH NUMBER TAKEN FROM TABLE II. EXAMPLE: MS31 1 DASH NUMBER BASIC MS SHEET NUMBER MS31 1 INDICATES NUT, PLAIN, HEXAGON (JAM) THREAD SIZE.200-20UNC-2B, D. 1/ ADD B BEFORE DASH NUMBER FOR CORROSION RESISTANT STEEL NUTS WITH BLACK OXIDE COATING, CLASS 4, IN ACCORDANCE WITH MIL-DTL-24. EXAMPLE: MS31 B 3.200-20UNC-2B BLACK OXIDE COATED CORROSION RESISTANT STEEL BASIC MS SHEET NUMBER 2/ ADD N BEFORE DASH NUMBER FOR BRASS NUTS WITH NICKEL PLATING, IN ACCORDANCE WITH PROCUREMENT SPECIFICATION. EXAMPLE: MS31 N 4.200-20UNC-2B NICKEL PLATED BRASS BASIC MS SHEET NUMBER 4
NOTES: 1. DIMENSIONS ARE IN INCHES. 2. FOR DESIGN USE PART NUMBERS IN TABLE II. 3. FOR PART NUMBERS SEE TABLE III. 4. FOR MAINTENANCE USE INACTIVE PART NUMBERS OF TABLE IV.. FOR INTERCHANGEABILITY BETWEEN THE (GRADE A, ) NUTS AND (GRADE B, ) NUTS, SEE TABLE V. 6. FOR INTERCHANGEABILITY OF OR AND NEW PART NUMBERS, SEE TABLE VI AND TABLE VII. 7. FOR DESIGN FEATURE PURPOSES, THIS STANDARD TAKES PRECEDENCE OVER PROCUREMENT DOCUMENTS REFERENCED HEREIN. 8. CHANGES FROM PREVIOUS ISSUE. MARGINAL NOTATIONS ARE NOT USED IN THIS REVISION TO IDENTIFY CHANGES WITH RESPECT TO THE PREVIOUS ISSUE DUE TO THE EXTENT OF THE CHANGES.
PART NUMBERS THE FOLLOWING PART NUMBERS ARE AFTER 21 MAR 166 TABLE III THREAD SIZE.200-20UNC-2B.200-28UNF-2B.3-18UNC-2B.3-24UNF-2B STEEL, CARBON,GRADE A, 401 402 403 40 42 0 2 STEEL,CARBON, GRADE C, 408 40 CRES, 300-400 SERIES, PASSIVATED 0 430 10 30 TIN PLATED 1 2 431 432 11 12 31 32 THREAD SIZE.370-16UNC-2B.370-24UNF-2B.437-14UNC-2B.437-20UNF-2B STEEL, CARBON, GRADE A, 601 602 603 60 62 70 72 608 60 CRES, 300-400 SERIES PASSIVATED 610 630 710 730 TIN PLATED 611 612 631 632 711-731 - THREAD SIZE.000-UNC-2B.000-20UNF-2B.62-12UNC-2B.62-18UNF-2B STEEL, CARBON, GRADE A, STEEL CARBON, GRADE C, 801 802 803 80-808 80 CRES, 300-400 SERIES, PASSIVATED 0 830 10 0 1 831 11 1 421 422 423 428 42 621 622 623 628 62 821 822 823 82-828 82 01 02 03 08 0 701 702 703 708 70 01 02 03 0 06 08 0 21 22 23 28 2 721 722 723 728 72 21 22 23 2 26 28 2 6
PART NUMBERS THE FOLLOWING PART NUMBERS ARE AFTER 21 MAR 166 TABLE III C0NTINUED THREAD SIZE.620-11UNC-2B.620-18UNF-2B.700-10UNC-2B.700-16UNF-2B STEEL, CARBON,GRADE A, 1001 1002 1003 1021 1022 1023 1201 1202 1203 1221 1222 1223 100 102 120 122 STEEL,CARBON, GRADE C, 1008 100 CRES, 300-400 SERIES, PASSIVATED 0 1030 1210 1230 1 1031 1211 1231 THREAD SIZE.870-UNC-2B.870-14UNF-2B 1.0000-8UNC-2B 1.0000-12UNF-2B STEEL, CARBON, GRADE A, 1401 1402 1403 140 1406 1408 140 CRES, 300-400 SERIES PASSIVATED 10 