In addition to standard drilling applications,the revolutionary self-clamping CHAMDRILL mechanism is an excellent solution for special drilling requirements. Pre-thread hole drilling is very popular in many industries. Available are drills designed for M8 to M24 ISO M standard pre-thread holes.

The new DCT drills carry two standard chamfering inserts designated AOMT 060204-45DT IC508, symmetrically mounted and cutting forces are balanced for optimal performance. This feature is essential in through hole applications.

Counter boring may be performed, however it is limited to a 6 mm depth.

Unique Chamfering Inserts
The AOMT 060204-45DT IC508 chamfering inserts were designed for chamfering and counter boring on a wide range of materials with optimal chip formation. The insert has an IC08 submicron substrate and is TiCN +TiN PVD coated.

New CHAMDRILL 6.8 mm Pocket Size 
In order to be able to drill the pre-thread hole for the popular M8 thread size, a new 6.8 mm pocket was designed. This pocket can carry a range of drilling heads from 6.8 to 7.49 mm.

Advantages

• Can be used on a wide range of workpiece materials.
• Can be used for blind, as well as through hole, applications.
• No vibrations during chamfering due to a balanced drill construction.
• 1.5 mm x 45º chamfer is possible when the recommended drilling conditions.
• Provides diametric versatility – CHAMDRILL is capable of using a range of drilling heads on each drill body.

This provides a substantial advantage for users who change drills for the same tap operation. The user can use the same DCT drill for ISO M (coarse pitch thread) and for ISO MF (fine pitch thread).

Machining Recommendations

• Machining recommendations used for the standard CHAMDRILL drills apply also to the new DCT drills for both drilling and chamfering - note that the same conditions may be used for chamfering.
• In counterboring, reduce cutting data by 10%.
• In case of chip formation/evacuation problems please try the following recommendations in the order presented:
    - Reduce cutting data by 10%.
    - Increase internal coolant pressure.
    - Apply a pecking cycle.
• Before clamping a new drilling head, apply some oil in any CHAMDRILL pocket. This will reduce pocket wear and increase the number of indexing cycles.

Applications

• Shallow (up to 6 mm) countersink screw head applications.
• Can be used for both rotating and stationary applications.
• An excellent choice for applications requiring a 45 º chamfer.
• Replaces our special drills that were designed for pre-thread hole applications in order to reduce cost and unnecessary handling.
• DCT (M8-M24)