ASME B18.31.2 Continous Thread Studs

ASME B18.31.2 Continuous Thread Studs Standard covers the dimensional and general data for continuous thread studs recognized as American National Standard in inch dimensions.
Continuous thread stud: a stud that is threaded over its complete length and commonly used where adjustable nut positioning is required along the entire length of the stud.
The inclusion of dimensional data in ASME B18.31.2 Standard is not intended to imply that all products described are stock production items. Consumers should consult with suppliers concerning availability of products.

ASME B18.31.2 Dimensions for Continuous Thread Studs (mm)

Nominal Size	Diameter, D	Chamfered Thread Distance, U
		UNC Threads		UNF Threads		8UN Threads
		Min.	Max.	Min.	Max.	Min.	Max.
1/4	6.350	1.270	2.540	0.914	1.803	…	…
5/16	7.938	1.422	2.819	1.067	2.108	…	…
3/8	9.525	1.600	3.175	1.067	2.108	…	…
7/16	11.113	1.829	3.632	1.270	2.540	…	…
1/2	12.700	1.956	3.912	1.270	2.540	…	…
9/16	14.288	2.134	4.242	1.422	2.819	…	…
5/8	15.875	2.311	4.623	1.422	2.819	…	…
3/4	19.050	2.540	5.080	1.600	3.175	…	…
7/8	22.225	2.819	5.639	1.829	3.632	…	…
1	25.400	3.175	6.350	2.134	4.242	…	…
1 1/8	28.575	3.632	7.264	2.134	4.242	3.175	6.350
1 1/4	31.750	3.632	7.264	2.134	4.242	3.175	6.350
1 3/8	34.925	4.242	8.458	2.134	4.242	3.175	6.350
1 1/2	38.100	4.242	8.458	2.134	4.242	3.175	6.350
1 5/8	41.275	…	…	…	…	3.175	6.350
1 3/4	44.450	5.080	10.160	…	…	3.175	6.350
1 7/8	47.625	…	…	…	…	3.175	6.350
2	50.800	5.639	11.278	…	…	3.175	6.350
2 1/4	57.150	5.639	11.278	…	…	3.175	6.350
2 1/2	63.500	6.350	12.700	…	…	3.175	6.350
2 3/4	69.850	6.350	12.700	…	…	3.175	6.350
3	76.200	6.350	12.700	…	…	3.175	6.350
3 1/4	82.550	6.350	12.700	…	…	3.175	6.350
3 1/2	88.900	6.350	12.700	…	…	3.175	6.350
3 3/4	95.250	6.350	12.700	…	…	3.175	6.350
4	101.600	6.350	12.700	…	…	3.175	6.350

ASME B18.31.2 Continuous Thread Stud Length Tolerances (mm)

Range, LT	Tolerance
From 19.05 through 63.5	±1.016
Over 63.5 through 101.6	±2.032
Over 101.6 through 203.2	±2.540
Over 203.2 through 406.4	±3.048
Over 406.4	±4.572

ASME B18.31.2 Dimensions for Continuous Thread Studs (Inch)

Nominal Size	Diameter, D	Chamfered Thread Distance, U
		UNC Threads		UNF Threads		8UN Threads
		Min.	Max.	Min.	Max.	Min.	Max.
1/4	0.2500	0.050	0.100	0.036	0.071	…	…
5/16	0.3125	0.056	0.111	0.042	0.083	…	…
3/8	0.3750	0.063	0.125	0.042	0.083	…	…
7/16	0.4375	0.072	0.143	0.050	0.100	…	…
1/2	0.5000	0.077	0.154	0.050	0.100	…	…
9/16	0.5625	0.084	0.167	0.056	0.111	…	…
5/8	0.6250	0.091	0.182	0.056	0.111	…	…
3/4	0.7500	0.100	0.200	0.063	0.125	…	…
7/8	0.8750	0.111	0.222	0.072	0.143	…	…
1	1.0000	0.125	0.250	0.084	0.167	…	…
1 1/8	1.1250	0.143	0.286	0.084	0.167	0.125	0.250
1 1/4	1.2500	0.143	0.286	0.084	0.167	0.125	0.250
1 3/8	1.3750	0.167	0.333	0.084	0.167	0.125	0.250
1 1/2	1.5000	0.167	0.333	0.084	0.167	0.125	0.250
1 5/8	1.6250	…	…	…	…	0.125	0.250
1 3/4	1.7500	0.200	0.400	…	…	0.125	0.250
1 7/8	1.8750	…	…	…	…	0.125	0.250
2	2.0000	0.222	0.444	…	…	0.125	0.250
2 1/4	2.2500	0.222	0.444	…	…	0.125	0.250
2 1/2	2.5000	0.250	0.500	…	…	0.125	0.250
2 3/4	2.7500	0.250	0.500	…	…	0.125	0.250
3	3.0000	0.250	0.500	…	…	0.125	0.250
3 1/4	3.2500	0.250	0.500	…	…	0.125	0.250
3 1/2	3.5000	0.250	0.500	…	…	0.125	0.250
3 3/4	3.7500	0.250	0.500	…	…	0.125	0.250
4	4.0000	0.250	0.500	…	…	0.125	0.250

ASME B18.31.2 Continuous Thread Stud Length Tolerances (Inch)

Range, LT	Tolerances
From ¾ through 2½	±0.04
Over 2½ through 4	±0.08
Over 4 through 8	±0.10
Over 8 through 16	±0.12
Over 16	±0.18