Drilled Hole Tolerances per MIL-HDBK-727 Design Guidance for Producibilty

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Tolerance Charts Menu

Drilling is an operation performed by a rotary end cutting tool with one or more cutting edges and usually one or more flutes for the passage of chips and cutting fluid. Holes drilled by this process are limited by the available drill sizes. The table below provides the tolerances of the holes produced by some of these drills. These tolerances are often adequate without further machining operations, such as reaming or boring. Here location also can add significantly to production cost. As shown in Fig. 2, the tolerance on hole locations can affect the process, which in turn has significant cost effects. Deep hole drilling is also a factor affecting cost. Fig. 1 shows how cost increases as the ratio of length to diameter goes beyond 3 to 1.

Related: Machinist Drilled Hole Tolerance Capabilities Chart per. AND10387

Drill
Size
Tolerance
Plus
Minus
mm
(in.)
mm
(in.)
mm
(in.)
80
0.343
(0.0135)
0.058
(0.0023)
0.013
(0.0005)
79
0.368
(0.0145)
0.061
(0.0024)
0.013
(0.0005)
1 /64
0.396
(0.0156)
0.064
(0.0025)
0.013
(0.0005)
78
0.406
(0.016)
0.064
(0.0025)
0.013
(0.0005)
77
0.457
(0.018)
0.066
(0.0026)
0.013
(0.0005)
76
0.508
(0.020)
0.069
(0.0027)
0.013
(0.0005)
75
0.533
(0.02 1)
0.069
(0.0027)
0.013
(0.0005)
74
0.572
(0.0225)
0.071
(0.0028)
0.013
(0.0005)
73
0.610
(0.024)
0.071
(0.0028)
0.013
(0.0005)
72
0.635
(0.025)
0.074
(0.0029)
0.013
(0.0005)
71
0.660
(0.026)
0.074
(0.0029)
0.013
(0.0005)
70
0.711
(0.028)
0.076
(0.003)
0.013
(0.0005)
69
0.742
(0.0292)
0.076
(0.003)
0.013
(0.0005)
68
0.787
(0.031)
0.079
(0.0031)
0.013
(0.0005)
1/32
0,794
(0.0312)
0.079
(0.0031)
0.013
(0.0005)
67
0.813
(0.032)
0.079
(0.0031)
0.013
(0.0005)
66
0.838
(0.033)
0.081
(0.0032)
0.013
(0.0005)
65
0.889
(0.035)
0.081
(0.0032)
0.013
(0.0005)
64
0.914
(0.036)
0.084
(0.0033)
0.013
(0.0005)
63
0.940
(0.037)
0.084
(0.0033)
0.013
(0.0005)
62
0.965
(0.038)
0.084
(0.0033)
0.013
(0.0005)
61
0.991
(0.039)
0.084
(0.0033)
0.013
(0.0005)
60
1.016
(0.040)
0.086
(0.0034)
0.013
(0.0005)
59
1.041
(0.041)
0.086
(0.0034)
0.025
(0.001)
58
1.067
(0.042)
0.086
(0.0034)
0.025
(0.001)
57
1.092
(0.043)
0.089
(0.0035)
0.025
(0.001)
56
1.181
(0.0465)
0.089
(0.0035)
0.025
(0.001)
3/64
1.191
(0.0469)
0.091
(0.0036)
0.025
(0.001)
55
1.321
(0.052)
0.094
(0.0037)
0.025
(0.001)
54
1.397
(0.055)
0.097
(0.0038)
0.025
(0.001)
53
1.511
(0.0595)
0.099
(0.0039)
0.025
(0.001)
1/16
1.588
(0.0625)
0.099
(0.0039)
0.025
(0.001)
52
1.613
(0.0635)
0.099
(0.0039)
0.025
(0.001)
51
1.702
(0.067)
0.102
(0.004)
0.025
(0.001)
50
1.778
(0.070)
0.104
(0.0041)
0.025
(0.001)
49
1.854
(0.073)
0.104
(0.0041)
0.025
(0.001)
48
1.930
(0.076)
0.107
(0.0042)
0.025
(0.001)
5/64
1.984
(0.0781)
0.107
(0.0042)
0.025
(0.001)
47
1.994
(0.0785)
0.107
(0.0042)
0.025
(0.001)
46
2.057
(0.081)
0.109
(0.0043)
0.025
(0.001)

