Dohre Interal Cooling 2 Flutes High Speed Drills

This internal coolant solid carbide drill is designed for high-efficiency deep hole drilling and demanding cutting conditions.

With precision substrate material, self-developed high-performance coating, optimized chip-splitting geometry, and internal coolant design, it delivers excellent tool life, stable cutting performance, and reliable chip evacuation.

Ideal for deep hole machining, high-speed cutting, and difficult-to-machine materials.

1. Premium Carbide Substrate

• Made from imported MG-grade carbide rods

• Ultra-fine grain size: 0.8μm

• 10% cobalt content for balanced toughness and wear resistance

• Excellent adaptability to high-speed and high-feed drilling

This substrate ensures strong edge stability while maintaining sharpness during long cutting cycles.

2.Self-Developed High-Performance Coating

(Benchmarking B-a-l-z-a-s DR Coating)

• Proprietary coating independently developed in-house

• After edge passivation post-treatment

• Coating hardness: 2000–4000 HV

• Ultra-low friction coefficient: 0.05–0.15

• Significantly reduces:

       • Tool wear

       • Edge chipping

       • Adhesion and scratching

The coating effectively extends tool life and ensures stable performance in continuous deep hole drilling.

3. Optimized Drill Geometry Design

Advanced Point & Cutting Edge Design

• Helix angle: 30°

• Point angle: 138.9°

• Double cutting lip design:

      • Primary cutting edge ensures cutting efficiency

      • Secondary cutting edge improves wear resistance and chip breaking

• Equalized web design with angular offset

      • Forms a chip-splitting point structure

      • Prevents drill wandering

      • Enables fast material engagement and stable positioning

This geometry allows smooth cutting and precise hole accuracy even in deep drilling applications.

4. High-Efficiency Flute & Core Design

• Large rake angle: 16°

• Negative chamfer: -6°

• Variable core thickness: 30–40%

• Variable outer diameter: 0.8°

This flute structure significantly improves:

• Chip evacuation

• Cutting stability

• Tool rigidity during deep hole drilling

5. Wide Application Range

Suitable for machining:

• Mild steel

• Quenched & tempered steel

• Quenched & tempered stainless steel

• Cast iron

• Bearing steel

• Deep hole drilling applications

Technical  Comarison

How to Choose the Right Drill?

✔ Choose an Internal Coolant Drill when:

• Drilling depth is ≥ 5×D

• Machining stainless steel or alloy steel

• High requirements for tool life and hole accuracy

• High-speed, continuous CNC production

✔ Choose an External Coolant Drill when:

• Drilling depth is ≤ 3×D

• Machining aluminum or mild steel

• Machine does not support internal coolant

• Cost-sensitive applications

Precision Edge Preparation Technology

To ensure both sharpness and edge strength, every drill undergoes a carefully controlled edge preparation process designed to extend tool life while maintaining stable cutting performance.

• Drill tips are manually edge-honed and chamfered to enhance edge strength and reduce micro-chipping during drilling

• Final edge preparation is completed using a fully automatic passivation system

• Rubber-bonded diamond abrasive polishing process ensures uniform edge quality across all tools

• Edge preparation consistency is guaranteed, with passivation tolerance controlled within ±0.003 mm

• Optimized edge radius improves:

• Wear resistance

• Cutting stability

• Tool life in continuous and deep hole drilling

This combination of manual precision and automated consistency ensures every cutting edge performs reliably under demanding machining conditions.

Strict Quality Inspection & Control

From raw material to finished drill, every production step is monitored under a strict quality control system to guarantee dimensional accuracy, coating performance, and cutting reliability.

• Profile and geometry inspection carried out using WALTER HELICHECK PLUS (Germany)

• Drill profile accuracy and corner radius controlled within 3 μm

• 100% visual inspection at 300× magnification

       • No edge chipping

       • No serrations

       • No surface defects

• In-house coating equipment ensures full control over:

       • Coating thickness consistency

          • Adhesion strength

        • Coating repeatability

        • Coating and edge preparation processes are tightly integrated to guarantee stable quality across different batches

By combining advanced inspection equipment, self-developed coating technology, and in-house coating machines, we ensure every drill meets high-performance industrial standards before delivery.

Q1: What is the advantage of an internal coolant drill compared to an external coolant drill?

A:Internal coolant drills deliver coolant directly to the cutting edge through internal channels, significantly improving chip evacuation and cooling efficiency. This results in better cutting stability, longer tool life, and superior performance in deep hole drilling compared to external coolant drills.

Q2: What drilling depth is recommended for this internal coolant drill?

A:This drill is suitable for 5×D, 8×D, 12×D, and can be customized up to 30×D, making it ideal for deep hole drilling applications where chip evacuation and heat control are critical.

Q3: What coating is used on this drill?

A:The drill features a self-developed high-performance coating, benchmarked against B-a-l-z-a-s DR coating. The coating hardness reaches 2000–4000 HV, with a low friction coefficient of 0.05–0.15, effectively reducing wear and extending tool life.

Q4: Can you provide customized drills?

A:Yes. We support OEM and custom solutions, including customized diameters, drilling depths, point geometries, coatings, and special applications based on customer requirements.

Q5: Can this drill replace well-known international brands?

A:Yes. This drill is designed to achieve 1:1 performance replacement other brand, offering comparable performance with more flexible customization and cost advantages.

Looking for internal coolant drill for deep hole machining?

Contact us now for tool selection advice, custom solutions, and quotations.