ASME B18.16.6 Style NU Nylon Insert Locknut Dimensions

Designation		Width Across Flats, A		Minimum Width Across Corners, B	Thickness, C		Minimum Hex Height, D	Maximum Runout of Bearing Surface With Thread P.D. FIM
Size	Nominal Diameter	Max.	Min.	Minimum Width Across Corners, B	Max.	Min.	Minimum Hex Height, D	Maximum Runout of Bearing Surface With Thread P.D. FIM
¼	0.2500	0.506	0.489	0.556	0.390	0.360	0.290	0.010
5⁄16	0.3125	0.566	0.551	0.624	0.453	0.423	0.335	0.011
⅜	0.3750	0.691	0.675	0.763	0.562	0.532	0.392	0.012
7⁄16	0.4375	0.754	0.736	0.829	0.609	0.579	0.464	0.013
½	0.5000	0.879	0.861	0.969	0.718	0.688	0.544	0.014
9⁄16	0.5625	0.942	0.922	1.037	0.812	0.782	0.655	0.015
⅝	0.6250	1.067	1.045	1.175	0.874	0.844	0.677	0.016
¾	0.7500	1.255	1.231	1.382	1.015	0.985	0.790	0.018
⅞	0.8750	1.444	1.417	1.589	1.140	1.110	0.883	0.020
1	1.0000	1.632	1.602	1.796	1.312	1.250	1.000	0.022
1¹/₈	1.1250	1.820	1.788	2.002	1.469	1.407	1.096	0.025
1¼	1.2500	2.008	1.973	2.209	1.672	1.610	1.250	0.028
1⅜	1.3750	2.197	2.159	2.416	1.828	1.766	1.376	0.031
1½	1.5000	2.384	2.344	2.622	1.953	1.891	1.413	0.034
1⅝	1.6250	2.572	2.530	2.886	2.172	2.110	1.637	0.038
1¾	1.7500	2.762	2.715	3.035	2.376	2.250	1.830	0.041
1⅞	1.8750	2.950	2.901	3.242	2.422	2.296	1.875	0.044
2	2.0000	3.137	3.086	3.449	2.469	2.343	1.750	0.047
2¼	2.2500	3.514	3.457	3.862	2.876	2.750	2.063	0.052
2½	2.5000	4.015	3.875	4.618	3.204	3.078	2.475	0.058
2¾	2.7500	4.015	3.875	4.618	3.204	3.078	2.350	0.064
3	3.0000	4.640	4.500	5.102	3.704	3.578	2.750	0.070