Bores and Keyways

In the following section you will find information on British standard keyway and bore sizes. John Kings will generally bore all wheels to a H7 tolerance unless specified by the customer. All wheels will come with grub screw fixings over keyways and at 90 degrees as standard. The standard positioning for all keyways will be in line with a tooth.

It is important to remember that on twin stranded conveyors and elevators where matched chains are used it is equally important that matched wheels are specified since this involves careful keyway cutting to ensure both wheels engage the wheel at exactly the same time. In the case of tail wheels on twin strand elevators one wheel should be keyed to the shaft and the other should run loose to compensate for any uneven strand lengths that may develop over time.

Wheels can be supplied with alternatives to keyways and plain bores such as oilite bushes, phosphor bronze bushes, plastic bushes, clamping elements and weld on hubs for use with taper lock bushes.


Table 22.1 H7 bore tolerances

Nominal hole sizes

mm

Over

3

6

10

18

30

40

50

65

80

100

120

140

160

180

200

225

250

280

315

355

inc

6

10

18

30

40

50

65

80

100

120

140

160

180

200

225

250

280

315

355

400

H7

12

15

18

21

25

30

35

40

46

52

57

0

0

0

0

0

0

0

0

0

0

0



Bores and Keyways

Table 22.2 Imperial – Rectangular B.S.46:PART 1:1958

Nominal Shaft Diam

Key

Size

Dimensions

Over

To (incl.)

A

B

C

D

E

F

R

inches

1

1 1/4

5/16 x 1/4

0.311

0.146

0.312

0.112

0.314

0.253

0.010

0.312

0.152

0.313

0.118

0.312

0.250

1 1/4

1 1/2

3/8 x 1/4

0.374

0.150

0.375

0.108

0.377

0.253

0.010

0.375

0.156

0.376

0.114

0.375

0.250

1 1/2

1 3/4

7/16 x 5/16

0.437

0.186

0.438

0.135

0.440

0.315

0.020

0.438

0.192

0.439

0.141

0.438

0.312

1 3/4

2

1/2 x 5/16

0.499

0.190

0.500

0.131

0.502

0.315

0.020

0.500

0.196

0.501

0.137

0.500

0.312

2

2 1/2

5/8 x 7/16

0.624

0.260

0.625

0.185

0.627

0.441

0.020

0.625

0.266

0.626

0.191

0.625

0.438

2 1/2

3

3/4 x 1/2

0.749

0.299

0.750

0.209

0.752

0.503

0.020

0.750

0.305

0.751

0.215

0.750

0.500

3

3 1/2

7/8 x 5/8

0.874

0.370

0.875

0.264

0.877

0.629

0.062

0.875

0.376

0.876

0.270

0.875

0.625

3 1/2

4

1 x 3/4

0.999

0.441

1.000

0.318

1.003

0.754

0.062

1.000

0.447

1.001

0.324

1.000

0.750

4

5

1 1/4 x 7/8

1.248

0.518

1.250

0.366

1.253

0.879

0.062

1.250

0.524

1.252

0.372

1.250

0.875

5

6

1 1/2 x 1

1.498

0.599

1.500

0.412

1.504

1.006

0.062

1.500

0.605

1.502

0.418

1.500

1.000


Table 22.3 Metric – Rectangular B.S.4235:PART 1:1972

Nominal Shaft Diam

Key

Dimensions

Over

To (incl.)

