材     質

鑽孔徑

規 格(牙徑x 全長)

低碳鋼

6.3mm

1/4

 x

2”

x

3”

7.9mm

5/16

x

2-1/2”

x

3”

9.5mm

3/8

x

2-1/2”

x

3”

x

3-1/2”

x

4”

12.7mm

1/2

x

3”

x

3-1/2”

x

4”

15.8mm

5/8

x

4”

x

5”