MITSUBISHI MATERIALS CORPORATION
BACK


MIRACLE ZET1 Drill
CAUTION FOR USE  
Spot facing as shown above is not possible due to large diameter not having a back taper. Please contact us if spot face drills are required. Chips from the chamfer machining tend to be elongated and may cause jamming. It is recommended to peck feed to reduce the length of chips. Cutting resistance increases on initial contact with chamfer. Reduce feed at this point. The width of the chamfer is C1.0 for M4-M6, and C1.5 for M4-M12.
For width other than those stated above consultation is needed.

DRILL SIZE AND HOLE DIAMETERS FOR TAPPING  
For Metric Coarse Thread
Thread
Size 		Initial Thread Diameter Tolerance MZE / MZS Drill Application Reference
HSS Drill
max min
M2.5 X0.45 2.138 2.013 2.1 2.1
M3 X 0.5 2.599 2.459 2.5 2.5
M3.5 X 0.6 3.010 2.850 2.9 2.9
M4 X 0.7 3.422 3.242 3.4 3.3
M4.5 X 0.75 3.878 3.688 3.8 3.8
M5 X 8 4.334 4.134 4.3 4.2
M6 X 1 5.153 4.917 5.1 5.0
M7 X 1.25 6.153 5.917 6.1 6.0
M8 X 1.25 6.912 6.647 6.8 6.8
M9 X 1.25 7.912 7.647 7.8 7.8
M10 X 1.5 8.676 8.376 8.5 8.5
M11 X 1.5 9.676 9.376 9.5 9.5
M12 X 1.75 10.441 10.106 10.3 10.3
M14 X 2 12.210 11.835 12.0 12.0
M16 X 2 14.210 13.835 14.0 14.0
M18 X 2.5 15.744 15.294 15.5 15.5
M20 X 2.5 17.744 17.294 17.5 17.5
M22 X 2.5 19.744 19.294 19.5 19.5

(Note.)Holes drilled with an MZE type drill should be +0.01 - 0.03mm oversize. For thread tapping and replacement of HSS drills, an approximately 0.1mm bigger drill is recommended.
· Operational guidance
TOP
Drill holding Drill length Drill installation

Drill retention

Thrust bearing type collet chuck holds the drill securely.

Determining drill length

A ≥ D1 x 1.5

Drill insertion

Do not clamp on the flutes.
Installation tolerance Coolant method (MWE) Through coolant type (MWS)

Drill run out at time of insertion

Run-out ≤ 0.03mm

Appropriate coolant lubrication method (MZE type)

Two coolant positions, at the end and at the center are ideal.

 Coolant lubrication method
Coolant pressure is approx. 0.5-1MPa (<ø:2-3MPa). Coolant volume is 1.5-4.0/min.
Drill Installation Coolant handling Thin workpiece

How to use a small diameter drill

(1)When machining a prepared hole with the MZE-SB please set the depth to 1D (D=drill diameter).
(2) Use the prepared hole as a guide when using a drill with an oil hole. Depending on the cutting conditions, pick feed is recommended.

　　　　　　<MWS type>

1) Small particles of swarf will jam in the oil hole of small diameter drills. Always use a fine mesh filter as a preventative measure.

2) Dirt and dust particles adhere to the oil in old coolant and prevent an efficient flow. Regular coolant exchange is recommended.

Thin-plate boring
Interrupted cutting Stepped holes Burring and workpiece chipping
Interrupted cutting Stepped drilling (Joggling)
(1) Divide the two processes.
(2) Drill the larger hole first.
* A tool for machining both chamfer and spot face can be produced to order. 		Burrs and chips at time of full penetration of work piece
(1) Lower the feed rate by 50% at the end of through cutting.
(2) Add a 45°chamfer.
(3) Change the point angle.
· Caution to use MZS type (Drill Diameter ≤ ø3)  
  • Please use a fine mesh filter (mesh≤3µm) for coolant to prevent jamming in the oil hole.
  • For deep drilling (l/d>3), machining a guide hole is recommended. (Use MZEXXXXSB type for guide holes.)
  • Peck drilling is also effective.
· Cutting performance of MIRACLE ZET1 Drill
TOP
  • Mild steel
    Mild steel
  • Carbon steel (JIS S50C)
    Carbon steel (JIS S50C)
· Cutting resistance
TOP
Workpiece: SCM440 (300 HB)  Cutting speed: 50 m/min
Power consumption Torque
Power consumption Torque
Thrust
Thrust
· Internal coolant type  
When using an internal coolant type drill, small particles of swarf will jam in the oil hole. Always use a filter for the coolant.