Angle Tolerances For Iso 2768 Metal General tolerance ISO 2768 does not specify where to use these tolerance. As per design requirement and manufacturing capability tolerance class is defined. General Tolerance - Iso 2768-mh (din 7168) (jis B 0419) Table 1. P ermissible d eviations for line ar dimensions ex cept chamfere d parts. (externa l radii and chamf er heights, s ee Table 2.) relevant basic dimens ion (s). P ermissible d eviations for line ar dimensions of c hamfered parts. Be indicated ad jacent to the relevant bas.

• Angle Tolerances For Iso 2768 Metals
• Iso 2768 Mh Tolerance Chart
• Iso 2768 Mh Tolerances
• Iso 2768-m Tolerances
• Angle Tolerances For Iso 2768 Mk

• Angular Dimension
• External Radius and Chamfer height
• Geometric Tolerance such as straightness, flatness, perpendicularity, symmetry and runout.

General Tolerance : ISO 2768

Linear DimensionsNominal Length Range in mmTolerance Classf
(fine)m
(Medium)c
(coarse)v
(very coarse)0.5 up to 3±0.05±0.1±0.2-3 up to 6±0.05±0.1±0.3±0.53 up to 30±0.1±0.2±0.5±130 up to 120±0.15±0.3±0.8±1.5120 up to 400±0.2±0.5±1.2±2.5400 up to 1000±0.3±0.8±2.0±4.01000 up to 2000±0.5±1.2±3.0±6.02000 up to 4000-±2.0±4.0±8.0

Angle Tolerances For Iso 2768 Metals

External Radius and Chamfer HeightsNominal Length Range in mmTolerance Classf
(fine)m
(Medium)c
(coarse)v
(very coarse)0.5 up to 3±0.2±0.2±0.4±0.4over 3 up to 6±0.5±0.5±1.0±1.0over 6±1.0±1.0±2.0±2.0Angular DimensionsNominal Length Range in mmTolerance Classf
(fine)m
(Medium)c
(coarse)v
(very coarse)up to 10±1°±1°±1°30'±3°over 10 up to 50±0°30'±0°30'±1°±2°over 50 up to 120±0°20'±0°20'±0°30'±1°over 120 up to 400±0°10'±0°10'±0°15'±0°30'over 400±0°50'±0°50'±0°10'±0°20'Straightness and FlatnessNominal Length Range in mmTolerance ClassHKLup to 100.020.050.1over 10 up to 300.050.10.2over 30 up to 1000.10.20.4over 100 up to 3000.20.40.8over 300 up to 10000.30.61.2over 1000 up to 30000.40.81.6PerpendicularityNominal Length Range in mmTolerance ClassHKLup to 1000.20.40.6over 100 up to 3000.30.61over 300 up to 10000.40.81.5over 1000 up to 30000.50.82SymmetryNominal Length Range in mmTolerance ClassHKLup to 1000.50.60.6over 100 up to 3000.50.61over 300 up to 10000.50.81.5over 1000 up to 30000.512RunoutHKL0.10.20.5

Read this article for details on Limit Fit and Tolerance.

The information below can be used to calculate the values of thread tolerances defined by ISO 965/1.

Tolerances are written as a combination of a tolerance band, signified by an alphabetic letter (E, G, e, f, g or h, with uppercase letters signifying internal threads, and lowercase signifying external), and a tolerance class, signified by a number. Grade 6 signifies general use, with smaller numbers being used for stricter tolerance, and higher numbers being used for more loose tolerances.

For instance, a 5G tolerance would signify a tolerance that is in the 5th tolerance class of band G.

Screw threads are usually signified by two tolerances, one for the maximum outside diameter measure from the major diameter of the thread, and one for the pitch diameter, measured from the midpoint of each tooth. For more information on measuring pitch diameter, see our article on how to measure a screw.

As an example, a common screw thread tolerance is 5g6g, which has a 5g tolerance on its pitch diameter, and a 6g tolerance on its external diameter.

Screws threads with identical external tolerances and pitch tolerances are expressed with a single tolerance letter and number. For instance, a screw with a 6g major diameter tolerance and a 6g pitch diameter tolerance would simply be written as “6g”.

