RECOMMENDED TAP DRILL HOLE SIZE

○ Metric Coarse Screw Threads

Nominalsize

Drill dia

JIS Class 2drillholedia

JIS Class 2internal thread minor dia

Min

Max

M2×0.4

1.6

1.65(80%)

1.567

1.679

M2.2×0.45

1.75

1.83(75%)

1.713

1.838

M2.5×0.45

2.1

2.13(75%)

2.013

2.138

M3×0.5

2.5

2.59(75%)

2.459

2.599

M3.5×0.6

2.9

3.01(75%)

2.850

3.010

M4×0.7

3.3

3.39(80%)

3.242

3.422

M4.5×0.75

3.8

3.85(80%)

3.688

3.878

M5×0.8

4.2

4.31(80%)

4.134

4.334

M6×1.0

5

5.13(80%)

4.917

5.153

M7×1.0

6

6.13(80%)

5.917

6.153

M8×1.25

6.8

6.85(85%)

6.647

6.912

M9×1.25

7.8

7.85(85%)

7.647

7.912

M10×1.5

8.5

8.62(85%)

8.376

8.676

M11×1.5

9.5

9.62(85%)

9.376

9.676

M12×1.75

10.3

10.40(85%)

10.106

10.441

M14×2.0

12

12.2(85%)

11.835

12.210

M16×2.0

14

14.2(85%)

13.835

14.210

M18×2.5

15.5

15.7(85%)

15.294

15.744

M20×2.5

17.5

17.7(85%)

17.294

17.744

M22×2.5

19.5

19.7(85%)

19.294

19.744

M24×3.0

21

21.2(85%)

20.752

21.252

M27×3.0

24

24.2(85%)

23.752

24.252

M30×3.5

26.5

26.6(90%)

26.211

26.771

M33×3.5

29.5

29.6(90%)

29.211

29.771

M36×4.0

32

32.1(90%)

31.670

32.270

M39×4.0

35

35.1(90%)

34.670

35.270

M42×4.5

37.5

37.6(90%)

37.129

37.799

M45×4.5

40.5

40.6(90%)

40.129

40.799

M48×5.0

43

43.1(90%)

42.587

43.297

M52×5.0

47

47.1(90%)

46.587

47.297

M56×5.5

50.5

50.6(90%)

50.046

50.796

M60×5.5

54.5

54.6(90%)

54.046

54.796

M64×6.0

58

58.1(90%)

57.505

58.305

M68×6.0

62

62.1(90%)

61.505

62.305

○ Metric Fine Screw Threads

Nominalsize

Drill dia

JIS Class 2drillholedia

JIS Class 2internal thread minor dia

Min

Max

M2.5×0.35

2.2

2.22(75%)

2.121

2.221

M3×0.35

2.7

2.72(75%)

2.621

2.721

M3.5×0.35

3.2

3.22(75%)

3.121

3.221

M4×0.5

3.5

3.59(75%)

3.459

3.599

M4.5×0.5

4

4.09(75%)

3.959

4.099

M5×0.5

4.5

4.59(75%)

4.459

4.599

M5.5×0.5

5

5.09(75%)

4.959

5.099

M6×0.75

5.3

5.35(80%)

5.188

5.378

M7×0.75

6.3

6.35(80%)

6.188

6.378

M8×1.0

7

7.13(80%)

6.917

7.153

M8×0.75

7.3

7.35(80%)

7.188

7.378

M9×1.0

8

8.13(80%)

7.917

8.153

M9×0.75

8.3

8.35(80%)

8.188

8.378

M10×1.25

8.8

8.85(85%)

8.647

8.912

M10×1.0

9

9.13(80%)

8.917

9.153

M10×0.75

9.3

9.35(80%)

9.188

9.378

M11×1.0

10

10.13(80%)

9.917

10.153

M11×0.75

10.3

10.35(80%)

10.188

10.378

M12×1.5

10.5

10.62(85%)

10.376

10.676

M12×1.25

10.8

10.85(85%)

10.647

10.912

M12×1.0

11

11.13(80%)

10.917

11.153

M14×1.5

12.5

12.62(85%)

12.376

12.676

M14×1.0

13

13.13(80%)

12.917

13.153

M15×1.5

13.5

13.62(85%)

13.376

13.676

M15×1.0

14

14.13(80%)

13.917

14.153

M16×1.5

14.5

14.62(85%)

14.376

14.676

M16×1.0

15

15.13(80%)

