CoroDrill 870 Secure and predictable holemaking process

Designed for the intermediate hole-tolerance area of H9–H10, the CoroDrill® 870 exchangeable-tip drill saves time and reduces your cost per hole.

CoroDrill 870 can be tailored to optimize applications through diameter range, step, and length possibilities. Holes can be made more efficiently and closer to the specifications required, leaving them in better condition for subsequent operations.  

 

 

 

 

News

Introducing
CoroDrill 870 step and chamfer drills as Tailor Made. Step or chamfer holes can be drilled in one operation.

 
 

See more CoroDrill 870 films

 

 

Benefits

The interface between tip and drill is simple, accurate, and stable. Optimized drill flutes facilitate chip evacuation. The tip is changed while still in the holder savinging you valuable cutting time. New cutting edge geometries and grades provide a safe cutting process with optimized chip control, high penetration rates, and a long, dependable tool life.

  • Reliable and secure process
  • Easy handling and secure tip changing
  • Optimized chip control and evacuation
  • Long, predictable tool life and high productivity
  • Low cost per hole and excellent hole quality

 

Features

  • Secure, high-precision interface between drill body and tip for extra stability
  • Change tip while tool is in the machine to reduce downtime
  • Drill flutes with optimized shape, size, and helix angle optimized for safe chip evacuation and overall tool stability
  • Rigid drill body for high penetration rates and excellent hole quality
    Internal coolant for all drills
  • Tailor Made 45-degree chamfer drill for producing chamfered holes in one operation is available.

–PM geometry and GC4234 for steel, –KM geometry and GC3234 for cast iron, and –MM geometry and GC2234 for stainless steel

  • Geometries for high process security, good chip control, high penetration rates, and premium hole quality
  • –KM geometry with chamfered corners for optimized hole quality at exit and increased tool life in cast iron
  • Grades with predictable wear as well as long and reliable tool life at high productivity rates

–GP 4234 pilot geometry

  • Used to make pilot holes prior to drilling with 6 × diameter drills or longer
  • Enables a smooth and secure entry into the pilot hole for the long drill

 

Application

  • Hole tolerance: H9–H10
  • Hole diameter range: 10.00–33.00 mm (0.394–1.299 inch)
  •  Hole depths: up to 10 × drill diameter
  • Typical hole types: pre-holes for taps and bolt holes
ISO application area

 

 

Engineered Solution

If our Tailor Made solution does not meet your needs, an engineered solution is the way to go.

Contact your local Sandvik Coromant representative for more info.

 

Tailor Made step and chamfer drills for producing holes in one operation are available.

 

 

Recommendations

For quick and easy tool mounting, gently press the tip down and towards the support surfaces while tightening the screw to the recommended torque shown on the drill body. Preferably, use a torque screw driver to ensure that the tip is securely seated.

Internal cutting fluid is recommended for safe chip evacuation. Please apply sufficient cutting fluid flow and follow the recommendation on emulsion concentration from the oil supplier.

For optimum stability and minimum run-out, clamp CoroDrill 870 with a CoroChuck™ 930 hydraulic chuck with sealed cylindrical collet.

Note: Never use a CoroChuck™ 930 in combination with an ISO 9766 shank without a cylindrical collet!

 

Cutting data recommendations for CoroDrill 870

 



Recommended drilling strategy for lengths ≥6×DC

1. Use a CoroDrill 870 ≤ 3xDC with -GP
geometry to drill a pilot hole with depth ~0.5xDC
​ ​

 

2. With the ≥ 6×DC drill; enter the pilot hole with recommended cutting speed and feed and continue drilling​ ​

 

 

 

 

 

 

vc= 100% m/min (ft/min)
fn= 100% mm/rev (inch/rev)

Handling instructions

   
Product range

Drill bodies
Diameters with drill tip mounted,
mm (inch)
Shank type ​ Length (×DC)
10.00–33.00 (0.394–1.299) Cylindrical with flat according to ISO 9766
(mm and inch) ​
3, 5, 8​
10.00–26.99 (0.394–1.063) Cylindrical with flat according to ISO 9766
(mm and inch)
10
 Drill tips
Diameters, mm (inch)  Geometry Grade Application
10.00–33.00 (0.394–1.299) -PM​GC4234​
10.00–33.00 (0.394–1.299) -KM​GC3234​
10.00–33.00 (0.394–1.299) -MM​GC2234​
10.00–33.00 (0.394–1.299)​–GP​GC4234​