The reason that the values for tolerance bands (signified by letters, found in table 1) are written as positive and negative numbers, and the values for tolerance classes (written as numbers, found in tables 2 - 5) are not, is because tolerance classes are applied interchangeably to both internal and external threads, and must be either subtracted or added to a tolerance, dependent on whether the thread is internal or external.

Iso 2768 Mh Tolerance Chart

Important Formulae
D	Major Diameter
D1	Minor Diameter Internal Thread
D2	Pitch Diameter Internal Thread
d	Major Diameter External Thread
d1	Minor Diameter External Thread
d2	Pitch Diameter External Thread
T	Tolerance
TD1	Tolerance for D1
TD2	Tolerance for D2
Td1	Tolerance for d1
Td2	Tolerance for d2
EI	Lower Deviation Internal Thread
ES	Upper Deviation Internal Thread
ei	Lower Deviation External Thread
es	Upper Deviation Internal Thread

Important Calculations
Internal Threads
Min major dia.	basic major dia. + EI (Table 1)
Max minor dia.	min minor dia. + TD1 (Table 2)
Max pitch dia.	min pitch dia. + TD2 (Table 4)
External Threads
Max major dia.	basic major dia. − es (Table 1)
Min major dia.	max major dia. − Td (Table 3)
Min pitch dia.	max pitch dia. − Td2 (Table 5)

Table 1: Fundamental Deviation Codes For Internal and External Metric Threads (EI/es)
Pitch	Allowance (Fundamental Deviation)
	External Thread				Internal Thread
	e	f	g	h	H	G
	es	es	es	es	EI	EI
0.2	N/A	N/A	-0.017	0	0	+0.017
0.25	N/A	N/A	-0.018	0	0	+0.018
0.3	N/A	N/A	-0.018	0	0	+0.018
0.35	N/A	-0.034	-0.019	0	0	+0.019
0.4	N/A	-0.034	-0.019	0	0	+0.019
0.45	N/A	-0.035	-0.020	0	0	+0.020
0.5	-0.050	-0.036	-0.020	0	0	+0.020
0.6	-0.053	-0.036	-0.021	0	0	+0.021
0.7	-0.056	-0.038	-0.022	0	0	+0.022
0.75	-0.056	-0.038	-0.022	0	0	+0.022
0.8	-0.060	-0.038	-0.024	0	0	+0.024
1	-0.060	-0.040	-0.026	0	0	+0.026
1.25	-0.063	-0.042	-0.028	0	0	+0.028
1.5	-0.067	-0.045	-0.032	0	0	+0.032
1.75	-0.071	-0.048	-0.034	0	0	+0.034
2	-0.071	-0.052	-0.038	0	0	+0.038
2.5	-0.080	-0.058	-0.042	0	0	+0.042
3	-0.085	-0.063	-0.048	0	0	+0.048
3.5	-0.090	-0.070	-0.053	0	0	+0.053
4	-0.095	-0.075	-0.060	0	0	+0.060
4.5	-0.100	-0.080	-0.063	0	0	+0.063
5	-0.106	-0.085	-0.071	0	0	+0.071
5.5	-0.112	-0.090	-0.075	0	0	+0.075
6	-0.118	-0.095	-0.080	0	0	+0.080

Iso 2768 Mh Tolerances

Table 2: Minor Diameter Tolerance of Internal Metric Threads (TD1)
Pitch	4	5	6	7	8
0.2	0.038	N/A	N/A	N/A	N/A
0.25	0.045	0.056	N/A	N/A	N/A
0.3	0.053	0.067	0.085	N/A	N/A
0.35	0.063	0.080	0.100	N/A	N/A
0.4	0.071	0.090	0.112	N/A	N/A
0.45	0.080	0.100	0.125	N/A	N/A
0.5	0.090	0.112	0.140	0.180	N/A
0.6	0.100	0.125	0.160	0.200	N/A
0.7	0.112	0.140	0.180	0.224	N/A
0.75	0.118	0.150	0.190	0.236	N/A
0.8	0.125	0.160	0.200	0.250	0.315
1	0.150	0.190	0.236	0.300	0.375
1.25	0.170	0.212	0.265	0.335	0.425
1.5	0.190	0.236	0.300	0.375	0.475
1.75	0.212	0.265	0.335	0.425	0.530
2	0.236	0.300	0.375	0.475	0.600
2.5	0.280	0.355	0.450	0.560	0.710
3	0.315	0.400	0.500	0.630	0.800
3.5	0.355	0.450	0.560	0.710	0.900
4	0.375	0.475	0.600	0.750	0.950
4.5	0.425	0.530	0.670	0.850	1.060
5	0.450	0.560	0.710	0.900	1.120
5.5	0.475	0.600	0.750	0.950	1.180
6	0.500	0.630	0.800	1.000	1.250