14.917

15.153

M17×1.5

15.5

15.62(85%)

15.376

15.676

M17×1.0

16

16.13(80%)

15.917

16.153

M18×2.0

16

16.2(85%)

15.835

16.210

M18×1.5

16.5

16.62(85%)

16.376

16.676

M18×1.0

17

17.13(80%)

16.917

17.153

M20×2.0

18

18.2(85%)

17.835

18.210

M20×1.5

18.5

18.62(85%)

18.376

18.676

M20×1.0

19

19.13(80%)

18.917

19.153

✽D1=表示JIS 6H (2級)內螺紋之內徑 ✽D1=Minor dia of JIS 6H (Class 2) internal thread



○ Metric Fine Screw Threads

Nominalsize

Drill dia

JIS Class 2drillholedia

JIS Class 2internal thread minor dia

Min

Max

M22×2

20

20.2(85%)

19.835

20.210

M22×1.5

20.5

20.62(85%)

20.376

20.676

M22×1

21

21.13(80%)

20.917

21.153

M24×2

22

22.2(85%)

21.835

22.210

M24×1.5

22.5

22.62(85%)

22.376

22.676

M24×1

23

23.13(80%)

22.917

23.153

M25×2

23

23.2(85%)

22.835

23.210

M25×1.5

23.5

23.62(85%)

23.376

23.676

M25×1

24

24.13(80%)

23.917

24.153

M26×1.5

24.5

24.62(85%)

24.376

24.676

M27×2

25

25.2(85%)

24.835

25.210

M27×1.5

25.5

25.62(85%)

25.376

25.676

M27×1

26

26.13(80%)

25.917

26.153

M28×2

26

26.2(85%)

25.835

26.210

M28×1.5

26.5

26.62(85%)

26.376

26.676

M28×1

27

27.13(80%)

26.917

27.153

M30×3

27

27.2(85%)

26.752

27.252

M30×2

28

28.2(85%)

27.835

28.210

M30×1.5

28.5

28.62(85%)

28.376

28.676

M30×1

29

29.13(80%)

28.917

29.153

M32×2

30

30.2(85%)

29.835

30.210

M32×1.5

30.5

30.62(85%)

30.376

30.676

M33×3

30

30.2(85%)

29.752

30.252

M33×2

31

31.2(85%)

30.835

31.210

M33×1.5

31.5

31.62(85%)

31.376

31.676

M35×1.5

33.5

33.62(85%)

33.376

33.676

M36×3

33

33.2(85%)

32.752

33.252

M36×2

34

34.2(85%)

33.835

34.210

M36×1.5

34.5

34.62(85%)

34.376

34.676

M38×1.5

36.5

36.62(85%)

36.376

36.676

M39×3

36

36.2(85%)

35.752

36.252

M39×2

37

37.2(85%)

36.835

37.210

M39×1.5

37.5

37.62(85%)

37.376

37.676

M40×3

37

37.2(85%)

36.752

37.252

M40×2

38

38.2(85%)

37.835

38.210

M40×1.5

38.5

38.62(85%)

38.376

38.676

M42×4

38

38.1(85%)

37.670

38.270

M42×3

39

39.2(85%)

38.752

39.252

M42×2

40

40.2(85%)

39.835

40.210

M42×1.5

40.5

40.62(85%)

40.376

40.676

○Metric Fine Screw Threads

Nominalsize

Drill dia

JIS Class 2drillholedia

JIS Class 2internal thread minor dia

Min

Max

M45×4

41

41.1(90%)

40.670

41.270

M45×3

42

42.2(85%)

41.752

42.252

M45×2

43

43.2(85%)

42.835

43.210

M45×1.5

43.5

43.62(85%)

43.376

43.676

M48×4

44

44.1(90%)

43.670

44.270

M48×3

45

45.2(85%)

44.752

45.252

M48×2

46

46.2(85%)

45.835

46.210

M48×1.5

46.5

46.62(85%)

46.376

46.676

M50×3

47

47.2(85%)

46.752

47.252

M50×2

48

48.2(85%)

47.835

48.210

M50×1.5

48.5

48.62(85%)

48.376

48.676

M52×4

48

48.1(90%)

47.670

48.270

M52×3

49

49.2(85%)

48.752

49.252

M52×2

50

50.2(85%)

49.835

50.210

M52×1.5

50.5

50.62(85%)

50.376

50.676

M55×4

51

51.1(90%)

50.670

51.270

M55×3

52

52.2(85%)

