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SAE J995 Nuts Specification

SAE J995 Scope

SAE J995 Standard covers the mechanical and material requirements for three grades of steel nuts suitable for use in automotive and related engineering applications, in sizes 1/4 to 1-1/2 in, inclusive, and with dimensions conforming with the requirements ASME B18.2.2 or ASME B18.6.3 respectively. SAE J995 defines 3 grades if nuts grade 2,5 & 8.

Related Specifications of SAE J995 Bolting

SAE J429 ISO 898-1 ISO 898-2 A193 F2281

SAE J995 Chemical composition

Nut Grade C Max Mn Min P Max S Max
2 0.55 - 0.1 2 (2) 0.1 5 (3)
5 0.55 0.3 0.05 (4)(5) 0.15(3)(5)
8 0.55 0.3 0.04 0.05 (6)
  • All values are forladle analys is (percent by weight) and subject to standard variations for check analys is as given in SAE j409.
  • Resulfurized and rephosphorized material is not subject to reject ion based on check analys is for sulfur.
  • If agreed between purchaser and producer, sulfur content may be 0.23 maximum.
  • Phosphorus content may be 0.1 3 m aximum for acid bessemer steel only.
  • If agreed between purchaser and producer, sulfur content may be 0.35 maximum and phosphorus content may be 0.1 2 maximum provided that manganese content is 0.70 minimum.
  • If agreed between purchaser and producer, sulfur content may be 0.33 maximum provided that manganese content is 1.35 minimum .

SAE J995 Mechanical Requirements

Proof load requirements for nuts(1)

Nut Grade 2 5 8
Nut Size 1/4 thru 1-1/2 1/4 thru 1-1/2 1/4 thru 1 1/4 thru 1 Over 1 thru 1-1/2 Over 1 thru 1-1/2 1/4 thru 1-1/2 1/4 thru 1-1/2
Thread Series UNC and 8UN UNF , 1 2 UN and F iner UNC and 8UN UNF , 1 2 UN and F iner UNC and 8UN UNF , 12UN and Finer UNC and 8UN UNF, 1 2UN and Finer
Nut Type Proof Load Stress , psi(1 ) Proof Load Stress , psi(1 ) Proof Load Stress , psi(1 ) Proof Load Stress , psi(1 ) Proof Load Stress , psi(1 ) Proof Load Stress , psi(1 ) Proof Load Stress , psi(1 ) Proof Load Stress , psi(1 )
Hex 90000 80000 120000 109000 105000 94000 150000 150000
Hex Flange 90000 80000 120000 109000 105000 94000 150000 150000
Hex Jam(2) 54000 48000 72000 65000 63000 57000 90000 90000
Heavy Hex Jam(2) 54000 48000 72000 65000 63000 57000 90000 90000
Hex Slotted(2) 71000 65000 96000 87000 84000 75000 120000 120000
Heavy Hex(2) 100000 90000 133000 120000 116000 105000 165000 150000
Hex Thick(2) 100000 90000 133000 120000 116000 105000 165000 150000
Hex Thick Slotted(2) 79000 71000 105000 96000 92000 84000 132000 120000
Hex High(2) 100000 90000 133000 120000 116000 105000 165000 150000
Hex High Slotted(2) 79000 71000 105000 96000 92000 84000 132000 120000
Square 90000 80000 105000 96000 92000 84000 132000 120000
Heavy Square 100000 90000 133000 120000 116000 105000 165000 150000
  • The proof load in pounds for nutsis computed by multip lying the proof load stress , in psi ( lbf/in2) , for the nut g rade, size , th read series , and type , as shownin Tab le 2 , and tensile stress area in square inches ( in2) , for the app l icab le size and th read series shownin Tab le 3.(For tabulated values see Appendix A. )
    To convert the inch based pounds per square inch (psi ) values above to metric Megapascal (MPa) units , multip ly the above values by.00689 .
  • Proof load stress values for hex jam , heavy hex jam , hex slotted , heavy hex, hex thick, heavy hex slotted , and hex thick slotted nuts are based on the requiremen t for hex nuts.primarily, each value is derived from the ratio of the minim um thickness of the productinvo lved tothe minimum thickness of similar hex or square machine screw nuts and hex nuts (see B1 8.2.2 ) of the same size .