 

Drill
Size
Tolerance
Plus
Minus
mm
(in.)
mm
(in.)
mm
(in.)
45
2.083
(0.082)
0.109
(0.0043)
0.025
(0.001)
44
2.184
(0.086)
0.112
(0.0044)
0.025
(0.001)
43
2.261
(0.089)
0.112
(0.0044)
0.025
(0.001 )
42
2.375
(0.0935)
0.114
(0.0045)
0.025
(0.001
3/32
2.381
(0.0938)
0.114
(0.0045)
0.025
(0.001
41
2.438
(0.096)
0.114
(0.0045)
0.025
(0.001
40
2.488
(0.098)
0.117
(0.0046)
0.025
(0.001
39
2.527
(0.0995)
0.117
(0.0046)
0.025
(0.001
38
2.578
(0.1015)
0.117
(0.0046)
0.025
(0.001
37
2.642
(0.104)
0.119
(0.0047)
0.025
(0.001)
36
2.705
(0.1065)
0.119
(0.0047)
0,025
(0.001)
7/64
2.779
(0.1094)
0.119
(0.0047)
0.025
(0.001)
35
2.794
(0.110)
0.119
(0.0047)
0.025
(0.001)
34
2.819
(0.111)
0.122
(0.0048)
0.025
(0.001)
33
2.870
(0.113)
0.122
(0.0048)
0.025
(0.001)
32
2.946
(0.116)
0.122
(0.0048)
0.025
(0.001)
31
3.048
(0.120)
0.124
(0.0049)
0.025
(0.001 )
1 /’8
3.175
(0.125)
0.127
(0.005)
0.025
(0.001)
30
3.264
(0.1285)
0.127
(0.005)
0.025
(0.001)
29
3.454
(0.136)
0.130
(0.0051)
0.025
(0.001)
28
3.569
(0.1405)
0.132
(0.0052)
0.025
(0.001)
9/64
3.572
(0.1406)
0.132
(0.0052)
0.025
(0.001)
27
3.658
(0.144)
0.132
(0.0052)
0.025
(0.001)
26
3.734
(0.147)
0.132
(0.0052)
0.025
(0.001)
25
3.797
(0.1495)
0.135
(0.0053)
0.025
(0.001)
24
3.861
(0.152)
0.135
(0.0053)
0.025
(0.001)
23
3.912
(0.154)
0.135
(0.0053)
0.025
(0.001)
5/32
3.969
(0.1562)
0.135
(0.0053)
0.025
(0.001)
22
3.988
(0.157)
0.135
(0.0053)
0.025
(0.001)
21
4.039
(0.159)
0.137
(0.0054)
0.025
(0.001)
20
4.089
(0.161)
0.137
(0.0054)
0.025
(0.001)
19
4.216
(0.166)
0.140
(0.0055)
0.025
(0.001)
18
4.305
(0.1695)
0.140
(0.0055)
0.025
(0.001)
11/64
4,366
(0.1719)
0.140
(0.0055)
0.025
(0.001)
17
4.394
(0.173)
0.140
(0.0055)
0.025
(0.001)
16
4.496
(0.177)
0.142
(0.0056)
0.025
(0.001)
15
4.572
(0.180)
0.142
(0.0056)
0.025
(0.001)
14
4.623
(0.182)
0.142
(0.0056)
0.025
(0.001)
13
4.699
(0.185)
0.145
(0.0057)
0.025
(0.001)
3/16
4.762
(0.1875)
0.145
(0.0057)
0.025
(0.001)

 

