1. Product Specifications

This document details technical specifications for twist drills with internal coolant designed specifically for steel drilling. Drill diameters (Dc) range from 1.00 mm to 20.00 mm, with precision tolerance classes m7 or h7. Length parameters L1 (overall length) and L2 (cutting length) vary according to drill size and series, with L1 ranging from 55 mm to over 230 mm and L2 from 15 mm to over 190 mm. Shank diameters (D2) correspond to drill sizes, ranging from 3 mm to 20 mm. Each drill size and specification is identified by a unique code for ordering and traceability.

2. Drill Series and Variants

The drills are organized into series based on length multiples of the diameter (XD):

• 178 3XD Series: Standard length drills (~3 times diameter).
• 178 5XD Series: Longer drills (~5 times diameter) for deeper holes.
• 178 8XD Series: Extra-long drills (~8 times diameter) for very deep drilling.
• 178 12XD Series: Ultra-long drills (~12 times diameter) for specialized deep drilling applications.

3. Material and Standards

The drills are manufactured from micrograin carbide (HM) grades K20-K40, providing high hardness and wear resistance suitable for steel machining. They conform to DIN 6527 standards, which specify dimensions and tolerances for twist drills with internal coolant channels. The geometry includes a 30° helix angle and a 140° point angle (HA), optimized for efficient steel drilling and chip evacuation.

4. Key Parameters and Dimensions

Critical dimensions listed in the specification tables include:

• Dc: Drill diameter in millimeters.
• Diameter Tolerance: m7 or h7 tolerance classes ensuring precision fit.
• L2: Cutting length or flute length.
• L1: Overall drill length.
• D2: Shank diameter matching drill size.

These parameters enable precise selection of drills based on application requirements.

5. Application and Usage Recommendations

• Designed specifically for steel drilling with internal coolant channels to enhance cooling and chip removal.
• Selection of drill length series (3XD to 12XD) depends on required hole depth.
• Precision tolerance classes (m7, h7) ensure compatibility with high-accuracy machining.
• Micrograin carbide material ensures durability and performance in demanding steel drilling operations.

6. Summary of Critical Information

• Drill diameters from 1.00 mm to 20.00 mm with precise tolerances.
• Multiple length options (3XD to 12XD) accommodate various drilling depths.
• Manufactured to DIN 6527 standard with micrograin carbide for steel drilling.
• Internal coolant design improves drilling efficiency and tool life.

This comprehensive technical data supports the selection of appropriate twist drills based on diameter, length, tolerance, and application needs, ensuring compliance with industry standards and optimized machining performance.