ASME B18.16.6 Nylon Insert Lock Nuts

ASME B18.16.6 Nylon Insert Lock Nuts

Dimensions of Nylon Insert Lock Nuts

Nominal Size, A Width Across Flats, B Minimum Width Across Corners, C Height, D Minimum Hex Height, E Minimum Bearing Surface Diameter, F Maximum Total Runout of Bearing Surface, FIM
Max Min Max Min
1/4 0.439 0.430 0.488 0.328 0.298 0.225 0.416 0.010
5/16 0.502 0.489 0.557 0.359 0.329 0.250 0.475 0.011
3/8 0.564 0.551 0.628 0.468 0.438 0.335 0.534 0.012
7/16 0.627 0.616 0.698 0.468 0.438 0.324 0.597 0.013
1/2 0.752 0.736 0.840 0.609 0.579 0.464 0.712 0.014
9/16 0.877 0.861 0.982 0.656 0.626 0.469 0.830 0.015
5/8 0.940 0.922 1.051 0.765 0.735 0.593 0.890 0.016
3/4 1.064 1.052 1.191 0.890 0.860 0.742 1.033 0.018
7/8 1.252 1.239 1.403 0.999 0.969 0.790 1.230 0.020
1 1.440 1.427 1.619 1.078 1.016 0.825 1.418 0.022
1 1/8 1.627 1.614 1.833 1.203 1.141 0.930 1.605 0.025
1 1/4 1.815 1.801 2.046 1.422 1.360 1.125 1.793 0.028
1 3/8 2.008 1.973 2.259 1.609 1.547 1.282 1.962 0.031
1 1/2 2.197 2.159 2.473 1.640 1.578 1.313 2.148 0.034

Proof Loads, Clamp Loads and Prevailing-Torques for Coarse Thread Series Grades NE2, NE5, and NE8 Nuts

Nut Size and Thread per inch. Grade NE2 Grade NE5 Grade NE8 Prevailing-Torque
Proof Load, lb Clamp Load, lb Proof Load, lb Clamp Load, lb Proof Load, lb Clamp Load, lb Maximum First Install, in. lb Minimum First Removal, in. lb Minimum Fifth Removal, in. lb
1/4 - 20 2900 1300 3800 2000 4750 2850 40 5.0 1.5
5/18 - 18 4700 2150 6300 3350 7850 4700 80 8.0 2.5
3/8 - 16 7000 3200 9300 4950 11,600 6950 110 12.0 4.0
7/16 - 14 9550 4400 12,800 6800 15,900 9600 135 17.0 5.0
1/2 - 13 12,800 5850 17,000 9050 21,300 12,800 204 22.0 7.5
9/16 - 12 16,400 7550 21,800 11,600 27,300 16,400 300 30.0 10.0
5/8 - 11 20,300 9300 27,200 14,500 33,900 20,300 420 39.0 12.5
3/4 - 10 30,000 13800 40,100 21,300 50,100 30,100 540 58.0 20.0
7/8 - 9 41,600 12400 55,400 29,500 69,300 41,600 840 88.0 30.0
1 - 8 54,500 15000 72,700 38,700 90,900 54,600 1080 120.0 40.0
1 1/8 - 7 68,700 18900 80,100 42,100 115,000 69,000 1200 150.0 50.0
1 1/4 - 7 87,200 24000 101,700 53,500 145,000 87,000 1320 188.0 60.0
1 3/8 - 6 104,000 28700 121,300 63,800 173,000 104,000 1620 220.0 70.0
1 1/2 - 6 126,000 34800 147,500 77,600 211,000 127,000 1800 260.0 90.0

Proof Loads, Clamp Loads and Prevailing-Torques for Fine Thread Series Grades NE2, NE5, and NE8 Nuts

Nut Size and Thread per inch. Grade NE2 Grade NE5 Grade NE8 Prevailing-Torque
Proof Load, lb Clamp Load, lb Proof Load, lb Clamp Load, lb Proof Load, lb Clamp Load, lb Maximum First Install, in. lb Minimum First Removal, in. lb Minimum Fifth Removal, in. lb
1/4 - 28 3300 1500 4350 2300 5450 3250 40 5.0 1.5
5/16 - 24 5200 2400 4950 3700 8700 5200 60 8.0 2.5
3/8 - 24 7900 3600 10500 5600 13200 7900 110 12.0 4.0
7/16 - 20 10,700 4900 14200 7550 17800 10700 135 17.0 5.0
1/2 - 20 14,400 6550 19200 10200 24000 14400 204 22.0 7.5
9/16 - 18 18,300 8350 24400 13000 30400 18300 300 30.0 10.0
5/8 - 18 22,900 10500 30700 16300 38400 23000 420 39.0 12.5
3/4 - 16 33,600 15400 44800 23800 56000 33600 540 58.0 20.0
7/8 - 14 45,800 12600 61100 32400 76400 45800 840 88.0 30.0
1 - 14 61,100 16800 81500 43300 101900 61100 1080 120.0 40.0
1 - 12 59,700 16400 79600 42300 99500 59700 1080 120.0 40.0
1 1/8 - 12 76,900 21200 89900 47500 128000 76800 1200 150.0 50.0
1 1/4 - 12 96,600 26600 113000 59700 161000 96600 1320 188.0 60.0
1 3/8 - 12 118,000 32500 138000 72900 197000 118000 1620 220.0 70.0
1 1/2 - 12 142,000 39100 166000 87700 237000 142000 1800 260.0 90.0

Chemical Composition Requirements

Nut Grade C, Max Mn, Min. P, Max. S, Max.
NE2 0.47 ... 0.12 0.15
NE5 0.55 0.30 0.05 0.15
NE8 0.55 0.30 0.04 0.05

Hardness Requirements

Nut Grade Locknut Size Rockwell Hardness
NE2, NE5 1/4 - 1 1/2 C28, max.
NE8 1/4 - 5/8 C24 - C32
  3/4 - 1 C26 - C34
  1 1/8 - 1 1/2 C26 - C36