Table 3: Major Diameter Tolerance of External Metric Threads (Td)
Pitch	Tolerance Grade
	4	6	8
0.2	0.036	0.056	N/A
0.25	0.042	0.067	N/A
0.3	0.048	0.075	N/A
0.35	0.053	0.085	N/A
0.4	0.060	0.095	N/A
0.45	0.063	0.100	N/A
0.5	0.067	0.106	N/A
0.6	0.080	0.125	N/A
0.7	0.090	0.140	N/A
0.75	0.090	0.140	N/A
0.8	0.095	0.150	0.236
1	0.112	0.180	0.280
1.25	0.132	0.212	0.335
1.5	0.150	0.236	0.375
1.75	0.170	0.265	0.425
2	0.180	0.280	0.450
2.5	0.212	0.335	0.530
3	0.236	0.375	0.600
3.5	0.265	0.425	0.670
4	0.300	0.475	0.750
4.5	0.315	0.500	0.800
5	0.335	0.530	0.850
5.5	0.355	0.560	0.900
6	0.375	0.600	0.950

Iso 2768-m Tolerances

Table 4: Pitch Diameter Tolerance for Internal Metric Threads (TD2)
Basic Major Diameter		Pitch	Tolerance Grade
Over	Up to and Including		4	5	6	7	8
1.5	2.8	0.2	0.042	N/A	N/A	N/A	N/A
		0.25	0.048	0.060	N/A	N/A	N/A
		0.35	0.053	0.067	0.085	N/A	N/A
		0.4	0.056	0.071	0.090	N/A	N/A
		0.45	0.060	0.075	0.095	N/A	N/A
2.8	5.6	0.35	0.056	0.071	0.090	N/A	N/A
		0.5	0.063	0.080	0.100	0.125	N/A
		0.6	0.071	0.090	0.112	0.140	N/A
		0.7	0.075	0.095	0.118	0.150	N/A
		0.75	0.075	0.095	0.118	0.150	N/A
		0.8	0.080	0.100	0.125	0.160	0.200
5.6	11.2	0.75	0.085	0.106	0.132	0.170	N/A
		1	0.095	0.118	0.150	0.190	0.236
		1.25	0.100	0.125	0.160	0.200	0.250
		1.5	0.112	0.140	0.180	0.224	0.280
11.2	22.4	1	0.100	0.125	0.160	0.200	0.250
		1.25	0.112	0.140	0.180	0.224	0.280
		1.5	0.118	0.150	0.190	0.236	0.300
		1.75	0.125	0.160	0.200	0.250	0.315
		2	0.132	0.170	0.212	0.265	0.335
		2.5	0.140	0.180	0.224	0.280	0.355
22.4	45	1	0.106	0.132	0.170	0.212	N/A
		1.5	0.125	0.160	0.200	0.250	0.315
		2	0.140	0.180	0.224	0.280	0.355
		3	0.170	0.212	0.265	0.335	0.425
		3.5	0.180	0.224	0.280	0.355	0.450
		4	0.190	0.236	0.300	0.375	0.475
		4.5	0.200	0.250	0.315	0.400	0.500
45	90	1.5	0.132	0.170	0.212	0.265	0.335
		2	0.150	0.190	0.236	0.300	0.375
		3	0.180	0.224	0.280	0.355	0.450
		4	0.200	0.250	0.315	0.400	0.500
		5	0.212	0.265	0.335	0.425	0.530
		5.5	0.224	0.280	0.355	0.450	0.560
		6	0.236	0.300	0.375	0.475	0.600
90	180	2	0.160	0.200	0.250	0.315	0.400
		3	0.190	0.236	0.300	0.375	0.475
		4	0.212	0.265	0.335	0.425	0.530
		6	0.250	0.315	0.400	0.500	0.630
180	355	3	0.212	0.265	0.335	0.425	0.530
		4	0.236	0.300	0.375	0.475	0.600
		6	0.265	0.335	0.425	0.530	0.670