Tensile stress areas (test bolt or mandrel)

Coarse Thread
Series UNC
Nominal Size
and Threads
Per Inch		 Coarse Thread Series UNC Tensile Stress Area, sq in. Fine Thread Series UNF Normal Size and Threads Per Inch Fine Thread Series UNF Tensile Stress Area, sq in. 8-Thread Series 8 UN Normal Size and Threads Per Inch 8-Thread Series 8 UN Tensile Stress Area, sq in.
1/4- 20 0.0318 1/4- 28 0.0364 - -
1/4- 20 0.0318 1/4- 28 0.0364 - -
5/16- 18 0.0524 5/16- 24 0.0580 - -
3/8- 16 0.0775 3/8- 24 0.0878 - -
7/16- 14 0.1063 7/16- 20 0.1187 - -
1/2- 13 0.1419 1/2- 20 0.1599 - -
9/16- 12 0.182 9/16- 18 0.203 - -
5/8- 11 0.226 5/8- 18 0.256 - -
3/4- 10 0.334 3/4- 16 0.373 - -
7/8- 9 0.462 7/8- 14 0.509 - -
1-8 0.606 1- 12 0.663 1-1/8 0.606
1-1/8- 7 0.763 1-1/8- 12 0.856 1-1/8-8 0.790
1-1/4- 7 0.969 1-1/4- 12 1.073 1-1/4-8 1.000
1-3/8- 6 1.155 1-3/8- 12 1.315 1-3/8-8 1.233
1-1/2- 6 1.405 1-1/2- 12 1.581 1-1/2-8 1.492

Hardness requirements for nuts

Nut Grade Nominal Nut Size Hardness
2 1/4 thru 1-1/2 32 HRC max
5 1/4 thru 1-1/2 32 HRC max
8 1/4 thru 5/8 24- 32 HRC
8 Over 5/8 thru 1 26- 32 HRC
8 Over 1 thru 1-1/2 26- 32 HRC

Proof load for miscellaneous nuts, (1) LBF (unc threads only)

Nominal Nut Size and Threads Per Inch Hex and Hex Flange Nuts Hex Jam and Heavy Hex Jam Nuts Hex Slotted Nuts
Grade 2 Grade 5 Grade 8 Grade 2 Grade 5 Grade 8 Grade 2 Grade 5 Grade 8
1/4- 20 2850 3800 4750 1750 2300 2850 2250 3050 3800
5/1 6- 18 4700 6300 7850 2800 3750 4700 3700 5050 6300
3/8- 16 7000 9300 11600 4200 5600 7000 5500 7450 9300
7/1 6- 14 9550 12800 15900 5750 7650 9550 7550 10200 12800
1/2- 13 12800 17000 21300 7650 10200 12800 10100 13600 17000
9/1 6- 12 16400 21800 27300 9850 13100 16400 12900 17500 21800
5/8- 11 20300 27100 33900 12250 16300 20300 16050 21700 27100
3/4- 10 30100 40100 50100 18000 24000 30100 23700 32100 40100
7/8- 9 41600 55400 69300 25000 33300 41600 32800 44400 55400
1- 8 54500 72700 90900 32700 43600 54500 43050 58200 72700
1-1/8- 7 68700 80100 114000 41200 48100 68700 54200 64100 91600
1-1/4- 7 87200 102000 145000 52350 61000 87200 68800 81400 116000
1-3/8- 6 104000 121000 173000 62350 72800 104000 82000 97000 139000
1-1/2- 6 126000 148000 211000 75850 88500 126000 99750 118000 169000
Nominal Nut Size and
Threads Per Inch		 Heavy Hex, Hex Thick, Hex High and Heavy Square Nuts Heavy Hex Slotted, Hex High
Slotted and Hex Thick Slotted Nuts		 Square Nuts
Grade 2 Grade 5 Grade 8 Grade 2 Grade 5 Grade 8 Grade 2 Grade 5 Grade 8
1/4- 20 3200 4250 5250 2500 3350 4200 2850 3350 4200
5/1 6- 18 5200 6950 8650 4150 5500 6900 4700 5500 6900
3/8- 16 7750 10300 12800 8100 8150 10200 7000 8150 10200
7/1 6- 14 10600 14100 17500 8400 11200 14000 9550 11200 14000
1/2- 13 14200 18900 23400 11200 14900 18700 12800 14900 18700
9/1 6- 12 18150 24200 30000 14350 19100 24000 16400 19100 24000
5/8- 11 22600 30100 37300 17800 23700 29800 20300 23700 29800
3/4- 10 33300 44400 55100 26350 35100 44100 30100 35100 44100
7/8- 9 46050 61400 76200 36400 48500 61000 41600 48500 61000
1- 8 60450 80600 100000 47700 63600 80000 54500 63600 80000
1-1/8- 7 76300 88500 126000 60300 70200 101000 68700 70200 101000
1-1/4- 7 96900 112000 160000 76550 89100 128000 87200 89100 128000
1-3/8- 6 115500 134000 191000 91250 106000 152000 104000 106000 152000
1-1/2- 6 140500 163000 232000 111000 129000 185000 126000 129000 185000
  • Values computed by multiplying the strength values (psi) by the tensiles tress area (in2) . The values are rounded to the closest 50-pound increment.
  • To convert the inch based pounds values above to metric based Newtons (N) multiple the values above by 4. 448.

