Fastener Selection Guide
Pictorial Table of Fasteners

Metric Screw Thread Chart

Metric Tap Size

Tap Drill in Inches

Clearance Drill in Inches

M1.6 x .35

#55 (.052)

#50 (.070)

M1.8 x .35

#53 (.057)

#48 (.076)

M2 x .4

#52 (.063)

#45 (.082)

M3 x .5

#39 (.0995)

1/8 (.125)

M3.5 x .6

#32 (.116)

#28 (.140)

M4 x .7

#29 (.136)

#19 (.166)

M4.5 x .75

#25 (.1495)

#14 (.182)

M5 x .8

#18 (.169)

#7 (.201)

M6 x 1

#8 (.199)

“C” (.242)

M7 x 1

“B” (.238)

9/32 (.281)

M8 x 1.25

“I” (.272)

“P” (.323)

M8 x 1

“J” (.272)

“P” (.323)

M10 x 1.5

“K” (.339)

13/32 (.406)

M10 x 1.25

“S” (.348)

13/32 (.406)

M12 x 1.75

13/32 (.406)

31/64 (.484)

M12 x 1.25

27/64 (.421)

31/64 (.484)

M14 x 2

31/64 (.484)

9/16 (.562)

M14 x 1.5

1/2 (.500)

9/16 (.562)

M16 x 2

9/16 (.562)

41/64 (.640)

M16 x 1.5

37/64 (.578)

41/64 (.640)

M18 x 2.5

5/8 (.625)

23/32 (.718)

M18 x 1.5

21/32 (.656)

23/32 (.718)

M20 x 2.5

45/64 (.703)

13/16 (.812)

M20 x 1.5

47/64 (.734)

13/16 (.812)

Outside Diameter of Screws in Inches

MM

Inches

 

MM

Inches

 

MM

Inches

1.6

.063

 

6.0

.236

 

19

.748

1.8

.071

 

7.0

.275

 

20

.787

2.0

.078

 

8.0

.315

 

21

.827

3.0

.118

 

10.0

.394

 

22

.866

3.5

.138

 

12

.472

 

 

 

4.0

.157

 

14

.551

 

 

 

4.5

.177

 

16

.630

 

 

 

5.0

.197

 

18

.708

 

 

 

Minimum Strengths

METRIC
(ISO 898)		   INCH
(SAE J429)
 No Marking Grade 4, 8 Minimum Strengths =  No Marking Grade 2 Minimum Strengths

Grade 4, 8 (4.6, 5.8)
Tensile: 429 MPa
(60,900 psi)

 

Grade 2
Tensile: 60,000 psi
 
Grade 8.8 Minimum Strengths = Grade 5 Minimum Strengths

 Grade 8.8
Tensile: 830 MPa
(120,350 psi)

 

Grade 5
Tensile: 120,000 psi
 
5-grade-10-9-th = Grade 8 Minimum Strengths

Grade 10.9
Tensile: 1040 MPa
(150,800 psi)

Grade 8
Tensile: 150,000 psi
 
Grade 12.9 Minimum Strengths = Grade ASTM-A574 Minimum Strengths

 Grade 12.9
Tensile: 1220 MPa
(176,900 psi)

Grade ASTM-A574
Tensile: 170,000 psi
Note: Generally
not marked 

 Size – Nominal Diameter     

     Pitch 

     Tap Drill 

 M 1.60

0.35 

1.25 

 M 2.00

.04 

1.6 

 M 2.50

0.45 

2 

 M 3.00

0.5 

2.5 

 M 3.50

0.6 

2.9 

 M 4.00

0.7 

3.3 

 M 5.00

0.8 

4.2 

 M 6.00

1 

5 

 M 8.00

1.25 

6.8 

 M 10.00

1.5 

8.5 

 M 12.00

1.75 

10.2 

 M 14.00

2 

12 

 M 16.00

2 

14 

 M 20.00

2.5 

17.5 

 M 22.00

2.5 

19.5 

 M 24.00

3 

21 

 M 27.00

3 

24 

 M 30.00

3.5 

26.5 

 M 36.00

4 

32 

 M 42.00

4.5 

37.5 

 M 48.00

5 

43 

 M 56.00

5.5 

50.5 

 M 64.00

6 

58 

 M 68.00

6 

62