Self Tapping Screws

Self tapping screws are a category of threaded fastener that form threads (tapping threads) as the screw is driven into a pre-drilled hole. Self tapping screws include thread cutting, thread rolling, and self drilling screws

Our self tapping screws can be customized to your application and industry. Please review and download our self tapping screw size charts below. 

Drive Screws Type U

Round Head

Nominal
Screw
Size
Number
Of Thread
Starts
D A H P Recommened
Hole Size
Outside
Diameter
Head
Diameter
Head
Height
Pilot
Diameter
Drill Size
No.
Hole
Diameter
Max. Min. Max. Min. Max. Min. Max. Min.
00
0
2
4
6
6
8
7
0.060
0.075
0.100
0.116
0.057
0.072
0.097
0.112
0.099
0.127
0.162
0.211
0.090
0.118
0.146
0.193
0.034
0.049
0.069
0.086
0.026
0.041
0.059
0.075
0.049
0.063
0.083
0.096
0.046
0.060
0.080
0.092
55
51
44
37
0.052
0.067
0.086
0.104
6
7
8
10
7
8
8
8
0.140
0.154
0.167
0.182
0.136
0.150
0.162
0.177
0.260
0.285
0.309
0.359
0.240
0.264
0.287
0.334
0.103
0.111
0.120
0.137
0.091
0.099
0.107
0.123
0.116
0.126
0.136
0.150
0.112
0.122
0.132
0.146
31
29
27
20
0.120
0.136
0.144
0.161
12
14
8
9
0.212
0.242
0.206
0.236
0.408
0.457
0.382
0.429
0.153
0.170
0.139
0.155
0.177
0.202
0.173
0.198
11
2
0.191
0.221
 
L Nominal
Screw Length
1/8 3/16 1/4 5/16 3/8 1/2 5/8 3/4 1 in. and
over
S Pilot Length 0.047 0.047 0.047 0.047 0.062 0.062 0.078 0.078 0.125

Flat Head 100º

Machine Screws

Nominal Size A H J T M G N Phillips
Driver Size
Head Diameter Height of Head Width of Slot Depth of Slot Dimensions of Recess
Diameter Depth Width
Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min.
2
4
5
6
7*
8
9*
10
12
14*
1/4
5/16
3/8
1/2
.172
.225
.252
.279
.305
.332
.358
.385
.438
.491
.507
.635
.762
.875
147
.195
.220
.244
.268
.292
.316
.340
.389
.437
.452
.568
.685
775
.051
.067
.075
.083
.091
.100
.108
.116
.132
.148
.153
.191
.230
.223
.040
.055
.062
.069
.076
.084
.091
.098
.112
.127
.131
.165
.200
.198
.031
.039
.043
.048
.048
.054
.054
.060
.067
.075
.075
.084
.094
.106
.023
.031
.035
.039
.039
.045
.045
.050
.056
.064
.064
.072
.081
.091
.023
.030
.034
.038
.041
.045
.049
.053
.060
.068
.070
.088
.106
.103
.015
.020
.022
.024
.027
.029
.032
.034
.039
.044
.046
.058
.070
.065
.102
.128
.154
.174
.182
.189
.258
.204
.268
.283
.283
.365
.393
.424
.089
.115
.141
.161
.169
.176
.245
.191
.255
.270
.270
.352
.380
.411
.063
.089
.086
.106
.114
.121
.146
.136
.156
.171
.171
.216
.245
.276
.017
.018
.027
.029
.030
.031
.034
.032
.036
.039
.035
.061
.065
.069
1
1
2
2
2
2
2
2-3*
3
3
3
4
4
4

Head Dimensions

Square Drive Flat Head

This type of recess has a squam center opening slightly tapered side walls and a conical bottom.