Drill
Size
Tolerance
Plus
Minus
mm
(in.)
mm
(in.)
mm
(in.)
12
4.801
(0.189)
0.145
(0.0057)
0.025
(0.001)
11
4.851
(0.191)
0.145
(0.0057)
0.025
(0.001)
10
4.915
(o.1935)
0.145
(0.0057)
0.025
(0.001)
9
4.978
(0.196)
0.147
(0.0058)
0.025
(0.001)
8
5.055
(0.199)
0.147
(0.0058)
0.025
(0.001)
7
5.105
(0.201)
0.147
(0.0058)
0.025
(0.001)
13/64
5.159
(0.2031)
0.147
(0.0058)
0.025
(0.001)
6
5.182
(0.204)
0.147
(0.0058)
0.025
(0.001)
5
5.220
(0.2055)
0.150
(0.0059)
0.025
(0.001)
4
5.309
(0.209)
0.150
(0.0059)
0.025
(0.001)
3
5.410
(0.213)
0.150
(0.0059)
0.025
(0.001)
7/32
5.556
(0.2188)
0.152
(0.006)
0.025
(0.001)
2
5.613
(0.221)
0.152
(0.006)
0.025
(0.001)
1
5.791
(0.228)
0.155
(0.0061)
0.025
(0.001)
A
5.944
(0.234)
0.155
(0.0061)
0.025
(0.001)
15/64
5.953
(0.2344)
0.155
(0.0061)
0.025
(0.001)
B
6.045
(0.238)
0.155
(0.0061)
0.025
(0.001)
c
6.147
(0.242)
0.157
(0.0062)
0.025
(0.001)
D
6.248
(0.246)
0.157
(0.0062)
0.025
(0.001)
1/4
6.350
(0.250)
0.160
(0.0063)
0.025
(0.001)
F
6.528
(0.257)
0.160
(0.0063)
0.025
(0.001)
G
6.629
(0.261)
0.160
(0.0063)
0.025
(0.001)
17/64
6.747
(0.2656)
0.163
(0.0064)
0.025
(0.001)
H
6.756
(0.266)
0.163
(0.0064)
0.025
(0.001)
I
6.909
(0.272)
0.163
(0.0064)
0.025
(0,001)
J
7.036
(0,277)
0.165
(00065)
0.051
(0.002)
K
7.137
(0.281)
0.165
(0.0065)
0.051
(0.002)
9/32
7.144
(0.2812)
0.165
(0.0065)
0.051
(0.002)
L
7.366
(0.290)
0.168
(0.0066)
0.051
(0.002)
M
7.493
(0.295)
0.168
(0.0066)
0.051
(0.002)
19/64
7.541
(0.2969)
0.168
(0.0066)
0.051
(0.002)
N
7.671
(0.302)
0.170
(0.0067)
0.051
(0.002)
5/16
7.938
(0.3125)
0.170
(0.0067)
0.051
(0.002)
o
8.026
(0.316)
0.173
(0.0068)
0.051
(0.002)
P
8.204
(0.323)
0.173
(0.0068)
0.051
(0.002)
21/64
8.334
(0.3281)
0.173
(0.0068)
0.051
(0.002)
Q
8.433
(0.332)
0.175
(0.0069)
0.051
(0.002)
R
8.611
(0.339)
0.175
(0.0069)
0.051
(0.002)
11/32
8.731
(0.3438)
0.178
(0.007)
0.051
(0.002)
s
8.839
(0.348)
0.178
(0.007)
0.051
(0.002)

 

