Root Analysis - Bolted Joint Design Specialists

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Essential reference data for bolted joint design, including torque values, material properties, and engineering standards.

Typical Bolt Torques (Nut Factor Method)

	Grade 8.8				Grade 10.9				Grade 12.9
	dry k=0.2		lubricated k=0.15		dry k=0.2		lubricated k=0.15		dry k=0.2		lubricated k=0.15
	Nm	Lb.ft	Nm	Lb.ft	Nm	Lb.ft	Nm	Lb.ft	Nm	Lb.ft	Nm	Lb.ft
M8	26.4	19.5	19.8	14.6	28.5	21	21.4	15.8	36.5	27.9	27.3	20
M10	52.2	38.5	39.2	28.9	56.6	41.8	42.4	31.2	72.2	53	54.2	40
M12	91	67.1	68	50.2	99	73	74	58	126	93	94	70.8
M14	145	107	109	80.4	157	116	118	87	200	147.5	150	111
M16	226	167	170	125	245	181	184	135	313	231	235	173
M20	441	325	331	244	478	353	358	264	610	450	458	338
M24	762	562	572	422	826	609	620	457	1055	778	791	583
M30	1515	1117	1136	838	1641	1210	1231	908	2095	1545	1572	1159
M36	2647	1952	1985	1464	2868	2115	2151	1587	3662	2701	2746	2025

Note: Torque values based on SAE J1701M standard. k represents the nut factor used in torque calculations. Values are for guidance only and should be verified for specific applications.

Typical Bolt Torques (VDI 2230 Method)

	Grade 8.8				Grade 10.9				Grade 12.9
	dry μ=0.2		lubricated μ=0.12		dry μ=0.2		lubricated μ=0.12		dry μ=0.2		lubricated μ=0.12
	Nm	Lb.ft	Nm	Lb.ft	Nm	Lb.ft	Nm	Lb.ft	Nm	Lb.ft	Nm	Lb.ft
M4	4.1	3	3	2.2	6	4.4	4.6	3.4	7	5.2	5.1	3.8
M5	8.1	6	5.9	4.4	11.9	8.8	8.6	6.3	14	10.3	10	7.4
M6	14	10	10	7	21	15	15	11	24	18	17	13
M8	34.3	25	25	18	50	37	36	27	59	43	42	31
M10	68	50	48	35	100	74	71	52	116	86	83	61
M12	117	86	84	62	172	127	123	91	201	148	144	106
M16	291	215	206	152	428	316	302	223	501	370	354	261
M20	588	434	415	306	838	618	592	437	980	723	692	510
M24	1011	746	714	527	1440	1062	1017	750	1685	1243	1190	878
M27	1498	1105	1050	774	2134	1574	1496	1103	2497	1842	1750	1291
M30	2031	1498	1428	1053	2893	2134	2033	1500	3386	2498	2380	1755

Note: Torque values based on VDI 2230 method. μ represents friction coefficient. Values are for guidance only and should be verified for specific applications.

Guideline Thread Engagement Lengths

Grade	Mild and high strength steel		Aluminium		Cast Iron
Grade	350 MPa	> 450 MPa	150 MPa	> 275 MPa	175 MPa	> 300 MPa
8.8	0.75D	0.5D	2D	1D	1D	0.5D
10.9	1D	0.75D	3D	1.5D	1.5D	0.75D
12.9	1.5D	1D	3.5D	2D	1.75D	1D

Note: Thread engagement lengths are expressed as multiples of the nominal diameter (D). Values are for guidance only and should be verified for specific applications.

Guideline Material Properties

Material	Elastic Modulus (GPa)	Maximum Allowable Surface Pressure (MPa)	Shear Strength Ratio
Mild Steel	205	250–400	0.6
High-Strength Steel	205	400–700	0.6
Aluminium	70	50–150	0.6
Brass	105	80–120	0.75
Copper	120	60–100	0.7
Cast Iron*	80–150	150–450	0.9–1.3
Engineering Plastics	3.2	10–40	0.85
Stainless Steel	193	250–450	0.6
Titanium Alloys	110	300–500	0.6

Note: *Cast iron has large ranges depending on structure and grade. Check carefully your application.

Guideline Material Corrosion Combinations

Corrosion compatibility guidelines for different material combinations will be added here.

		Female Thread
		Uncoated Steel	Zinc-Plated Steel	Nickel-Plated Steel	Stainless Steel	Aluminium	Cast Iron	Titanium	Copper	Brass
Male Thread	Uncoated Steel
	Zinc-Plated Steel
	Nickel-Plated Steel
	Stainless Steel
	Aluminium
	Cast Iron
	Titanium
	Copper
	Brass

Green: Allowable (low risk)

Yellow: Caution (moderate risk)

Red: Not allowable (high risk)

Note: This table shows galvanic corrosion risk between different material combinations for male and female threads. Use with caution and verify for specific applications.

Useful Standards for Threaded Fasteners

	British	German	American	Indian	International
	BSI	DIN	ASME	IS	ISO
	British Standards Institute	Deutsches Institut für Normung	American Society of Mechanical Engineers	Bureau of Indian Standards	International Standards Organization
Basic Form	BS 1580 (inch series) BS 3643 (metric series)	N/A	ANSI B1	IS4218	ISO 68
Detailed Dimensions		DIN 13		IS4218	ISO 261
Tolerances		DIN 13		IS14962	ISO 965
Mechanical Properties	BS 20898	DIN 267	SA-307, SA-325	IS 1367	ISO 898

Note: This table shows key standards for different aspects of threaded fastener design across major international standards bodies.