Nominal Size or Basic Screw Diameter M
Recess
Square
T
Recess
Depth
Drive
Size
F
Penetration
Gauging Depth
Max Min. Min. Max.   Max. Min.
3 0.0990
4 0.1120
5 0.1250
6 0.1380
7 0.1510
8 0.1640
10 0.1900
12 0.2160
1/4 0.2500
5/16 0.3125
3/8 0.3750
0.071
0.071
0.091
0.091
0.091
0.1126
0.1126
0.133
0.133
0.191
0.191
0.0696
0.0696
0.090
0.090
0.090
0.111
0.111
0.1315
0.1315
0.1895
0.1895
0.073
0.073
0.113
0.113
0.113
0.140
0.140
0.165
0.165
0.201
0.201
0.063
0.063
0.105
0.105
0.105
0.119
0.119
0.155
0.155
0.191
0.191
0
0
1
1
1
2
2
3
3
4
4
0.038
0.038
0.065
0.065
0.065
0.075
0.075
0.095
0.095
0.100
0.100
0.032
0.032
0.057
0.057
0.057
0.065
0.065
0.085
0.085
0.090
0.090

Hex Head

Hex Washer Head

Machine Screws
Tapping Screws
Self Drilling Screws

Nominal
Size
A W H F U J T
Width
Across
Flats
Width
Across
Corners
Height
of
Head
Diameter
of
Washer
Thickness
of
Washer
Width
of
Slot
Depth
of
Slot
Max. Min. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min.
4
6
7
8
10
12
14
1/4
5/16
3/8
.187
.250
.250
.250
.312
.312
.438
.375
.500
.562
.181
.244
.244
.244
.305
.305
.428
.367
.489
.551
.202
.272
.272
.272
.340
.340
.409
.409
.545
.614
.060
.093
.093
.110
.120
.155
.190
.190
.230
.295
.049
.080
.080
.096
.105
.139
.172
.172
.208
.270
.243
.328
.328
.348
.414
.432
.520
.520
.676
.780
.225
.302
.302
.322
.384
.398
.480
.480
.624
.720
.019
.025
.029
.031
.031
.039
.050
.050
.055
.063
.011
.015
.017
.019
.019
.022
.030
.030
.035
.037
.039
.048
.048
.054
.060
.067
.075
.075
.084
.094
.031
.039
.039
.045
.050
.056
.064
.064
.072
.081
.042
.053
.062
.074
.080
.103
.111
.111
.134
.168
.025
.033
.040
.052
.057
.077
.083
.083
100
.131

Oval Head

Machine Screws
Tapping Screws
Wood Screws*

Nominal
Size
A H O J T M G N Phillips
Driver
Size
Head Diameter Height of Head Width of Slot Depth of Slot Dimensions of Recess
Side Height Total Height Diameter Depth Width
Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min.
4
5*
6
8
9*
10
12
14*
1/4
.225
.252
.279
.332
.358
.385
.438
.491
.507
.195
.220
.244
.292
.316
.340
.389
.452
.452
.067
.075
.083
.100
.108
.116
.132
.148
.153
.054
.062
.069
.084
.091
.098
.112
.127
.131
.104
.116
.128
.152
.164
.176
.200
.224
.232
.084
.095
.105
.126
.137
.148
.169
.190
.197
.039
.043
.048
.054
.054
.060
.067
.075
.075
.031
.035
.039
.045
.045
.050
.056
.064
.064
.059
.067
.074
.088
.095
.103
.117
.132
.136
.049
.055
.060
.072
.078
.084
.096
.108
.112
.136
.158
.178
.192
.216
.209
.270
.305
.290
.123
.145
.165
.179
.203
.196
.257
.292
.277
.094
.085
.105
.119
.144
.137
.152
.188
.173
.019
.028
.030
.031
.034
.033
.038
.042
.040
1
2
2
2
2
2-3*
3
3
3

Pan Head

Machine Screws
Tapping Screws
Self Drilling Screws

Nominal
Size
A H H1 J T M G N Phillips
Driver
Size
Head Diameter Height of Head Width of Slot Depth of Slot Dimensions of Recess
Slotted Recessed Diameter Depth Width
Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min.
2
3
4
5
6
7