Drill
Size
Tolerance
Plus
Minus
mm
(in.)
mm
(in. )
mm
(in.)
T
9.093
(0.358)
0.180
(0.0071)
0.051
(0.002)
23/64
9.128
(0.3594)
0.180
(0.0071)
0.051
(0.002)
u
9.347
(0.368)
0.183
(0.0072)
0.051
(0.002)
3/8
9.525
(0.375)
0.183
(0.0072)
0.051
(0.002)
v
9.576
(0.377)
0.183
(0.0072)
0.051
(0.002)
w
9.804
(0.386)
0.183
(0.0072)
0.051
(0.002)
25/64
9.922
(0.3906)
0.185
(0.0073)
0.051
(0.002)
x
10.084
(0.397)
0.185
(0.0073)
0.051
(0.002)
Y
10.262
(0.404)
0.185
(0.0073)
0.051
(0.002)
13/32
10.319
(0.4062)
0.188
(0.0074)
0.051
(0.002)
z
10.490
(0.413)
0.188
(0.0074)
0.051
(0.002)
27/64
10.716
(0.4219)
0,190
(0.0075)
0.051
(0.002)
7/16
11.112
(0.4375)
0.190
(0.0075)
0.051
(0.002)
29/64
11.509
(0.4531)
0.193
(0.0076)
0.051
(0.002)
15/32
11.906
(0.4688)
0.196
(0.0077)
0.051
(0.002)
31/64
12.303
(0.4844)
0.198
(0.0078)
0.051
(0.002)
1/2
12.700
(0.500)
0.201
(0.0079)
0.051
(0.002)
33/64
13.097
(0.5156)
0.203
(0.008)
0.051
(0.002)
17/32
13.494
(0.5312)
0.206
(0.0081)
0.051
(0.002)
35/64
13.891
(0.5469)
0.206
(0.0081)
0.051
(0.002)
9/16
14.288
(0.5625)
0.208
(0.0082)
0.051
(0.002)
37/64
14.684
(0.5781)
0.211
(0.0083)
0.051
(0.002)
19/32
15.081
(0.59375)
0.213
(0.0084)
0.051
(0.002)
43/64
15.478
(0.6094)
0.213
(0.0084)
0.051
(0.002)
5/8
15.875
(0.625)
0.216
(0.0085)
0.051
(0.002)
41/64
16.272
(0.6406)
0.218
(0.0086)
0.051
(0.002)
21/32
16.669
(0.65625)
0.218
(0.0086)
0.051
(0.002)
43/64
17.066
(0.6719)
0.221
(0.0087)
0.051
(0.002)
11/16
17.462
(0.6875)
0.224
(0.0088)
0.051
(0.002)
45/64
17.859
(0.7031)
0.224
(0.0088)
0.051
(0.002)
23/32
18.256
(0.7188)
0.226
(0.0089)
0.051
(0.002)
47/64
18.653
(0.7344)
0.229
(0.009)
0.051
(0.002)
3/4
19.050
(0.750)
0.229
(0.009)
0.051
(0.002)
49/64
19.447
(0.7656)
0.231
(0.0091)
0.076
(0.003)
25/32
19.844
(0.7812)
0.234
(0.0092)
0.076
(0.003)
51/64
20.241
(0.7969)
0,234
(0.0092)
0.076
(0.003)
13/16
20.638
(0.8125)
0.236
(0.0093)
0.076
(0.003)
53/64
21.034
(0.8281)
0.236
(0.0093)
0.076
(0.003)
27/32
21.431
(0.8438)
0.239
(0.0094)
0.076
(0.003)
55/64
21.828
(0.8594)
0.241
(0.0095)
0.076
(0.003)

 

Drill
Size
Tolerance
Plus
Minus
mm
(in. )
mm
(in.)
mm
(in.)
7/8
22.228
(0.8751)
0.241
(0.0095)
0.076
(0.003)
57/64
22.622
(0.8906)
0.244
(0.0096)
0.076
(0.003)
29/32
23.019
(0.9062)
0.244
(0.0096)
0.076
(0.003)
59/64
23.416
(0.9219)
0.246
(0.0097)
0.076
(0.003)
15/16
23.813
(0.9375)
0.246
(0.0097)
0.076
(0.003)
61/64
24.209
(0.9531)
0.249
(0.0098)
0.076
(0.003)
31 /32
24.606
(0.9688)
0.249
(0.0098)
0.076
(0.003)
1
25.400
(1.000)
0.254
(0.010)
0.076
(0.003)

Length Expressed as Ratio of Diameter L/D
Figure 1 Length Expressed as Ratio of Diameter L/D

Cost Comparison of Drilled Holes as Affected by Depth

Figure 2 Cost Comparison of Drilled Holes as Affected by Depth

Source

  • MIL-HDBK-727 - Design for Producibility Handbook
    Department of Defense
    Army Materials and Mechanics Research Center

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