51.752

52.252

M55×2

53

53.2(85%)

52.835

53.210

M55×1.5

53.5

53.62(85%)

53.376

53.676

M56×4

52

52.1(90%)

51.670

52.270

M56×3

53

53.2(85%)

52.752

53.252

M56×2

54

54.2(85%)

53.835

54.210

M56×1.5

54.5

54.62(85%)

54.376

54.676

M58×4

54

54.1(90%)

53.670

54.270

M58×3

55

55.2(85%)

54.752

55.252

M58×2

56

56.2(85%)

55.835

56.210

M58×1.5

56.5

56.62(85%)

56.376

56.676

M60×4

56

56.1(90%)

55.670

56.270

M60×3

57

57.2(85%)

56.752

57.252

M60×2

58

58.2(85%)

57.835

58.210

M60×1.5

58.5

58.62(85%)

58.376

58.676

M62×4

58

58.1(90%)

57.670

58.270

M62×3

59

59.2(85%)

58.752

59.252

M62×2

60

60.2(85%)

59.835

60.210

M62×1.5

60.5

60.62(85%)

60.376

60.676

M64×4

60

60.1(90%)

59.670

60.270

M64×3

61

61.2(85%)

60.752

61.252

M64×2

62

62.2(85%)

61.835

62.210

M64×1.5

62.5

62.62(85%)

62.376

62.676

✽D1=Minor dia of JIS 6H (Class 2) internal thread.



○Whitworth Coarse Screw Thread

Nominalsize

Drill dia

JIS class 2 internal thread minor dia

BSW internal thread minor dia

Line A

(Hard materials)

Line B

(Soft materials)

Min

Max

Min

Max

※W1/8-40

2.55

2.45

-

-

2.362

2.591

※W3/16-24

3.7

3.6

-

-

3.406

3.774

※W1/4-20

5.1

5.0

4.914

5.204

4.724

5.156

W5/16-18

6.6

6.5

6.340

6.670

6.129

6.588

W3/8-16

8.0

7.9

7.733

8.113

7.493

7.988

W7/16-14

9.4

9.3

9.048

9.508

8.791

9.332

W1/2-12

10.7

10.5

10.310

10.830

9.990

10.589

W9/16-12

12.3

12.0

11.898

12.418

11.575

12.176

W5/8-11

13.7

13.5

13.257

13.817

12.918

13.558

W3/4-10

16.6

16.5

16.178

16.778

15.800

16.484

W7/8-9

19.5

19.3

19.031

19.691

18.613

19.354

W1-8

22.4

22.0

21.814

22.514

21.336

22.148

W1 1/8-7

25.0

24.8

24.469

25.229

23.927

24.831

W1 1/4-7

28.3

28.0

27.644

28.404

27.102

28.006

W1 3/8-6

30.5

30.3

30.123

30.923

-

-

W1 1/2-6

33.8

33.5

33.298

34.098

32.680

33.703

W1 5/8-5

36.0

35.7

35.529

36.409

-

-

W1 3/4-5

39.2

39.0

38.704

39.584

37.943

39.136

W1 7/8-4 1/2

41.8

41.5

41.237

42.227

-

-

W2-4 1/2

45.0

44.7

44.412

45.402

43.571

44.876

• The recommended tap drill sizes indicated above are for JIS Class 2 Whitworth Threads. • ※Marked sizes are in accordance with BSW.



○Screw threads for sewing machines

Nominalsize

Drill dia

JIS class 2drill holedia.

JIS class 2 internal thread minor dia

Nominalsize

Drill dia

JIS class 2drill holedia.

JIS class 2 internal thread minor dia

Min

Max

Min

Max

SM 1/16-80

1.25

1.28(75%)

1.211

1.281

SM 1/4-24

5.20

5.25(80%)

5.086

5.266

SM 5/64-64

1.55

1.58(80%)

1.513

1.593

SM 9/32-28

6.10

6.20(80%)

6.066

6.256

SM 3/32-100

2.10

2.15(70%)

2.081

2.156

SM 9/32-20

5.70

5.82(80%)

5.631

5.824

SM 3/32-56

1.85

1.91(80%)

1.841

1.936

SM 5/16-28

6.90

6.00(80%)

6.860

7.050

SM 1/8-44

2.50

2.58(80%)

2.485

2.605

SM 5/16-24

6.70

6.84(80%)

6.674

6.864

SM 1/8-40

2.45

2.52(80%)

2.421

2.551

SM 5/16-18

6.30

6.38(85%)