8
10
12
1/4
5/16
3/8
.167
.193
.219
.245
.270
.296
.322
.373
.425
.492
.615
.740
.155
.180
.205
.231
.256
.281
.306
.357
.407
.473
.594
.716
.053
.060
.068
.075
.082
.089
.096
.110
.125
.144
.178
.212
.045
.051
.058
.065
.072
.079
.085
.099
.112
.130
.162
.195
.062
.071
.080
.089
.097
.106
.115
.133
.151
.175
.218
.261
.053
.062
.070
.079
.087
.096
.105
.122
.139
.162
.203
.244
.031
.035
.039
.043
.048
.048
.054
.060
.067
.075
.084
.094
.023
.027
.031
.035
.039
.039
.045
.050
.056
.064
.072
.081
.031
.036
.040
.045
.050
.054
.058
.068
.077
.087
.106
.124
.022
.026
.030
.034
.037
.041
.045
.053
.061
.070
.085
.100
.104
.112
.122
.158
.166
.176
.182
.199
.259
.281
.350
.389
.091
.099
.109
.145
.153
.163
.169
.186
.246
.268
.337
.376
.059
.068
.078
.083
.091
.100
.108
.124
.141
.161
.193
.233
.017
.019
.019
.028
.028
.029
.030
.031
.034
.036
.169
.210
1
1
1
2
2
2
2
2
3
3
4
4

Head Dimensions

Combination Drive
Pan Head

  G H J A M T F N    
Screw
Size
Head
Dimensions
Slot
Dimemsions
Recess
Dimensions
Driver
Size
Head
Diam.
Head
Height
Width Depth Width Depth Max.
Rad
Min.
Wing
Width
Recess
Penetration
Max. Min. Max. Min. Max. Min.
0 .116
.104
.044
.036
.067
.054
.039
.021
.010 .013 .032 .014 0
1 .142
.130
.053
.044
.074
.061
.045
.025
.010 .014 .040 .022 0
2 .167
.155
.062
.053
.031 .023 .031 .022 .104
.091
.059
.041
.020 .017 .052 .034 1
3 .193
.180
.071
.062
.035 .027 .036 .026 .112
.099
.065
.050
.020 .019 .061 .043 1
4 .219
.205
.080
.070
.039 .031 .040 .030 .122
.109
.078
.060
.020 .019 .071 .053 1
5 .245
.231
.089
.079
.043 .035 .045 .034 .158
.145
.083
.057
.025 .028 .072 .046 2
6 .270
.256
.097
.087
.048 .039 .050 .037 .166
.153
.091
.066
.025 .028 .080 .055 2
7 .296
.281
.106
.096
.048 .039 .054 .041 .176
.163
.100
.075
.025 .029 .089 .064 2
8 .322
.306
.115
.105
.054 .045 .058 .045 .182
.169
.108
.082
.025 .030 .097 .071 2
10 .373
.357
.133
.122
.060 .050 .068 .053 .199
.186
.124
.100
.025 .031 .113 .089 2
12 .425
.407
.151
.139
.067 .056 .077 .061 .259
.246
.141
.115
.030 .034 .124 .098 3
1/4 .492
.473
.175
.162
.075 .064 .087 .070 .281
.268
.161
.135
.030 .036 .144 .118 3
5/16 .615
.594
.218
.203
.084 .072 .106 .085 .350
.337
.193
.169
.035 .059 .173 .149 4
3/8 .740
.716
.261
.244
.389
.376
.233
.210
.035 .065 .213 .190 4
7/16 .863
.838
.304
.286
.413
.400
.259
.234
.035 .068 .239 .214 4
1/2 .987
.958
.348
.327
.435
.422
.280
.255
.035 .071 .260 .235 4

Square Drive Pan Head

Self Tapping Screws

This type of recess has a square center opening, slightly tapered side walls and a conical bottom.

