標稱
Nominalsize

1級螺紋用下孔徑 JIS class 1 drill hole dia

2級螺紋用下孔徑 JIS class 2 drill hole dia

R精度
R limits

最小～最大咬合率
Min～Max (thread overlap%)

R精度
R limits

最小～最大咬合率
Min～Max (thread overlap%)

M2.5×0.45

R2

2.25∼2.29

(100∼80)

R4

2.28∼2.33

(100∼75)

M2.6×0.45

2

2.35∼2.39

(100∼80)

4

2.38∼2.43

(100∼75)

M3.0×0.5

R3

2.74∼2.78

(100∼80)

R5

2.76∼2.81

(100∼75)

M3.5×0.6

3

3.18∼3.21

(100∼85)

5

3.20∼3.26

(100∼75)

M4.0×0.7

R4

3.63∼3.67

(100∼85)

R6

3.65∼3.70

(100∼85)

M5.0×0.8

4

4.57∼4.62

(100∼85)

6

4.59∼4.66

(100∼80)

M6.0×1.0

4

5.45∼5.51

(100∼85)

R7

5.48∼5.57

(100∼80)

M7.0×1.0

4

6.45∼6.51

(100∼85)

7

6.48∼6.57

(100∼80)

M8.0×1.25

R5

7.31∼7.38

(100∼85)

7

7.34∼7.41

(100∼85)

M8.0×1.0

R4

7.45∼7.51

(100∼85)

7

7.48∼7.57

(100∼80)

M10×1.5

R5

9.16∼9.22

(100∼90)

7

9.18∼9.28

(100∼85)

M10×1.25

5

9.31∼9.38

(100∼85)

7

9.34∼9.41

(100∼85)

M10×1.0

5

9.46∼9.52

(100∼85)

7

9.48∼9.57

(100∼80)

M12×1.75

5

11.01∼11.08

(100∼90)

R8

11.05∼11.15

(100∼85)

M12×1.5

5

11.16∼11.22

(100∼90)

R7

11.18∼11.28

(100∼85)

M12×1.25

5

11.31∼11.38

(100∼85)

7

11.34∼11.41

(100∼85)

M12×1.0

5

11.46∼11.52

(100∼85)

7

11.48∼11.57

(100∼80)

M14×2.0

R6

12.83∼12.95

(100∼90)

R10

12.92∼13.04

(100∼85)

M14×1.5

R5

13.16∼13.22

(100∼90)

R9

13.21∼13.30

(100∼85)

M16×2.0

R6

14.87∼14.95

(100∼90)

R10

14.92∼15.04

(100∼85)

M16×1.5

R5

15.16∼15.22

(100∼90)

R9

15.21∼15.30

(100∼80)

M18×2.5

R6

16.57∼16.67

(100∼90)

R11

16.63∼16.78

(100∼85)

M18×1.5

6

17.17∼17.23

(100∼90)

R10

17.22∼17.31

(100∼85)

M20×2.5

6

18.57∼18.67

(100∼90)

R11

18.63∼18.78

(100∼85)

M20×1.5

6

19.17∼19.23

(100∼90)

R10

19.22∼19.31

(100∼85)

標稱
Nominalsize

3B級螺紋用下孔徑 JIS class 3B drill hole dia

2B級螺紋用下孔徑 JIS class 2B drill hole dia

R精度
R limits

最小～最大咬合率
Min～Max (thread overlap%)

R精度
R limits

最小～最大咬合率
Min～Max (thread overlap%)

No.4-40UNC

R3

2.50∼2.58

(100∼70)

R5

2.52∼2.60

(100∼70)

No.5-40UNC

R3

2.83∼2.91

(100∼70)

R5

2.86∼2.93

(100∼70)

No.5-44UNF

3

2.87∼2.94

(100∼70)

4

2.88∼2.95

(100∼70)

No.6-32UNC

R3

3.06∼3.14

(100∼75)

R5

3.09∼3.17

(100∼75)

No.6-40UNF

3

3.16∼3.22

(100∼75)

5

3.19∼3.26

(100∼70)

No.8-32UNC

R4

3.74∼3.82

(100∼75)

R6

3.76∼3.84

(100∼75)

No.8-36UNF

4

3.79∼3.86

(100∼75)

5

3.80∼3.88

(100∼75)

No.10-24UNC

R4

4.24∼4.32

(100∼80)

R6

4.26∼4.35

(100∼80)

No.10-32UNF

4

4.40∼4.46

(100∼80)

5

4.41∼4.48

(100∼80)

No.12-24UNC

R4

4.90∼4.96

(100∼85)

R6

4.92∼5.01

(100∼80)

No.12-28UNF

4

4.99∼5.06

(100∼80)

5

5.00∼5.08

(100∼80)

1/4-20UNC

R4

5.64∼5.74

(100∼80)

R6

5.66∼5.76

(100∼80)

1/4-28UNF

4

5.85∼5.92

(100∼80)

5

5.86∼5.93

(100∼80)

5/16-18UNC

R5

7.15∼7.24

(100∼85)

R7

7.18∼7.29

(100∼80)

5/16-24UNF

5

7.36∼7.43

(100∼85)

6

7.38∼7.46

(100∼80)

3/8-16UNC

R5

8.63∼8.73

(100∼85)

R7

8.66∼8.78

(100∼80)

3/8-24UNF

5

8.95∼9.02

(100∼85)

6

8.96∼9.05

(100∼80)

7/16-14UNC

R5

10.06∼10.19

(100∼85)

R7

10.11∼10.25

(100∼80)

7/16-20UNF

5

10.41∼10.49

(100∼85)

7

10.44∼10.54

(100∼80)

1/2-13UNC

R6

11.60∼11.68

(100∼90)

R8

11.62∼11.78

(100∼80)

1/2-20UNF

5

12.00∼12.05

(100∼90)

7

12.02∼12.12

(100∼80)

9/16-12UNC

R8

13.11∼13.24

(100∼85)

R10

13.14∼13.27

(100∼85)

9/16-18UNF

7

13.53∼13.58

(100∼90)

9

13.55∼13.66

(100∼80)

5/8-11UNC

R8

14.58∼14.67

(100∼90)

R11

14.62∼14.76

(100∼85)

5/8-18UNF

7

15.11∼15.17

(100∼90)

9

15.14∼15.25

(100∼80)

3/4-10UNC

R9

17.63∼17.74

(100∼90)

R12

17.67∼17.88

(100∼80)

3/4-16UNF

7

18.18∼18.25

(100∼90)

10

18.22∼18.32

(100∼85)

7/8-9UNC

R9

20.64∼20.75

(100∼90)

R12

20.68∼20.85

(100∼85)

7/8-14UNF

8

21.23∼21.27

(100∼95)

11

21.27∼21.38

(100∼85)

1"-8UNC

R10

23.61∼23.74

(100∼90)

R13

23.65∼23.84

(100∼85)

1"-12UNF

9

24.24∼24.32

(100∼90)

12

24.28∼24.41

(100∼85)