6.254

6.444

SM 9/64-40

2.85

2.91(80%)

2.818

2.948

SM 3/8-28

8.50

8.58(80%)

8.447

8.637

SM 11/64-40

3.65

3.71(80%)

3.612

3.742

SM 3/8-18

7.90

7.97(85%)

7.843

8.053

SM 3/16-32

3.90

3.94(80%)

3.820

3.980

SM 7/16-28

10.10

10.17(80%)

10.034

10.224

SM 3/16-28

3.70

3.82(80%)

3.684

3.844

SM 7/16-16

9.30

9.36(85%)

9.220

9.440

SM 7/32-32

4.70

4.73(80%)

4.614

4.774

SM 1/2-28

11.70

11.76(80%)

11.622

11.812

SM 15/64-28

4.90

5.01(80%)

4.875

5.055

SM 1/2-20

11.30

11.38(80%)

11.190

11.410

SM 1/4-40

5.60

5.69(80%)

5.596

5.726

SM 1/2-12

10.30

10.36(85%)

10.180

10.420

SM 1/4-28

5.30

5.41(80%)

5.272

5.452

SM 9/16-20

12.90

12.90(85%)

12.778

13.018



○Unified Coarse Screw Threads

Nominalsize

Drill dia

JIS Class 2B drill hole dia

JIS Class 2B internal thread minor dia

Min

Max

No.1-64 UNC

1.55

1.57(65%)

1.425

1.582

No.2-56 UNC

1.8

1.86(65%)

1.695

1.871

No.3-48 UNC

2.1

2.14(65%)

1.941

2.146

No.4-40 UNC

2.3

2.36(70%)

2.157

2.385

No.5-40 UNC

2.6

2.69(70%)

2.487

2.697

No.6-32 UNC

2.8

2.86(75%)

2.642

2.895

No.8-32 UNC

3.4

3.52(75%)

3.302

3.530

No.10-24UNC

3.9

3.91(80%)

3.683

3.962

No.12-24UNC

4.5

4.57(80%)

4.344

4.597

1/4-20 UNC

5.1

5.25(80%)

4.979

5.257

5/16-18 UNC

6.6

6.72(80%)

6.401

6.731

3/8-16 UNC

8.0

8.15(80%)

7.798

8.153

7/16-14 UNC

9.4

9.5(80%)

9.144

9.550

1/2-13 UNC

10.8

11.0(80%)

10.592

11.023

9/16-12 UNC

12.2

12.3(85%)

11.989

12.446

5/8-11 UNC

13.6

13.8(85%)

13.386

13.868

3/4-10 UNC

16.5

16.8(85%)

16.307

16.840

7/8-9 UNC

19.5

19.6(85%)

19.177

19.761

1-8 UNC

22.2

22.5(85%)

21.971

22.606

1 1/8-7 UNC

25.0

25.2(85%)

24.638

25.349

1 1/4-7 UNC

28.2

28.4(85%)

27.813

28.524

1 3/8-6 UNC

30.8

31.0(85%)

30.353

31.115

1 1/2-6 UNC

34.0

34.2(85%)

33.528

34.290

1 3/4-5UNC

39.5

39.8(85%)

38.964

39.827

2-4 1/2UNC

45.2

45.3(90%)

44.679

45.593

○ Unified Fine Screw Threads

Nominalsize

Drill dia

JIS Class 2B drill hole dia

JIS Class 2B internal thread minor dia

Min

Max

No.0-80UNF

1.25

1.30(65%)

1.182

1.305

No.1-72UNF

1.55

1.61(65%)

1.474

1.612

No.2-64UNF

1.85

1.90(65%)

1.756

1.912

No.3-56UNF

2.1

2.17(70%)

2.025

2.197

No.4-48UNF

2.4

2.44(70%)

2.271

2.458

No.5-44UNF

2.7

2.74(70%)

2.551

2.740

No.6-40UNF

2.9

3.02(70%)

2.820

3.022

No.8-36UNF

3.5

3.59(75%)

3.404

3.606

No.10-32UNF

4.1

4.14(80%)

3.963

4.165

No.12-28UNF

4.6

4.70(80%)

4.496

4.724

1/4-28UNF

5.5

5.56(80%)

5.360

5.588

5/16-24UNF

6.9

7.02(80%)

6.782

7.035

3/8-24UNF

8.5

8.61(80%)

8.382

8.636

7/16-20UNF

9.9

10.01(80%)