Angle Tolerances For Iso 2768 Mk

Table 5: Pitch Diameter Tolerance for External Metric Threads (Td2)
Basic Major Diameter		Pitch	Tolerance Grade
Over	Up to and Including		3	4	5	6	7	8	9
1.5	2.8	0.2	0.025	0.032	0.040	0.050	N/A	N/A	N/A
		0.25	0.028	0.036	0.045	0.056	N/A	N/A	N/A
		0.35	0.032	0.040	0.050	0.063	0.080	N/A	N/A
		0.4	0.034	0.042	0.053	0.067	0.085	N/A	N/A
		0.45	0.036	0.045	0.056	0.071	0.090	N/A	N/A
2.8	5.6	0.35	0.034	0.042	0.053	0.067	0.085	N/A	N/A
		0.5	0.038	0.048	0.060	0.075	0.095	N/A	N/A
		0.6	0.042	0.053	0.067	0.085	0.106	N/A	N/A
		0.7	0.045	0.056	0.071	0.090	0.112	N/A	N/A
		0.75	0.045	0.056	0.071	0.090	0.112	N/A	N/A
		0.8	0.048	0.060	0.075	0.095	0.118	0.150	0.190
5.6	11.2	0.75	0.050	0.063	0.080	0.100	0.125	N/A	N/A
		1	0.056	0.071	0.090	0.112	0.140	0.180	0.224
		1.25	0.060	0.075	0.095	0.118	0.150	0.190	0.236
		1.5	0.067	0.085	0.106	0.132	0.170	0.212	0.265
11.2	22.4	1	0.060	0.075	0.095	0.118	0.150	0.190	0.236
		1.25	0.067	0.085	0.106	0.132	0.170	0.212	0.265
		1.5	0.071	0.090	0.112	0.140	0.180	0.224	0.280
		1.75	0.075	0.095	0.118	0.150	0.190	0.236	0.300
		2	0.080	0.100	0.125	0.160	0.200	0.250	0.315
		2.5	0.085	0.106	0.132	0.170	0.212	0.265	0.335
22.4	45	1	0.063	0.080	0.100	0.125	0.160	0.200	0.250
		1.5	0.075	0.095	0.118	0.150	0.190	0.236	0.300
		2	0.085	0.106	0.132	0.170	0.212	0.265	0.335
		3	0.100	0.125	0.160	0.200	0.250	0.315	0.400
		3.5	0.106	0.132	0.170	0.212	0.265	0.335	0.425
		4	0.112	0.140	0.180	0.224	0.280	0.355	0.450
		4.5	0.118	0.150	0.190	0.236	0.300	0.375	0.475
45	90	1.5	0.080	0.100	0.125	0.160	0.200	0.250	0.315
		2	0.090	0.112	0.140	0.180	0.224	0.280	0.355
		3	0.106	0.132	0.170	0.212	0.265	0.335	0.425
		4	0.118	0.150	0.190	0.236	0.300	0.375	0.475
		5	0.125	0.160	0.200	0.250	0.315	0.400	0.500
		5.5	0.132	0.170	0.212	0.265	0.335	0.425	0.530
		6	0.140	0.180	0.224	0.280	0.355	0.450	0.560
90	180	2	0.095	0.118	0.150	0.190	0.236	0.300	0.375
		3	0.112	0.140	0.180	0.224	0.280	0.355	0.450
		4	0.125	0.160	0.200	0.250	0.315	0.400	0.500
		6	0.150	0.190	0.236	0.300	0.375	0.475	0.600
180	355	3	0.125	0.160	0.200	0.250	0.315	0.400	0.500
		4	0.140	0.180	0.224	0.280	0.355	0.450	0.560
		6	0.160	0.200	0.250	0.315	0.400	0.500	0.630