Superalloy Bolt Torque Chart

These torque values are calculated using a target preload of 65% of the room-temperature yield strength for each grade, with K-factors of 0.20 (dry, as machined) and 0.14 (lubricated with MoS2 or nickel-based anti-seize). Values are for coarse-pitch metric threads per ISO 898-1 methodology adapted for nickel alloy fasteners.

Important: These are general engineering recommendations, not a substitute for joint-specific analysis. For critical joints, always verify torque by testing on the actual joint assembly with the specified lubricant. At elevated temperature, preload relaxation may require higher initial torque or live-load tensioning. Contact our engineering team for joint-specific calculations.

Size	Inconel 718		A-286		Nimonic 80A		C-276		Monel K-500		Inconel 625
Size	Dry	Lubed	Dry	Lubed	Dry	Lubed	Dry	Lubed	Dry	Lubed	Dry	Lubed
M6	8.5	6.0	7.0	5.0	8.0	5.8	5.5	4.0	7.5	5.5	6.5	4.8
M8	20	14	17	12	19	14	13	9.5	18	13	15	11
M10	40	28	33	23	37	27	26	18	35	25	30	22
M12	70	49	58	40	66	47	45	32	62	44	53	38
M16	175	122	145	100	165	116	110	78	155	110	130	93
M20	340	238	280	195	320	228	215	150	300	215	255	182
M24	590	413	490	340	560	395	375	262	525	372	445	315
M30	1170	819	970	680	1110	780	740	520	1040	735	880	625
M36	2050	1435	1700	1190	1950	1365	1300	910	1820	1285	1540	1095
M42	3300	2310	2750	1920	3150	2200	2100	1470	2940	2070	2490	1765
M48	4960	3470	4100	2870	4720	3300	3150	2200	4400	3100	3730	2640
M56	7950	5565	6600	4620	7580	5300	5050	3535	7060	4970	5980	4230
M64	11700	8190	9700	6790	11150	7800	7400	5180	10380	7310	8790	6230
M72	16700	11690	13900	9730	15950	11150	10600	7420	14850	10450	12580	8910
M80	23000	16100	19100	13370	21950	15350	14600	10220	20400	14380	17300	12260
M90	33000	23100	27400	19180	31500	22000	21000	14700	29300	20600	24800	17580
M100	45500	31850	37800	26460	43400	30380	28900	20230	40400	28420	34200	24240

Lubrication Notes

Recommended lubricant: MoS2 dry film or nickel-based anti-seize (Never-Seize Nickel Special or equivalent).
Do NOT use: Copper-based or graphite-based anti-seize on nickel alloys. Copper causes liquid-metal embrittlement above 400°C.
Assembly temperature: For joints assembled at elevated temperature, tighten to the “dry” column regardless of lubricant, then verify hot with tension measurement.
Re-torque: After the first thermal cycle, re-torque to 90% of the initial value to compensate for embedment relaxation. Do not exceed the initial torque.

Assumptions & Limitations

K-factor: 0.20 dry, 0.14 lubricated. Actual K-factor varies with thread finish, plating, and lubricant batch. Test 5-10 samples per lot for critical joints.
Target preload: 65% of room-temperature yield strength. For gasketed joints or fatigue-critical applications, the preload target may differ.
Thread class: ISO 6g/6H. Fine-pitch threads (not shown) require approximately 10-15% lower torque for the same preload.
Temperature effect: At temperatures above 300°C, preload may relax by 10-30% depending on grade, time, and temperature. See our Temperature-Strength Curves page for grade-specific relaxation data.
Disclaimer: These values are advisory. Always validate on your specific joint geometry, material stack-up, and assembly procedure.

For bolts larger than M100 or non-standard thread forms: Contact our engineering team for a joint-specific torque calculation. Provide bolt diameter, thread pitch, material grade, lubrication condition, and joint type (hard joint, soft gasket, or tension-controlled).

Lubrication Notes

Assumptions & Limitations

Related Technical Resources

Bolt Selection Guide

Temperature-Strength Curves

Engineering FAQ

Need custom high temp bolts? Let's talk.