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