1430 1610 1630 11 1431 1611 1631 THREAD SIZE 1.0-7UNC-2B 1.0-12UNF-2B 1.200-7UNC-2B 1.200-12UNF-2B STEEL, CARBON, GRADE A, STEEL CARBON, GRADE C, 1801 1802 1803 180 1806 1808 180 CRES, 300-400 SERIES, PASSIVATED 10 1830 2010 2030 11 1831 2011 2031 1028 102 1421 1422 1423 142 1426 1428 142 1821 1822 1823 182 1826 1828 182 1208 120 1601 1602 1603 160 1606 1608 160 2001 2002 2003 200 2006 2008 200 1228 122 1621 1622 1623 162 1626 1628 162 2021 2022 2023 202 2026 2028 202 7
PART NUMBERS THE FOLLOWING PART NUMBERS ARE AFTER 21 MAR 166 TABLE III - CONTINUED THREAD SIZE 1.370-6UNC-2B 1.370-12UNF-2B 1.000-6UNC-2B 1.000-12UNF-2B STEEL, CARBON,GRADE A, STEEL,CARBON, GRADE C, 2201 2202 2203 220 2206 2208 220 CRES, 300-400 SERIES, PASSIVATED 2210 2230 20 2430 2211 2231 21 2431 THREAD SIZE 1.700-UNC-2B 2.0000-4-1/2UNC-2B 2.200-4-1/2UNC-2B 2.000-4UNC-2B STEEL, CARBON, GRADE A, 2801 2802 2803 280 2806 2808 280 CRES, 300-400 SERIES PASSIVATED 20 3210 3610 4010 21 3211 3611 4011 THREAD SIZE 2.700-4UNC-2B 3.0000-4UNC-2B MATERIAL DASH NO DASH NO STEEL, CARBON, GRADE A, STEEL CARBON, GRADE C, 4401 4402 4403 440 4406 4408 440 2221 2222 2223 222 2226 2228 222 3201 3202 3203 320 3206 3208 320 4801 4802 4803 480 4806 4808 480 CRES, 300-400 SERIES, PASSIVATED 40 40 41 2401 2402 2403 240 2406 2408 240 3601 3602 3603 360 3606 3608 360 2421 2422 2423 242 2426 2428 242 4001 4002 4003 400 4006 4008 400 8
INACTIVE PART NUMBERS FOR NEW DESIGN THE FOLLOWING PART NUMBERS IN TABLE IV ARE INACTIVE FOR NEW DESIGN AFTER 21 MAR 166. USE FOR MAINTENANCE PURPOSES ONLY. TABLE IV THREAD SIZE.200-20UNC-2B.200-28UNF-2B.3-18UNC-2B.3-24UNF-2B STEEL, CARBON,GRADE B, 404 424 04 24 407 427 07 27 THREAD SIZE.370-16UNC-2B.370-24UNF-2B.437-14UNC-2B.437-20UNF-2B 604 624 704 724 607 627 707 727 THREAD SIZE.000-UNC-2B.000-20UNF-2B.62-12UNC-2B.62-18UNF-2B 804 824 04 24 807 827 07 27 THREAD SIZE.620-11UNC-2B.620-18UNF-2B.700-10UNC-2B.700-16UNF-2B 1004 1024 1204 1224 1007 1027 1207 1227 THREAD SIZE.870-UNC-2B.870-14UNF-2B 1.0000-8UNC-2B 1.0000-12UNF-2B 1404 1424 1604 1624 1407 1427 1607 1627 THREAD SIZE 1.0-7UNC-2B 1.0-12UNF-2B 1.200-7UNC-2B 1.200-12UNF-2B STEEL CARBON, GRADE B, 1804 1824 2004 2024 1807 1827 2007 2027 THREAD SIZE 1.370-6UNC-2B 1.370-12UNF-2B 1.000-6UNC-2B 1.000-12UNF-2B 2204 2224 2404 2424 2207 2227 2407 2427