9.729

10.033

1/2-20UNF

11.5

11.60(80%)

11.329

11.607

9/16-18UNF

12.9

13.07(80%)

12.751

13.081

5/8-18UNF

14.5

14.65(80%)

14.351

14.681

3/4-16UNF

17.5

17.59(85%)

17.323

17.678

7/8-14UNF

20.5

20.6(85%)

20.270

20.675

1-12UNF

23.2

23.5(85%)

23.114

23.571

1 1/8-12UNF

26.5

26.7(80%)

26.289

26.746

1 1/4-12UNF

29.5

29.9(80%)

29.464

29.921

1 3/8-12 UNF

32.8

33.0(85%)

32.639

33.096

1 1/2-12UNF

36.0

36.2(85%)

35.814

36.271



○Unified extra fine thread & constant-pitch series with 8 & with 12 threads

Nominal size

Drill dia

ANSI Class 2B drill hole dia

ANSI Class 2B internal thread minor dia

Nominal size

Drill dia

ANSI Class 2B drill hole dia

ANSI Class 2B internal thread minor dia

Min

Max

Min

Max

No.12-32UNEF

4.7

4.7(90%)

4.623

4.826

1 1/4-18 UNEF

30.3

30.4(90%)

30.226

30.556

1/4-32UNEF

5.6

5.6(85%)

5.486

5.690

1 1/4-8 UN

28.5

28.7(90%)

28.321

28.956

5/16-32UNEF

7.1

7.2(85%)

7.087

7.264

1 3/8-18 UNEF

33.5

33.6(85%)

33.401

33.731

3/8-32UNEF

8.7

8.8(85%)

8.651

8.865

1 3/8-8 UN

31.8

31.8(90%)

31.496

32.131

7/16-28UNEF

10.2

10.25(85%)

10.135

10.338

1 1/2-18 UNEF

36.6

36.7(90%)

36.576

36.881

1/2-28UNEF

11.8

11.8(90%)

11.709

11.938

1 1/2-8 UN

35.0

35.0(90%)

34.671

35.306

9/16-24UNEF

13.2

13.3(85%)

13.132

13.386

1 5/8-18 UNEF

39.8

39.9(90%)

39.751

40.081

5/8-24UNEF

14.8

14.9(85%)

14.732

14.986

1 5/8-8 UN

38.2

38.2(90%)

37.846

38.481

3/4-20UNEF

17.8

17.8(90%)

17.678

17.958

1 5/8-12 UN

39.2

39.2(90%)

38.989

39.446

7/8-20UNEF

21.0

21.0(90%)

20.853

21.133

1 3/4-8 UN

41.3

41.3(90%)

41.021

41.656

1-20UNEF

24.1

24.2(85%)

24.028

24.308

1 3/4-12 UN

42.3

41.4(90%)

42.164

42.621

1 1/8-18UNEF

27.2

27.2(90%)

27.051

27.381

2-8 UN

47.8

47.8(85%)

47.371

48.006

1 1/8-8UN

25.5

25.5(90%)

25.146

25.781

2-12 UN

48.6

48.7(90%)

48.514

48.971



○ NPT NPS (NPSC) American Standard Pipe Threads

Nominalsize

Taper Thread

Parallel thread

NPT 
Drill dia

NPS (NPSC)

Use with reamer

Without reamer

Drill dia

mm

inch

mm

inch

mm

inch

1/16-27

5.94

0.234

6.15

0.242

6.35

0.250

1/8-27

8.33

0.328

8.43

0.332

8.74

0.344

1/4-18

10.72

0.422

11.13

0.438

11.13

0.438

3/8-18

14.27

0.562

14.27

0.562

14.68

0.578

1/2-14

17.48

0.688

17.86

0.703

18.26

0.719

3/4-14

22.63

0.891

23.01

0.906

23.42

0.922

1-11 1/2

28.58

1.125

28.98

1.141

29.36

1.156

1 1/4-11 1/2

37.31

1.469

37.69

1.484

38.10

1.500

1 1/2-11 1/2

43.26

1.703

43.66

1.719

44.45

1.750

2-11 1/2

55.17

2.172

55.58

2.188

56.36

2.219

2 1/2-8

65.48

2.578

66.27

2.609

67.46

2.656

•The drill sizes are quoted from ANSI/ASME B1.20.1-1983 pipe threads, general purpose (inch) appendix.



