ZEC TOOLS-HSS Center Drills
1.Center drills are used with the lathe to drill a hole in the end of stock for mounting between centers in the lathe.
2.They are designed to drill a small diameter pilot hole followed by a 60 degree countersink that provides a bearing surface for the 60 degree point of the lathe center.
3.Center drill are also used extensively with the milling machine to accurately start holes.
4.The hole locations can be dialed in using the milling machine's calibrated hand wheels, then the hole is started using the center drill.
5.The large diameter shank on the center drill holds the drill point right on center, 6.Once the hole is started, the center drill is replaced with a drill of the desired diameter and the hole is finished.
7.It is imperative hat a cutting lubricant is used, and the center drill is backed off several times to prevent the tip from twisting off.

Item No:
17HC0001

ZEC TOOLS can make Metric HSS center drills according to DIN333 and fractional center drills according to ANSI. Most of them are made of HSS or HSS-E, few of them are made of carbide for special purpose.

Ød

Ød1

L

I

mm

mm

mm

mm

1,00

3,15

31,50

1,60

1,25

3,15

33,50

1,90

1,60

4,00

37,50

2,40

2,00

5,00

42,00

2,90

2,50

6,30

47,00

3,60

3,15

8,00

52,00

4,40

4,00

10,00

59,00

5,60

5,00

12,50

66,00

6,90

6,30

16,00

74,00

8,60

10,00

25,00

100,00

13,70

12,50

31,50

125,00

17,90

Ød

Ød1

L

L

mm

mm=R0

mm

mm

1,00

3,15

37,50

3,00

1,25

3,15

31,50

3,35

1,60

4,00

37,50

4,25

2,00

5,00

42,00

5,30

2,50

6,30

47,00

6,70

3,15

8,00

52,00

8,50

4,00

10,00

56,00

10,60

5,00

12,50

66,00

13,20

6,30

16,00

74,00

17,00

8,00

20,00

80,00

21,20

10,00

25,00

100,00

31,50

12,50

31,50

125,00

33,50

D

d

FL

OAL

mm

mm

mm

mm

1

3.15

1.3

31.5

1

3.15

1.3

.(100)

1

3.15

1.3

.(150)

1

4

1.3

35.5

1.25

3.15

1.6

31.5

1.25

5

1.6

40

1.6

4

2

35.5

1.6

4

2

.(100)

1.6

4

2

.(150)

1.6

6.3

2

45

2

5

2.5

40

2

5

2.5

.(100)

2

5

2.5

.(150)

2

8

2.5

50

2.5

6.3

3.1

45

2.5

6.3

3.1

.(100)

2.5

6.3

3.1

.(150)

2.5

10

3.1

56

3.15

8

3.9

50

3.15

8

3.9

.(100)

3.15

8

3.9

.(150)

3.15

11.2

3.9

60

4

10

5

56

4

10

5

.(100)

4

10

5

.(150)

4

14

5

65

5

12.5

6.3

63

5

18

6.3

75

6.3

16

0.3

71

6.3

20

8

80

8

20

8

80

8

25

10.1

100

10

25

10.1

100

10

31.5

12.8

125

D

Dec. Equiv.

Body Diameter

FL

OAL

mm

mm

mm

mm

mm

1

4

1.3

35.5

2.12

1.25

5

1.6

40

2.65

1.6

6.3

2

45

3.35

2

8

2.5

50

4.25

2.5

10

3.1

56

5.3

3.15

11.2

3.9

60

6.7

4

14

5

65

8.5

5

18

6.3

75

10.6

6.3

20

81

80

13.2

8

25

0.1

100

17

10

31.5

12.8

125

21.2

Dec. Equiv.

Body Diameter

FL

OAL

D

Dec. Equiv.

Body Diameter

FL

OAL

1/32

0.0313

1/8

3/79

1 1/8

3/16

0.1875

7/16

3/16

2 3/4

3/64

0.0469

1/8

3/64

1 1/4

7/32

0.2188

1/2

7/32

3

5/64

0.0781

3/16

5/64

1 7/8

1/4

0.25

5/8

1/4

3 1/4

7/64

0.1094

1/4

7/64

2

5/16

0.3125

3/4

5/16

3 1/2

1/8

0.125

5/16

1/8

2 1/8

D

Dec. Equiv.

Body Diameter

FL

OAL

D

Dec. Equiv.

Body Diameter

FL

OAL

3/64

0.125

1/8

3/64

3

1/8

0.3125

5/16

1/8

5

3/64

0.125

1/8

3/64

4

1/8

0.3125

5/16

1/8

6

5/64

0.1875

3/16

5/64

4

3/16

0.4375

7/16

3/16

5

5/64

0.1875

3/16

5/64

5

3/16

0.4375

7/16

3/16

6

7/64

0.25

1/4

7/64

4

7/32

0.5

1/2

7/32

6

7/64

0.25

1/4

7/64

5

7/32

0.5

1/2

7/32

6

1/8

0.3125

5/16

1/8

4

1/4

0.625

5/8

1/4

6

5/16

0.75

3/4

5/16

6

D

Dec. Equiv.

Body Diameter

FL

OAL

D

Dec. Equiv.

Body Diameter

FL

OAL

3/64

0.125

1/8

3/64

1 1/4

3/16

0.4375

7/16

3/16

2 3/4

5/64

0.1875

3/16

5/64

1 7/8

7/32

0.5

1/2

7/32

3

7/64

0.25

1/4

7/64

2

1/4

0.625

5/8

1/4

3 1/4

1/8

0.3125

5/16

1/8

2 1/8

5/16

0.75

3/4

5/16

3 1/2