typeb001009.gif
typeb001008.jpg
typeb001007.jpg
typeb001006.jpg
typeb001005.jpg
typeb001004.jpg
typeb001003.jpg
typeb001002.jpg
typeb001001.jpg

Threads For Self-Tapping Screws Type B                           ANSI B18.6.4

Nominal Size

Threads per Inch

Major Dia.

Minor Dia.

Point Dia

Point Taper Length

Minimum Practical screw Length

Max

Min

Max

Min

Max

Min

Max

Min

90° Heads

Csk Heads

6

20

.139

.132

.104

.099

.095

.089

.100

.075

1/4

9/32

7

19

.154

.147

.115

.109

.105

.099

.105

.079

1/4

5/16

8

18

.166

.159

.122

.116

.112

.106

.111

.083

9/32

11/32

10

16

.189

.182

.141

.135

.130

.123

.125

.094

5/16

3/8

12

14

.215

.208

.164

.157

.152

.145

.143

.107

11/32

7/16

14

14

.246

.237

.192

.185

.179

.171

.143

.107

3/8

1/2

 

Suggest Test Plate Thickness & Hole Sizes for Types AB, B, 25

Nominal Size

Thickness

Hole Size

Gage

Max

Min

Drill Size

Hole Dia.

2-32

18

.0500

.0460

48

.0760

3-28

18

.0500

.0460

46

.0810

4-24

18

.0500

.0460

44

.0860

5-20

18

.0500

.0460

36

.1065

6-20

14

.0770

.0730

32

.1160

7-19

14

.0770

.0730

30

.1285

8-18

14

.1270

.1230

29

.1360

10-16

1/8

.1270

.1230

21

.1590

12-14

1/8

.1270

.1230

3/16

.1875

¼-14

3/16

.1905

.1845

5.5mm

.2165

5/16-12

3/16

.1905

.1845

I

.2720

3/8-12

3/16

.1905

.1845

21/64

.3281