Size

A

B

C

D

E

F

R

mm

10

12

4 x 4

3.970

2.5

3.985

1.8

4.030

0.16

4.000

2.6

4.015

1.9

3.970

12

17

5 x 5

4.970

3.0

4.985

2.3

5.030

0.25

5.000

3.1

5.015

2.4

4.970

17

22

6 x 6

5.970

3.5

5.985

2.8

6.030

0.25

6.000

3.6

6.015

2.9

5.970

22

30

8 x 7

7.964

4.0

7.982

3.3

8.000

7.000

0.25

8.000

4.2

8.018

3.5

7.964

6.910

30

38

10 x 8

9.964

5.0

9.982

3.3

10.000

8.000

0.40

10.000

5.2

10.018

3.5

9.964

7.910

38

44

12 x 8

11.957

5.0

11.979

3.3

12.000

8.000

0.40

12.000

5.2

12.021

3.5

11.957

7.910

44

50

14 x 9

13.957

5.5

13.979

3.8

14.000

9.000

0.40

14.000

5.7

14.021

4.0

13.957

8.910

50

58

16 x 10

15.957

6.0

15.979

4.3

16.000

10.000

0.40

16.000

6.2

16.021

4.5

15.957

9.910

58

65

18 x 11

17.957

7.0

17.979

4.4

18.000

11.000

0.40

18.000

7.2

18.021

4.6

17.957

10.890

65

75

20 x 12

19.948

7.5

19.974

4.9

20.000

12.000

0.60

20.000

7.7

20.026

5.1

19.948

11.890

75

85

22 x 14

21.948

9.0

21.974

5.4

22.000

14.000

0.60

22.000

9.2

22.026

5.6

21.948

13.890

85

95

25 x 14

24.948

9.0

24.974

5.4

25.000

14.000

0.60

25.000

9.2

25.026

5.6

24.948

13.890

95

110

28 x 16

27.948

10.0

27.974

6.4

28.000

16.000

0.60

28.000

10.2

28.026

6.6

27.948

15.890

110

130

32 x 18

31.938

11.0

31.969

7.4

32.000

18.000

0.60

32.000

11.2

32.031

7.6

31.938

17.890

130

150

36 x 20

35.938

12.0

35.969

8.4

36.000

20.000

1.00

36.000

12.3

36.031

8.7

35.938

19.870

150

170

40 x 22

39.938

13.0

39.969

9.4

40.000

22.000

1.00

40.000

13.3

40.031

9.7

39.938

21.870

170

200

45 x 25

44.938

15.0

44.969

10.4

45.000

25.000

1.00

45.000

15.3

45.031

10.7

44.938

24.870

200

230

50 x 28

49.938

17.0

49.969

11.4

50.000

28.000

1.00

50.000

17.3

50.031

11.7

49.938

27.870


Table 22.4 Imperial – Square B.S.46:PART 1:1958

Nominal Shaft Diam

Key

Dimensions

Over

To (incl.)

Size

A

B

C

D

E

F

R

inches

1/4

1/2

1/8 x 1/8

0.124

0.072

0.125

0.060

0.127

0.010

0.125

0.078

0.126

0.066

0.125

1/2

3/4

3/16 x 3/16

0.187

0.107

0.188

0.088

0.190

0.010

0.188

0.113

0.189

0.094

0.188

3/4

1

1/4 x 1/4

0.249

0.142

0.250

0.115

0.252

0.010

0.250

0.148

0.251

0.121

0.250

1

1 1/4

5/16 x 5/16

0.311

0.177

0.312

0.142

0.314

0.010

0.312

0.183

0.313

0.148

0.312

1 1/4

1 1/2

3/8 x 3/8

0.374

0.213

0.375

0.169

0.377

0.010

0.375

0.219

0.376

0.175

0.375

1 1/2

1 3/4

7/16 x 7/16

0.437

0.248

0.438

0.197

0.440

0.020

0.438

0.254

0.439

0.203

0.438

1 3/4

2

1/2 x 1/2

0.499

0.283

0.500

0.224

0.502

0.020

0.500

0.289

0.501

0.230

0.500

2

2 1/2

5/8 x 5/8

0.624

0.354

0.625

0.278

0.627

0.020

0.625

0.360

0.626

0.284

0.625

2 1/2

3

3/4 x 3/4

0.749

0.424

0.750

0.333

0.752

0.020

0.750

0.430

0.751

0.339

0.750

3

3 1/2

7/8 x 7/8

0.874

0.495

0.875

0.387

0.877

0.062

0.875

0.501

0.876

0.393

0.875

3 1/2

4

1 x 1

0.999

0.566

1.000

0.442

1.003

0.062

1.000

0.572

1.001

0.448

1.000

4

5

1 1/4 x 1 1/4

1.248

0.707

1.250

0.551

1.253

0.062

1.250

0.713

1.252

0.557

1.250

5

6

1 1/2 x 1 1/2

1.498

0.848

1.500

0.661

1.504

0.062

1.500

0.854

1.502

0.667

1.500



Bores and Keyways

Table 22.5 Imperial Rectangular Taper Keyways

Shaft diameter

Key

Keyway (shaft)

Keyway (hub)

