Torque Chart for A 307 Bolts & Studs

Bolt Size	TPI	Proof	Clamp	Tightening Torque (ft lbs)
		Proof Load (lbs)	Clamp Load (lbs)	Galv+Waxed	Galv	Plain
1⁄4	20	1145	859	2	4	4
5⁄16	18	1886	1415	4	9	7
3⁄8	16	2790	2093	7	16	13
7⁄16	14	3827	2870	10	26	21
1⁄2	13	5108	3831	16	40	32
9⁄16	12	6552	4914	23	58	46
5⁄8	11	8136	6102	32	79	64
3⁄4	10	12024	9018	56	141	113
7⁄8	9	15200	11400	83	208	166
1	8	20000	15000	125	313	250
11⁄8	7	25200	18900	177	443	354
11⁄4	7	32000	24000	250	625	500
13⁄8	6	38100	28575	327	819	655
11⁄2	6	46400	34800	435	1088	870
13⁄4	5	68400	51300	748	1870	1496
2	41⁄2	90000	67500	1125	2813	2250
21⁄4	41⁄2	117000	87750	1645	4113	3291
21⁄2	4	144000	108000	2250	5625	4500
23⁄4	4	177480	133110	3050	7626	6101
3	4	214920	161190	4030	10074	8060
31⁄4	4	255600	191700	5192	12980	10384
31⁄2	4	299880	224910	6560	16400	13120
33⁄4	4	347760	260820	8151	20377	16301
4	4	398880	299160	9972	24930	19944

Bolt Size	TPI	Tension		Tightening Torque Range
				Galv.	Plain
		Min	Max	Min – Max	Min Max
1⁄2	13	12000	14000	50 – 58	100 – 117
5⁄8	11	19000	23000	99 – 120	198 – 240
3⁄4	10	28000	34000	175 – 213	350 – 425
7⁄8	9	39000	47000	284 – 343	569 – 685
1	8	51000	61000	425 – 508	850 – 1017
11⁄8	7	56000	67000	525 – 625	1050 – 1256
11⁄4	7	71000	85000	740 – 885	1479 – 1771
13⁄8	6	85000	102000	974 – 1169	1948 – 2338
11⁄2	6	103000	124000	1288 – 1550	2575 – 3100

Bolt Size	TPI	Proof Load (lbs)	Clamp Load (lbs)	Tightening Torque (ft lbs)
				Galv.	Plain
1⁄4	20	3,350	2,513	13	10
5⁄16	18	5,500	4,125	27	21
3⁄8	16	8,150	6,113	48	38
7⁄16	14	11,150	8,363	76	61
1⁄2	13	14,900	11,175	116	93
9⁄16	12	19,100	14,325	168	134
5⁄8	11	23,750	17,813	232	186
3⁄4	10	35,050	26,288	411	329
7⁄8	9	48,500	36,375	663	530
1	8	63,650	47,738	995	796
11⁄8	7	80,100	60,075	1,408	1,126
8	82,934	62,201	583	1,166
11⁄4	7	101,750	76,313	1,987	1,590
8	105,006	78,754	820	1,641
13⁄8	6	121,300	90,975	2,606	2,085
8	129,492	97,119	1,113	2,226
11⁄2	6	147,550	110,663	3,458	2,767
8	156,687	117,515	1,469	2,938
13⁄4	5	199,500	149,625	–	4,364
8	218,400	163,800	–	4,778
2	41⁄2	262,500	196,875	–	6,563
8	290,850	218,138	–	7,271
21⁄4	41⁄2	341,250	255,938	–	9,598
8	373,801	280,351	–	10,513
21⁄2	4	420,000	315,000	–	13,125
8	466,200	349,650	–	14,569
23⁄4	4	468,500	351,263	–	16,100
8	515,851	386,888	–	17,732
3	4	567,150	425,363	–	21,268
8	618,451	463,838	–	23,192
31⁄4	4	674,500	505,875	–	27,402
8	730,550	547,913	–	29,679
31⁄2	4	791,350	593,513	–	34,622
8	851,201	638,401	–	37,240
33⁄4	4	917700	688275	–	43017
8	982,300	736,725	–	46,045
4	4	1052600	789450	–	52630
8	1,121,950	841,463	–	56,098

Torque Chart