Nominal
Size or Basic Screw
Diameter
H R M T Driver
Size
P
Head
Height
Head
Radius
Recess
Square
Recess
Depth
Penetration
Gauging Depth
Max Min Min Max Min Max Min Max Min
3 0.0990
4 0.1120
5 0.1250
6 0.1380
0.078
0.086
0.095
0.103
0.067
0.075
0.083
0.091
0.010
0.010
0.015
0.015
0.071
0.071
0.091
0.091
0.0696
0.0696
0.090
0.090
0.073
0.073
0.113
0.113
0.063
0.063
0.105
0.105
0
0
1
1
0.038
0.038
0.065
0.065
0.032
0.032
0.057
0.057
7 0.1510
8 0.1640
10 0.1900
12 0.2160
0.111
0.120
0.137
0.153
0.099
0.107
0.123
0.139
0.015
0.015
0.020
0.025
0.091
0.112
0.112
0.133
0.090
0.111
0.111
0.1315
0.113
0.140
0.140
0.165
0.105
0.119
0.119
0.155
1
2
2
3
0.065
0.075
0.075
0.095
0.057
0.065
0.065
0.085
1/4 0.2500
5/16 0.3125
3/8 0.3750
0.175
0.216
0.256
0.160
0.198
0.237
0.035
0.040
0.040
0.133
0.191
0.191
0.1315
0.1895
0.1895
0.165
0.201
0.201
0.155
0.191
0.191
3
4
4
0.095
0.100
0.100
0.085
0.090
0.090

Pan Head

Torx®Drive

Screw
Size
Head Dimensions Recess Dimensions
D H R G (Fallaway)
Penetration
Head
Diameter
Head
Height
Ref. Gage
Penetration
Max. Min. Max. Min. Min. Max.
4
6
8
10
.219
.270
.322
.372
.205
.256
.306
.357
.080
.097
.115
.133
.070
.087
.105
.122
.111
.132
.155
.178
.035
.045
.055
.070
.016
.020
.025
.025

Truss Head

Machine Screws
Tapping Screws

Nominal
Size
A H J T M G N Phillips
Driver
Size
Head Diameter Height of Head Width of Slot Depth of Slot Dimensions of Recess
Diameter Depth Width
Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min.
4
6
8
10
1/4
5/16
3/8
.257
.321
.384
.448
.573
.698
.823
.241
.303
.364
.425
.546
.666
.787
.069
.086
102
.118
.150
.183
.215
.059
.074
.088
103
133
162
.191

.048
.054
.060
.075
.084
.094

.039
.045
.050
.064
.072
.081

.050
.058
.068
.087
.106
.124

.037
.045
.053
.070
.085
.100
.112
.158
.173
.188
.263
.352
.099
145
.160
.175
.250
.339
.069
.084
.099
.115
.143
.193
.017
.027
.029
.030
.033
.059
1
2
2
2
3
4

Threads and Points for Thread Cutting Screws and Self-Tapping Screws

Nominal Size or
Basic Screw Diameter
Threads
per
Inch
D P S L
Major
Diameter
Point
Diameter
Point Taper Length Determinant
Length for
Point Taper
Minimum Practical
Screw Length
For Short Screws For Long Screws
Max. Min. Max. Min. Max. Min. Max. Min. 90°
Heads
Csk Heads 90°
Heads
Csk Heads
2 0.0860
4 0.1120
6 0.1380
56
40
32
0.0860
0.1120
0.1380
0.0813
0.1061
0.1312
0.068
0.087
0.107
0.061
0.078
0.096
0.062
0.088
0.109
0.045
0.062
0.078
0.080
0.112
0.141
0.062
0.088
0.109
5/32
7/32
1/4
3/16
1/4
5/16
5/32
3/16
1/4
3/16
1/4
5/16
8 0.1640
10 0.1900
10 0.19000
32
24
32
0.1640
0.1900
0.1900
0.1571
0.1818
0.1831
0.132
0.148
0.158
0.122
0.135
0.148
0.109
0.146
0.109
0.078
0.104
0.078
0.141
0.188
0.141
0.109
0.146
0.109
1/4
11/32
1/4
11/32
7/16
11/32
1/4
5/16
1/4
5/16
13/32
5/16
12 0.2160
14 0.2500
5/16 0.3125
3/8 0.3750
24
20
18
16
0.2160
0.2500
0.3125
0.3750
0.2078
0.2408
0.3026
0.3643
0.174
0.200
0.257
0.312
0.161
0.184
0.239
0.293
0.146
0.175
0.194
0.219
0.104
0.125
0.139
0.156
0.188
0.225
0.250
0.281
0.146
0.175
0.194
0.219
11/32
13/32
15/32
1/2
7/16
17/32
19/32
11/16
5/16
3/8
7/16
15/32
13/32
1/2
9/16
5/8

