THREADING THEORY


THREADING THEORY…. IN TPI & PITCH NO. 1 TO 12 AND 1/8" TO 6" IN DIMATER

Size

Equivalent to mm

BSW

BSF

UNC

UNF

PITCH

PITCH

PITCH

PITCH

TPI

INCH

METRIC

TPI

INCH

METRIC

TPI

INCH

METRIC

TPI

INCH

METRIC

No. 1

1.854

-

-

-

-

-

-

64

0.016

0.397

72

0.014

0.353

No. 2

2.184

-

-

-

-

-

-

56

0.018

0.454

64

0.016

0.397

No. 3

2.515

-

-

-

-

-

-

48

0.021

0.529

56

0.018

0.454

No. 4

2.845

-

-

-

-

-

-

40

0.025

0.635

48

0.021

0.529

No. 5

3.175

-

-

-

-

-

-

40

0.025

0.635

44

0.023

0.577

No. 6

3.505

-

-

-

-

-

-

32

0.031

0.794

40

0.025

0.635

No. 8

4.166

-

-

-

-

-

-

32

0.031

0.794

36

0.028

0.706

No. 10

4.826

-

-

-

-

-

-

24

0.041

1.058

32

0.031

0.794

No. 12

5.486

-

-

-

-

-

-

24

0.041

1.058

28

0.036

0.907

1/8"

3.175

40

0.025

0.635

-

-

-

-

-

-

-

-

-

3/16"

4.762

24

0.041

1.058

32

0.031

0.794

-

-

-

-

-

-

1/4"

6.350

20

0.050

1.270

26

0.038

0.977

20

0.050

1.270

28

0.036

0.907

5/16"

7.938

18

0.055

1.411

22

0.045

1.154

18

0.055

1.411

24

0.041

1.058

3/8"

9.525

16

0.062

1.588

20

0.050

1.270

16

0.062

1.588

24

0.041

1.058

7/16"

11.112

14

0.071

1.814

18

0.055

1.411

14

0.071

1.814

20

0.050

1.270

1/2"

12.700

20

0.083

2.117

16

0.062

1.588

13

0.077

1.954

20

0.050

1.270

9/16"

14.288

12

0.083

2.117

16

0.062

1.588

12

0.083

2.117

18

0.055

1.411

5/8"

15.875

11

0.091

2.309

14

0.071

1.814

11

0.091

2.309

18

0.055

1.411

11/16"

17.462

11

0.091

2.309

14

0.071

1.814

-

-

-

-

-

-

3/4"

19.050

10

0.100

2.540

12

0.083

2.117

10

0.100

2.540

16

0.062

1.588

7/8"

22.225

9

0.111

2.822

11

0.091

2.309

9

0.111

2.822

14

0.071

1.814

1"

25.400

8

0.125

3.175

10

0.100

2.540

8

0.125

3.175

12

0.083

2.117

1.1/8"

28.575

7

0.143

3.629

9

0.111

2.872

7

0.143

3.629

12

0.083

2.117

1.1/4"

31.750

7

0.143

3.629

9

0.111

2.872

7

0.143

3.629

12

0.083

2.117

1.3/8"

34.925

6

0.166

4.233

8

0.125

3.175

6

0.166

4.233

12

0.083

2.117

1.1/2"

38.100

6

0.166

4.233

8

0.125

3.175

6

0.166

4.233

12

0.083

2.117

1.5/8"

41.275

5

0.200

5.080

8

0.125

3.175

-

-

-

-

-

-

1.3/4"

44.450

5

0.200

5.080

7

0.143

3.629

5

0.200

5.080

-

-

-

2"

50.800

5

0.222

5.644

7

0.143

3.629

4.5

0.222

5.644

-

-

-

2.1/4"

57.150

4

0.250

6.350

6

0.166

4.233

4.5

0.222

5.644

-

-

-

2.1/2"

63.500

4

0.250

6.350

6

0.166

4.233

4

0.250

6.350

-

-

-

2.3/4"

69.850

4

0.285

7.257

5

0.166

4.233

4

0.250

6.350

-

-

-

3"

76.200

4

0.285

7.257

5

0.200

5.080

4

0.250

6.350

-

-

-

3.1/2"

88.900

3

0.308

7.832

-

-

-

-

-

-

-

-

-

4"

101.600

3

0.333

8.458

-

-

-

-

-

-

-

-

-

5"

127.000

3

0.363

9.220

-

-

-

-

-

-

-

-

-

6"

152.400

3

0.400

10.160

-

-

-

-

-

-

-

-

-