INACTIVE PART NUMBERS FOR NEW DESIGN THE FOLLOWING PART NUMBERS IN TABLE IV ARE INACTIVE FOR NEW DESIGN AFTER 21 MAR 166. USE FOR MAINTENANCE PURPOSES ONLY. TABLE IV - CONTINUED THREAD SIZE 1.700-UNC-2B 2.0000-4-1/4UNC-2B 2.200-4-1/2UNC-2B 2.000-4UNC-2B STEEL, CARBON,GRADE B, 2804 3204 3604 4004 2807 3207 3607 4007 THREAD SIZE 2.700-4UNC-2B 3.0000-4UNC-2B MATERIAL DASH NO DASH NO 4404 4804 4407 4807 INTERCHANGEABILITY TABLE OF AND PART NUMBERS FOR INTERCHANGEABILITY BETWEEN THE (GRADE A ) NUT AND THE (GRADED B ) NUTS, SEE TABLE V. TABLE IV PART NUMBERS PART NUMBERS PART NUMBERS PART NUMBERS MS31-401 421 01 MS31-404 424 04 MS31-801 821 01 MS31-804 824 04 MS31-1401 1421 1601 MS31-1404 1424 1604 MS31-2201 2221 2401 MS31-2204 2224 2404 21 601 621 24 604 624 21 1001 1021 24 1004 1024 1621 1801 1821 1624 1804 1824 2421 2801 3201 2424 2804 3204 701 721 704 724 1201 1221 1204 1224 2001 2021 2004 2024 3601 4001 4401 4801 3604 4004 4404 4804 10
INTERCHANGEABILITY TABLE OF 0R AND PART NUMBERS THE NUTS COVERED BY THE DASH NUMBERS GIVEN IN THE ORIGINAL ISSUE OF THIS STANDARD ARE OR 1/ AFTER 21 MAR 166. THE NUTS SHOULD BE USED FOR MAINTENANCE PURPOSE UNTIL EXISTING STOCK IS DEPLETED. USE ONLY THE NUTS FOR DESIGN. TABLE VI PART NUMBERS PART NUMBERS PART NUMBERS PART NUMBERS OR OR OR OR MS31-401 402 403 MS31-1 1 1 MS31-60 1/ 607 608 MS31-17 18 18 MS31-821 822 823 MS31-37 37 37 MS31-1028 102 1030 MS31-4 4 1/ 404 40 1/ 407 1 1 2 60 610 611 18 1 20 1/ 824 82 1/ 827 37 37 38 1031 1201 1202 6 7 7 408 40 0 2 2 3 612 621 622 20 21 21 828 82 830 38 38 3 1203 1/ 1204 120 7 7 7 1 2 421 4 4 623 1/ 624 62 21 21 21 831 01 02 40 1/ 1207 1208 120 8 8 8 422 423 1/ 424 1/ 627 628 62 22 22 22 03 1/ 04 0 1210 1211 1221 60 61 42 1/ 427 428 6 6 630 631 632 23 24 24 06 1/ 07 08 42 42 1222 1223 1/ 1224 61 61 61 42 430 431 6 7 8 701 702 703 2 2 2 0 10 11 42 43 44 122 1/ 1227 1228 61 62 62 432 01 02 8 1/ 704 70 1/ 707 2 2 26 21 22 23 122 1230 1231 62 63 64 03 1/ 04 0 708 70 710 26 26 27 1/ 24 2 26 1401 1402 1403 1/ 07 08 0 10 10 10 711 721 722 28 2 2 1/ 27 28 2 46 46 46 1/ 1404 140 1406 10 11 12 11 12 12 723 1/ 724 72 2 2 2 0 1 1001 47 48 4 1/ 1407 1408 140 66 66 66 21 22 23 1/ 727 728 72 30 30 30 1002 1003 1/ 1004 4 4 4 10 11 1421 67 68 1/ 24 2 1/ 27 14 730 731 801 31 32 33 100 1/ 1007 1008 4 0 0 1422 1423 1/ 1424 28 2 30 14 14 1 802 803 1/ 804 33 33 33 100 0 1 0 1 2 142 1426 1/ 1427 70 31 32 601 16 16 17 80 1/ 807 808 33 34 34 1021 1022 1023 3 3 3 1428 142 1430 70 70 71 602 603 1/ 604 17 17 17 80 0 1 34 3 36 1/ 1024 102 1/ 1027 3 3 4 1431 1601 1602 72 73 73 11