Machine Screws

Nominal Screw Size O thru l2 1/4 thru 3/4
Nominal Screw Length Tolerance on Length
Up to 1/2 in., Incl.
Over 1/2 to 1 in., Incl.
Over 1 to 2 in., Incl.
Over 2 in.
-0.02
-0.03
-0.06
-0.09
-0.03
-0.03
-0.06
-0.09

Type A – AB

Nominal Screw Length Tolerance on Length
Up to 1 in., Incl.
Over 1 in.
+ 0.03
+ 0.05

Type B, F, H-L 1, 25 and 23

Nominal Screw Length Tolerance on Length
Up to 3/4 in., Incl.
Over 3/4 to 1-1/2 in., Incl.
– 0.03
– 0.05

Type U

Nominal Screw Length Tolerance on Length
Up to 3/8 in., Incl.
Over 3/8 in.
+ 0.02
+ 0.03

Wood Screws

Nominal Screw Length Tolerance on Length
Up to 5/8in., Incl.
Over 5/8 to l-1/2 in., Incl.
Over l-1/2 to 2-3/4 in., Incl.
Over 2-3/4 to 5 in., Incl.
-0.03
-0.05
-0.06
-0.09

Threads For Self Tappings Screws

Type A

Nominal Size or
Basic Screw Diameter
Threads
per Inch
D d L
Major
Diameter
Minor
Diameter
These Lengths or Shorter Have AB Threads
Max. Min. Max. Min. 90°
Heads
Csk
Heads
6 0.139
7 0.155
8 0.165
10 0.192
12 0.218
14 0.252
20 0.330
24 0.385
18
16
15
12
11
10
9
9
0.141
0.158
0.168
0.194
0.221
0.254
0.333
0.390
0.136
0.152
0.162
0.188
0.215
0.248
0.327
0.383
0.102
0.114
0.123
0.133
0.162
0.185
0.234
0.291
0.096
0.108
0.116
0.126
0.155
0.178
0.226
0.282
1/4
5/16
3/8
3/8
7/16
1/2
11/16
3/4
5/16
3/8
7/16
1/2
9/16
5/8
13/16
1

Type AB

Nominal Size or
Basic Screw Diameter
Threads
per Inch
D d L
Major
Diameter
Minor
Diameter
These Lengths or Shorter Have AB Threads
Max. Min. Max. Min. 90°
Heads
Csk
Heads
4 0.1120
6 0.1380
8 0.1640
10 0.1900
12 0.2160
1/4 0.2500
5/16 0.3125
3/8 0.3750
24
20
18
16
14
14
12
12
0.114
0.139
0.188
0.189
0.215
0.246
0.315
0.380
0.110
0.135
0.161
0.183
0.209
0.240
0.306
0.371
0.086
0.104
0.122
0.141
0.164
0.192
0.244
0.309
0.082
0.099
0.116
0.135
0.157
0.185
0.236
0.299
3/16
7/32
9/32
21/64
3/8
13/32
5/8
3/8
7/32
17/64
21/64
3/8
13/32
15/32
3/4
29/32

Type 25

Type B

Nominal Size or
Basic Screw Diameter
Threads
per
Inch
D d P S L
Major
Diameter
Minor
Diameter
Point
Diameter
Point Taper Length Determinant
Length for
Point Taper
Minimum Practical
Screw Length
For Short Screws For Long Screws
Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. 90°
Heads
Csk Heads 90°
Heads
Csk Heads
2 0.0860
4 0.1120
6 0.1380
8 0.1640
10 0.1900
12 0.2160
14 0.2500
5/16 0.3125
3/8 0.3750
32
24
20
18
16
14
14
12
12
0.088
0.114
0.139
0.166
0.189
0.215
0.246
0.315
0.380
0.084
0.110
0.135
0.161
0.183
0.209
0.240
0.306
0.371
0.064
0.086
0.104
0.122
0.141
0.164
0.192
0.244
0.309
0.060
0.082
0.099
0.116
0.135
0.157
0.185
0.236
0.299
0.058
0.079
0.095
0.112
0.130
0.152
0.179
0.230
0.293
0.054
0.074
0.089
0.106
0.123
0.145
0.171
0.222
0.285
0.062
0.083
0.100
0.111
0.125
0.143
0.143
0.167
0.167
0.047
0.063
0.075
0.083
0.094
0.107
0.107
0.125
0.125
0.078
0.104
0.125
0.139
0.156
0.179
0.179
0.196
0.196
0.062
0.083
0.100
0.111
0.125
0.143
0.143
0.161
0.161
7/64
3/16
1/4
5/16
3/8
7/16
1/2
15/32
17/32
3/16
1/4
5/16
7/16
1/2
9/16
5/8
19/32
11/16
7/64
9/64
11/64
3/16
15/64
9/32
9/32
27/32
15/16
5/32
3/16
1/4
1/4
5/16
3/8
3/8
31/32
1 1/8