○ NPTF•NPSF Dryseal American Standard Pipe Threads

Nominalsize

Taper Thread

 Parallel thread

NPTF 
Drill dia

NPSF

Use with reamer

Without reamer

Drill dia

mm

inch

mm

inch

mm

inch

1/16-27

5.94

0.234

6.15

0.242

6.25

0.246

1/8-27

8.33

0.328

8.43

0.332

8.61

0.339

1/4-18

10.72

0.422

11.13

0.438

11.13

0.438

3/8-18

14.27

0.562

14.27

0.562

14.68

0.578

1/2-14

17.48

0.688

17.86

0.703

17.86

0.703

3/4-14

22.63

0.891

23.01

0.906

23.42

0.922

1-11 1/2

28.58

1.125

28.98

1.141

29.36

1.156

1 1/4-11 1/2

37.31

1.469

37.69

1.484

─

─

1 1/2-11 1/2

43.26

1.703

43.66

1.719

─

─

2-11 1/2

55.17

2.172

55.58

2.188

─

─

2 1/2-8

65.48

2.578

66.27

2.609

─

─

 •The drill sizes are quoted from ANSI B1.20.1-1976 dryseal pipe threads (inch) appendix.



○ NPSM American Standard Straight Pipe Thread

Nominalsize

Drill dia

Minor diameter

Nominalsize

Drill dia

Minor diameter

Min

Max

Min

Max

1/8-27

9.2

9.093

9.246

1-11 1/2

30.6

30.505

30.759

1/4-18

12.0

11.887

12.217

1 1/4-11 1/2

39.3

39.268

39.497

3/8-18

15.4

15.316

15.545

1 1/2-11 1/2

45.4

45.339

45.568

1/2-14

19.0

18.974

19.279

2-11 1/2

57.5

57.379

57.607

3/4-14

24.5

24.333

24.638

2 1/2-8

69.0

68.783

69.266



○(RC,PT) Taper pipe thread

Nominalsize

Drill dia

Internal thread minor dia on (min) length of useful thread

Internal thread minordiaon(min) gaugelength

Use with reamer

Without reamer

RC1/16-28

6.1

6.2

6.244

6.370

RC1/8-28

8.1

8.2

8.249

8.375

RC1/4-19

10.7

11.0

10.962

11.153

RC3/8-19

14.2

14.5

14.448

14.636

RC1/2-14

17.6

18.0

17.979

18.234

RC3/4-14

23.0

23.4

23.378

23.635

RC1-11

29.0

29.5

29.459

29.786

RC1 1/4-11

37.5

38.0

37.976

38.302

RC1 1/2-11

43.4

44.0

43.869

44.195

RC2-11

54.9

55.5

55.412

55.808

RC2 1/2-11

70.4

71.0

70.737

71.279

RC3-11

82.8

83.4

83.244

83.780

RC4-11

107.5

108.2

108.015

108.629



○Rp(PS) Parallel pipe thread

Nominalsize

Drill dia

Minor diameter of JIS internal thread (D1)

Min

Max

Rp 1/16-28

6.5

6.490

6.632

Rp 1/8-28

8.5

8.495

8.637

Rp 1/4-19

11.4

11.341

11.549

Rp 3/8-19

14.9

14.846

15.054

Rp 1/2-14

18.6

18.489

18.773

Rp 3/4-14

24.0

23.975

24.259

Rp 1-11

30.2

30.110

30.472

Rp 1 1/4-11

38.8

38.771

39.133

Rp 1 1/2-11

44.7

44.664

45.026

Rp 2-11

56.5

56.475

56.837

Rp 2 1/2-11

72.2

72.010

72.442

Rp 3-11

84.9

84.710

85.142

Rp 4/11

110.0

109.856

110.288

○G(PF) Parallel pipe thread

Nominalsize

Drill dia

Minor diameterof JIS internal thread (D1)

Min

Max

G1/16-28

6.7

6.561

6.843

G1/8-28

8.7

8.566

8.848

G1/4-19

11.7

11.445

11.890

G3/8-19

15.2

14.950

15.395

G1/2-14

19.0

18.631

19.172

G5/8-14

21.0

20.587

21.128

G3/4-14

24.5

24.117

24.658

G7/8-14

28.2

27.877

28.418

G1-11

30.6

30.291

30.931

G1 1/8-11

35.2

34.939

35.579

G1 1/4-11

39.2

38.952

39.592

G1 1/2-11

45.0

44.845

45.485

G1 3/4-11

51.0

50.788

51.428

G2-11

57.0

56.656

57.296

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