Proof load for miscellaneous nuts, (1) LBF (unf threads only)

Nominal Nut Size and Threads Per Inch Hex and Hex Flange Nuts Hex Jam and Heavy Hex Jam Nuts Hex Slotted Nuts
Grade 2 Grade 5 Grade 8 Grade 2 Grade 5 Grade 8 Grade 2 Grade 5 Grade 8
1/4- 28 2900 4000 5460 1750 2400 3300 2400 3200 4350
5/1 6- 24 4650 6300 8700 2800 3750 5200 3750 5050 6950
3/8- 24 7000 9550 13150 4200 5700 7900 5700 7650 10550
7/1 6- 20 9500 13000 17800 5700 7700 10700 7700 10350 14250
1/2- 20 12800 17450 24000 6700 10400 14400 10400 13900 19200
9/1 6-18 16250 22150 30450 9750 13200 18250 13200 17650 24350
5/8-18 20500 27900 38400 12300 16650 23000 16650 22250 30700
3/4- 1 6 29850 40650 55950 17900 24250 33550 24250 32450 44750
7/8- 1 4 40700 55500 76350 24450 33100 45800 33100 44300 61100
1-12 53050 72300 99450 31800 43100 59650 43100 57700 79600
1-1/8-12 68500 80450 128400 41100 48800 77050 55650 64200 102700
1-1/4-12 85850 100850 160950 51500 61150 96550 69750 80500 128750
1-3/8-12 105200 123800 197250 63100 74950 118350 85500 98600 157800
1-1/2-12 126500 148600 237150 75900 90100 142300 102750 118600 189700
Nominal Nut Size and
Threads Per Inch		 Heavy Hex, Hex Thick, Hex High and Heavy Square Nuts Heavy Hex Slotted, Hex High
Slotted and Hex Thick Slotted Nuts		 Square Nuts
Grade 2 Grade 5 Grade 8 Grade 2 Grade 5 Grade 8 Grade 2 Grade 5 Grade 8
1/4- 28 3300 4400 5460 2600 3500 4350 2900 3500 4350
5/1 6- 24 5200 7000 8700 4100 5550 6950 4650 5550 6950
3/8- 24 7900 10550 13170 6250 8450 10550 7000 8450 10550
7/1 6- 20 10700 14250 17805 8450 11400 14250 9500 11400 14250
1/2- 20 14400 19200 23985 11350 15350 19200 12800 15350 19200
9/1 6-18 18250 24350 30450 14400 19500 24350 16250 19500 24350
5/8-18 23000 30700 38400 18200 24600 30700 20500 24600 30700
3/4- 1 6 33550 44750 55950 26500 35800 44750 29850 35800 44750
7/8- 1 4 45800 61100 76350 36150 48850 61100 40700 48850 61100
1-12 59650 79550 99450 47100 36650 79550 53050 36650 79550
1-1/8-12 77050 89900 128400 60800 71900 102700 68500 71900 102700
1-1/4-12 96550 112650 160950 76200 90150 128750 85850 90150 128750
1-3/8-12 118350 138100 197250 93350 110450 157800 105200 110450 157800
1-1/2-12 142300 166000 237150 112250 132800 189700 126500 132800 189700
  • Values computed by multiplying the strength values (psi) by the tensile stress area ( in2) . The values are rounded to the closest 50-pound increment.

Proof load for miscellaneous nuts, (1) LBF (un 8 threads only)

Nominal Nut Size and Threads Per Inch Hex and Hex Flange Nuts Hex Jam and Heavy Hex Jam Nuts Hex Slotted Nuts
Grade 2 Grade 5 Grade 8 Grade 2 Grade 5 Grade 8 Grade 2 Grade 5 Grade 8
1-8 54550 72700 90900 32700 43650 54550 39400 58200 72700
1-1 /8-8 71100 83000 118500 42650 49750 71100 51350 66350 94800
1-1 /4-8 90000 105000 150000 54000 63000 90000 65000 84000 120000
1-3/8-8 110950 129450 184950 66600 77700 110950 80150 103550 147950
1-1 /2-8 134300 156650 223800 80550 94000 134300 97000 125350 179050
Nominal Nut Size and Threads Per Inch Heavy Hex, Hex Thick, Hex High and Heavy Square Nuts Heavy Hex Slotted, Hex High Slotted and Hex Thick Slotted Nuts Square Nuts
Grade 2 Grade 5 Grade 8 Grade 2 Grade 5 Grade 8 Grade 2 Grade 5 Grade 8
1-8 60600 80600 100000 47850 63650 80000 54550 63650 80000
1-1 /8-8 79000 91650 130350 62400 72700 104300 71100 72700 104300
1-1 /4-8 100000 116000 165000 79000 92000 132000 90000 92000 132000
1-3/8-8 123300 143050 203450 97400 113450 162750 110950 113450 162750
1-1 /2-8 149200 173050 246200 117850 137250 197000 134300 137250 197000
  • Values computed by multiplying the strength values (psi) by the tensile stress area ( in2 ) . The values are rounded to the closest 50-pound increment.

SAE J995 Bolting Surface Treatment Specifications

SAE J995 Testing Standards

ASME Threading Specifications

F606/F606M Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets
F1470 Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection