Keyway Chart


The following tables show standard dimensions for keys and their grooves.

 

Metric – Rectangular
B.S.4235 : PART 1 : 1972

Nominal Shaft Diam
Key
Size
Dimensions (mm)
Over
To (incl.)
A
B
C
D
E
F
R
10
12
4 x 4
3.970
4.000
2.5
2.6
3.985
4.015
1.8
1.9
4.030
3.970
0.16
12
17
5 x 5
4.970
5.000
3.0
3.1
4.985
5.015
2.3
2.4
5.030
4.970
0.25
17
22
6 x 6
5.970
6.000
3.5
3.6
5.985
6.015
2.8
2.9
6.030
5.970
0.25
22
30
8 x 7
7.964
8.000
4.0
4.2
7.982
8.018
3.3
3.5
8.000
7.964
7.000
6.910
0.25
30
38
10 x 8
9.964
10.000
5.0
5.2
9.982
10.018
3.3
3.5
10.000
9.964
8.000
7.910
0.40
38
44
12 x 8
11.957
12.000
5.0
5.2
11.979
12.021
3.3
3.5
12.000
11.957
8.000
7.910
0.40
44
50
14 x 9
13.957
14.000
5.5
5.7
13.979
14.021
3.8
4.0
14.000
13.957
9.000
8.910
0.40
50
58
16 x 10
15.957
16.000
6.0
6.2
15.979
16.021
4.3
4.5
16.000
15.957
10.000
9.910
0.40
58
65
18 x 11
17.957
18.000
7.0
7.2
17.979
18.021
4.4
4.6
18.000
17.957
11.000
10.890
0.40
65
75
20 x 12
19.948
20.000
7.5
7.7
19.974
20.026
4.9
5.1
20.000
19.948
12.000
11.890
0.60
75
85
22 x 14
21.948
22.000
9.0
9.2
21.974
22.026
5.4
5.6
22.000
21.948
14.000
13.890
0.60
85
95
25 x 14
24.948
25.000
9.0
9.2
24.974
25.026
5.4
5.6
25.000
24.948
14.000
13.890
0.60
95
110
28 x 16
27.948
28.000
10.0
10.2
27.974
28.026
6.4
6.6
28.000
27.948
16.000
15.890
0.60
110
130
32 x 18
31.938
32.000
11.0
11.2
31.969
32.031
7.4
7.6
32.000
31.938
18.000
17.890
0.60
130
150
36 x 20
35.938
36.000
12.0
12.3
35.969
36.031
8.4
8.7
36.000
35.938
20.000
19.870
1.00
150
170
40 x 22
39.938
40.000
13.0
13.3
39.969
40.031
9.4
9.7
40.000
39.938
22.000
21.870
1.00
170
200
45 x 25
44.938
45.000
15.0
15.3
44.969
45.031
10.4
10.7
45.000
44.938
25.000
24.870
1.00
200
230
50 x 28
49.938
50.000
17.0
17.3
49.969
50.031
11.4
11.7
50.000
49.938
28.000
27.870
1.00

 

Imperial – Rectangular
B.S.46 : PART 1 : 1958

Nominal Shaft Diam
Key
Size
Dimensions (Inches)
Over
To (incl.)
A
B
C
D
E
F
R
1
1 1/4
5/16 x 1/4
0.311
0.312
0.146
0.152
0.312
0.313
0.112
0.118
0.314
0.312
0.253
0.250
0.010
1 1/4
1 1/2
3/8 x 1/4
0.374
0.375
0.150
0.156
0.375
0.376
0.108
0.114
0.377
0.375
0.253
0.250
0.010
1 1/2
1 3/4
7/16 x 5/16
0.437
0.438
0.186
0.192
0.438
0.439
0.135
0.141
0.440
0.438
0.315
0.312
0.020
1 3/4
2
1/2 x 5/16
0.499
0.500
0.190
0.196
0.500
0.501
0.131
0.137
0.502
0.500
0.315
0.312
0.020
2
2 1/2
5/8 x 7/16
0.624
0.625
0.260
0.266
0.625
0.626
0.185
0.191
0.627
0.625
0.441
0.438
0.020
2 1/2
3
3/4 x 1/2
0.749
0.750
0.299
0.305
0.750
0.751
0.209
0.215
0.752
0.750
0.503
0.500
0.020
3
3 1/2
7/8 x 5/8
0.874
0.875
0.370
0.376
0.875
0.876
0.264
0.270
0.877
0.875
0.629
0.625
0.062
3 1/2
4
1 x 3/4
0.999
1.000
0.441
0.447
1.000
1.001
0.318
0.324
1.003
1.000
0.754
0.750
0.062
4
5
1 1/4 x 7/8
1.248
1.250
0.518
0.524
1.250
1.252
0.366
0.372
1.253
1.250
0.879
0.875
0.062
5
6
1 1/2 x 1
1.498
1.500
0.599
0.605
1.500
1.502
0.412
0.418
1.504
1.500
1.006
1.000
0.062

Imperial – Square
B.S.46 : PART 1 : 1958

Nominal Shaft Diam
Key
Size
Dimensions (Inches)
Over
To (incl.)
A
B
C
D
E
F
R
1/4
1/2
1/8 x 1/8
0.124
0.125
0.072
0.078
0.125
0.126
0.060
0.066
0.127
0.125
0.010
1/2
3/4
3/16 x 3/16
0.187
0.188
0.107
0.113
0.188
0.189
0.088
0.094
0.190
0.188
0.010
3/4
1
1/4 x 1/4
0.249
0.250
0.142
0.148
0.250
0.251
0.115
0.121
0.252
0.250
0.010
1
1 1/4
5/16 x 5/16
0.311
0.312
0.177
0.183
0.312
0.313
0.142
0.148
0.314
0.312
0.010
1 1/4
1 1/2
3/8 x 3/8
0.374
0.375
0.213
0.219
0.375
0.376
0.169
0.175
0.377
0.375
0.010
1 1/2
1 3/4
7/16 x 7/16
0.437
0.438
0.248
0.254
0.438
0.439
0.197
0.203
0.440
0.438
0.020
1 3/4
2
1/2 x 1/2
0.499
0.500
0.283
0.289
0.500
0.501
0.224
0.230
0.502
0.500
0.020
2
2 1/2
5/8 x 5/8
0.624
0.625
0.354
0.360
0.625
0.626
0.278
0.284
0.627
0.625
0.020
2 1/2
3
3/4 x 3/4
0.749
0.750
0.424
0.430
0.750
0.751
0.333
0.339
0.752
0.750
0.020
3
3 1/2
7/8 x 7/8
0.874
0.875
0.495
0.501
0.875
0.876
0.387
0.393
0.877
0.875
0.062
3 1/2
4
1 x 1
0.999
1.000
0.566
0.572
1.000
1.001
0.442
0.448
1.003
1.000
0.062
4
5
1 1/4 x 1 1/4
1.248
1.250
0.707
0.713
1.250
1.252
0.551
0.557
1.253
1.250
0.062
5
6
1 1/2 x 1 1/2
1.498
1.500
0.848
0.854
1.500
1.502
0.661
0.667
1.504
1.500
0.062