Type High-Low
Self Tapping Screws

Nominal Diameter
and Thread
D B P Head Size
High
Thread Diameter
Low
Thread Diameter
Point Diameter
4-24 .105-.115 .086 .061-070 3
6-19 .135-.145 .108 .080-.090 5*
8-18 .160-.170 .130 .095-.105 6
10-16 .185-.195 .145 .099-.110 8
1/4-15 .250.260 .200 .161-175 1/4

*Special Dimensions for Pan-Head

Pan Head

Nominal
Size
A H M G Phillips
Driver Size
Diameter of Head Height of Head Dimensions of Recess
Recessed Diameter Depth
Max Min. Max Min. Max Min. Max Min.
4* .193 .180 .071 .062 .112 .099 .062 .053 1
6 .254 .240 .097 .087 .158 .145 .072 .046 2
8 .270 .256 .097 .087 .166 .153 .080 .055 2
10 .322 .306 .115 .105 .182 .169 .097 .071 2
1/4 .492 .473 .175 .162 .259 .246 .144 .118 3

*No. 2 Head

Hex Washer Head

Nominal Size A W H F U
Width
Across Flats
Width
Across
Corners
Height of
Head
Diameter of
Washer
Thickness of
Washer
Max. Min. Min. Max. Min. Max. Min. Max. Min.
4 .125 .120 .134 .055 .044 .177 .163 .016 .010
6 .188 .181 .202 .070 .058 .260 .240 .025 .015
8 .250 .244 .272 .093 .080 .328 .302 .025 .015
10 .250 .244 .272 .110 .096 .348 .322 .031 .019

Wing Screws

Basic
Screw
Dia.
Thrd per Inch S H W d D G T L
Wing Spread Wing Hght Wing Thick. Shank
Dia.
Shank Dia. Hght Stock Thick. Practical Screw Lngth
Max Min. Max Min. Max Min. Max Min. Max Min. Max Min. Max Min. Max Min.
8
10
1/4
5/16
32
24
20
18
0.78
0.90
1.09
1.31
0.72
0.84
1.03
1.25
0.40
0.46
0.46
0.62
0.34
0.40
0.40
0.56
0.18
0.21
0.26
0.29
0.12
0.15
0.20
0.23
0.35
0.35
0.47
0.57
0.31
0.31
0.43
0.53
0.40
0.53
0.61
0.68
0.34
0.47
0.55
0.62
0.21
0.22
0.24
0.29
0.14
0.16
0.18
0.23
0.04
0.04
0.04
0.07
0.03
0.03
0.03
0.05
0.75
1.00
1.50
1.50
0.38
0.38
0.50
0.50

Hex Washer Slotted

Self Piercing Screws

Size A W H F U J T D d
Width
Across Flats
Width
Across
Corner
Head Height Washer Diam. Washer Thickness Slot Width Slot Depth Major Diam. Minor Diam.
Max. Min. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min.
6-18
7-16
8-15
10-12
.250
.250
.250
.258
.244
.244
.244
.244
.272
.272
.272
.272
.093
.093
.110
.110
.080
.080
.096
.096
.328
.328
.348
.414
.302
.302
.322
.384
.025
.029
.031
.031
.015
.017
.019
.019
.048
.048
.054
.054
.039
.039
.045
.045
.053
.062
.074
.074
.033
.040
.052
.052
.141
.158
.168
.194
.136
.152
.162
.188
.102
.114
.123
.133
.096
.108
.116
.126