Keyway radius

D

width/height

W

H

W

h

r

Over

To/Inc

W & T

Min

Max

Min

Max

Min

Max

Min

max

inches

1/4

1/2

1/8

0.124

0.125

0.072

0.078

0.125

0.126

0.039

0.045

0.010

1/2

3/4

3/16

0.187

0.188

0.107

0.113

0.188

0.189

0.067

0.073

0.010

3/4

1

1/4

0.249

0.250

0.142

0.148

0.250

0.251

0.094

0.100

0.010

1

1 1/4

5/16

0.311

0.312

0.177

0.183

0.312

0.313

0.121

0.127

0.010

1 1/4

1 1/2

3/8

0.374

0.375

0.213

0.219

0.375

0.376

0.148

0.154

0.010

1 1/2

1 3/4

7/16

0.437

0.438

0.248

0.254

0.438

0.439

0.175

0.181

0.020

1 3/4

2

1/2

0.499

0.500

0.283

0.289

0.500

0.501

0.202

0.208

0.020

2

2 1/2

5/8

0.624

0.625

0.354

0.360

0.625

0.626

0.256

0.262

0.020

2 1/2

3

3/4

0.749

0.750

0.424

0.430

0.750

0.751

0.310

0.316

0.020

3

3 1/2

7/8

0.874

0.875

0.495

0.501

0.875

0.875

0.876

0.370

0.062

3 1/2

4

1

0.999

1.000

0.566

0.572

1.000

1.001

0.418

0.424

0.062

4

5

1 1/4

1.248

1.250

0.707

0.713

1.250

1.252

0.526

0.532

0.062

5

6

1 1/4

1.498

1.500

0.848

0.854

1.500

1.502

0.635

0.641

0.062


Table 22.6 Metric Rectangular Taper Keyways

Shaft diameter

Key

Keyway

width

depth

radius

tolerance for class of fit

shaft

hub

D

W x T

W

H

h

r

Over

Inc

width
x
thickness

Nom.

free

normal

close and
interference

nom.

tol.

nom.

tol.

max.

min.

shaft
(H9)

hub
(D10)

shaft
(N9)

hub
(J39)

shaft
and hub
(P9)

mm

22

30

8 x 7

8

+ 0.036

0

+ 0.098
+ 0.040

0

0.036

+ 0 .018
0 .018

0.015
0.051

4

+ 0.2

0

3.3

+ 0.2

0

0.25

0.16

30

38

10 x 8

10

5

3.3

0.40

0.25

38

44

12 x 8

12

+ 0.043

0

+ 0.120
+ 0.050

0

0.043

+ 0.021
0.021

0.018
0.061

5

3.3

0.40

0.25

44

50

14 x 9

14

5.5

3.8

0.40

0.25

50

58

16 x 10

16

6

4.3

0.40

0.25

58

65

18 x 11

18

7

4.4

0.40

0.25

65

75

20 x 12

20

+ 0.052

0

+ 0.149
+ 0.065

0

0.052

+ 0.026
0.026

0.022
0.074

7.5

4.9

0.60

0.40

75

85

22 x 14

22

9

5.4

0.60

0.40

85

95

25 x 14

25

9

5.4

0.60

0.40

95

110

28 x 16

28

10

6.4

0.60

0.40

110

130

32 x 18

32

+ 0.062

0

+ 0.180
+ 0.080

0

0.062

+ 0.031
0.031

0.026
0.088

11

7.4

0.60

0.40

130

150

38 x 20

38

12

+ 0.3

0

8.4

+ 0.3

0

1.00

0.70

150

170

40 x 22

40

13

9.4

1.00

0.70

170

200

45 x 25

45

15

10.4

1.00

0.70

200

230

50 x 28

50

17

11.4

1.00

0.70

230

260

56 x 32

56

+ 0.074

0

+ 0.220
+ 0.100

0

0.074

+ 0.037
0.037

0.032
0.106

20

12.4

1.60

1.20

260

290

63 x 32

63

20

12.4

1.60

1.20

290

330

70 x 36

70

22

14.4

1.60

1.20

330

380

80 x 40

80

25

15.4

2.50

2.00

380

440

90 x 45

90

+0.087

0

+ 0.260
+ 0.120

0

0.087

+ 0.043
0.043

0.037
0.124

28

17.4

2.50

2.00

440

500

100 x 50

100

31

19.5

2.50

2.00