HSS Center Drills

Center drills are used with the lathe to drill a hole in the end of stock for mounting between centers in the lathe. 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. Center drill are also used extensively with the milling machine to accurately start holes. The hole locations can be dialed in using the milling machine's calibrated hand wheels, then the hole is started using the center drill. The large diameter shank on the center drill holds the drill point right on center, Once the hole is started, the center drill is replaced with a drill of the desired diameter and the hole is finished. 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.

　

We 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.

DIN333 HSS Center Drills 　
Manufacturing process: fully ground
Material: M2  Flutes: straight flutes, spiral flutes
Finish: Bright, TiN
Diameter: 1.00-12.5mm
Type A Type B
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
　

ISO866/ISO2540 HSS Center Drills

Manufacturing process: fully ground
Flute type: N
Material: HSS or HSS-Co
Finish: bright, TiN
Diameter: 1-10mm

TYPE A

TYPE B

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

　

　

ANSI HSS Center Drills

Manufacturing process: fully ground
Flute type: N
Material: HSS or HSS-Co
Finish: bright, TiN
Diameter: 1/32-5/16inch

Plain type-Standard length 　
D Dec. Equiv. Body Diameter FL OAL
1/32 0.0313 1/8 3/79 1 1/8
3/64 0.0469 1/8 3/64 1 1/4
5/64 0.0781 3/16 5/64 1 7/8
7/64 0.1094 1/4 7/64 2
1/8 0.125 5/16 1/8 2 1/8
D Dec. Equiv. Body Diameter FL OAL
3/16 0.1875 7/16 3/16 2 3/4
7/32 0.2188 1/2 7/32 3
1/4 0.25 5/8 1/4 3 1/4
5/16 0.3125 3/4 5/16 3 1/2
　 　 　 　 　
　 　
Plain type-Long length 　
D Dec. Equiv. Body Diameter FL OAL
3/64 0.125 1/8 3/64 3
3/64 0.125 1/8 3/64 4
5/64 0.1875 3/16 5/64 4
5/64 0.1875 3/16 5/64 5
7/64 0.25 1/4 7/64 4
7/64 0.25 1/4 7/64 5
1/8 0.3125 5/16 1/8 4
　 　 　 　
D Dec. Equiv. Body Diameter FL OAL
1/8 0.3125 5/16 1/8 5
1/8 0.3125 5/16 1/8 6
3/16 0.4375 7/16 3/16 5
3/16 0.4375 7/16 3/16 6
7/32 0.5 1/2 7/32 6
7/32 0.5 1/2 7/32 6
1/4 0.625 5/8 1/4 6
5/16 0.75 3/4 5/16 6
　 　

Bell type

　

D Dec. Equiv. Body Diameter FL OAL
3/64 0.125 1/8 3/64 1 1/4
5/64 0.1875 3/16 5/64 1 7/8
7/64 0.25 1/4 7/64 2
1/8 0.3125 5/16 1/8 2 1/8
D Dec. Equiv. Body Diameter FL OAL
3/16 0.4375 7/16 3/16 2 3/4
7/32 0.5 1/2 7/32 3
1/4 0.625 5/8 1/4 3 1/4
5/16 0.75 3/4 5/16 3 1/2

Note: Any other sizes are demanded, please kinly contact with us directly, many thanks!