INTERCHANGEABILITY TABLE OF 0R AND PART NUMBERS THE NUTS COVERED BY THE DASH NUMBERS GIVEN IN THE ORIGINAL ISSUE OF THIS STANDARD ARE OR 1/ AFTER 21 MAR 166. THE NUTS SHOULD BE USED FOR MAINTENANCE PURPOSE UNTIL EXISTING STOCK IS DEPLETED. USE ONLY THE NUTS FOR DESIGN. TABLE VI - CONTINUED. PART NUMBERS PART NUMBERS PART NUMBERS PART NUMBERS OR OR OR OR MS31-1603 1/ 1604 160 MS31-73 73 73 1/ MS31-2004 200 2006 MS31-8 8 8 MS31-240 2406 1/ 2407 MS31-10 10 106 MS31-3606 3607 3608 MS31-121 122 122 1606 1/ 1607 1608 73 74 74 1/ 2007 2008 200 0 0 0 2408 240 20 106 106 107 360 3610 3611 122 123 124 160 1610 1611 74 7 76 2010 2011 2021 1 2 21 2421 2422 108 4001 4002 4003 1621 1622 1623 2022 2023 1/ 2024 2423 1/ 2424 242 1/ 4004 400 4006 1/ 1624 162 1626 202 2026 1/ 2027 4 2426 1/ 2427 2428 110 110 1/ 4007 4008 400 126 126 126 1/ 1627 1628 162 78 78 78 2028 202 2030 4 4 242 2430 2431 110 111 112 4010 4011 4401 127 128 1630 1631 1801 7 80 2031 2201 2202 6 2801 2802 2803 4402 4403 1/ 4404 1802 1803 1/ 1804 2203 1/ 2204 220 1/ 2804 280 2806 440 4406 1/ 4407 0 180 1806 1/ 1807 82 2206 1/ 2207 2208 8 8 1/ 2807 2808 280 114 114 114 4408 440 40 0 0 1 1808 180 10 82 82 83 220 2210 2211 8 100 20 21 3201 11 116 41 4801 4802 2 11 1821 1822 84 2221 2222 2223 3202 3203 1/ 3204 4803 1/ 4804 480 1823 1/ 1824 182 1/ 2224 222 2226 320 3206 1/ 3207 118 4806 1/ 4807 4808 4 4 1826 1/ 1827 1828 86 86 1/ 2227 2228 222 102 102 102 3208 320 3210 118 118 11 480 40 4 6 182 1830 1831 86 87 88 2230 2231 2401 103 104 10 3211 3601 3602 120 121 121 2001 2002 2003 8 8 8 2402 2403 1/ 2404 10 10 10 3603 1/ 3604 360 121 121 121 12
INTERCHANGEABILITY TABLE OF AND PART NUMBERS THE FOLLOWING NUTS COVERED BY DASH NUMBERS GIVEN IN MS16203 (SHIPS) ARE AFTER THE DATE INDICATED ON THE DOCUMENT. USE THE DASH NUMBERS GIVEN IN TABLE II. THE NUTS CANNOT ALWAYS REPLACE THE NEW NUTS AND SHOULD BE USED UNTIL EXISISTING STOCKS ARE DEPLETED. USE ONLY THE NEW NUTS FOR NEW DESIGN AND REPLACEMENT. REPLACEMENT SHALL BE IN ACCORDANCE WITH TABLES VI AND VII. INTERCHANGEABILITY INFORMATION REGARDING PART NUMBERS ON THE SUPERSEDED DRAWING IS ALSO CONTAINED IN THIS TABLE. TABLE VII DASH NUMBERS DASH NUMBERS DASH NUMBERS MS16203 (SHIPS) SUPERSEDED BY MS31 MS16203 (SHIPS) SUPERSEDED BY MS31 MS16203 (SHIPS) SUPERSEDED BY MS31 - -14-1 -16-3 -11-1 -27-17 -18-1 -20-3 -1 - -67-21 -22-23 -24-7 -83-1 -107 Custodians: Air Force Preparing activity: DLA-IS (Project 310-2722) NOTE: The activities listed above were interested in this document as of the date of this document. Since organizations and responsibilities can change, you should verify the currency of the information above using the ASSIST Online database at mailto:http://assist.daps.dla.mil/