Sandvik Coromant 7781839 Carbide Drill Bit 7mm 140

Product Description

The SANDVIK COROMANT 7781839 is a solid carbide jobber-length drill bit engineered for high-performance drilling in demanding production environments. Sized at 7 mm (0.2756 inches) in diameter, it features a 140-degree drill point angle and a dual-layer TiAlSiN/TiSiN coating that resists heat and extends tool life at elevated cutting speeds. The straight-cylindrical shank measures 8 mm (0.3150 inches) in diameter and seats securely in standard chucks and collets. With a 2-flute right-hand spiral design and through-coolant capability, this bit maintains chip evacuation and thermal control during deep-hole operations. It is installed by machinists and CNC operators in metalworking and manufacturing applications.

This drill bit is designed for use across a broad range of workpiece materials, including steel, stainless steel, cast iron, non-ferrous metals, superalloys, titanium, and hard materials. It carries ISO material group codes P, M, K, N, S, and H, making it suitable for both general production drilling and high-demand aerospace or automotive machining. The 10xD flute-to-diameter ratio supports deeper penetration without sacrificing rigidity. The overall length of 126 mm (4.9606 inches) and a maximum drilling depth of 57.30 mm (3.3071 inches) fit standard machining center setups.

Key Features

• Solid carbide construction in Series 860-GM for rigidity and wear resistance in hard and abrasive materials
• TiAlSiN/TiSiN dual-layer coating extends tool life and supports high cutting speeds
• 140-degree drill point angle reduces thrust force and improves centering on entry
• Through-coolant capability supports chip flushing and heat reduction in deep-hole drilling
• 10xD flute-by-diameter ratio allows drilling to a maximum depth of 57.30 mm (3.3071 inches)
• Straight-cylindrical shank conforms to DIN 6535HA specification for precise tool holding

Compatibility

Designed for use with standard drill chucks, collets, and hydraulic toolholders that accept an 8 mm straight-cylindrical shank per DIN 6535HA. Suitable for ISO material groups P, M, K, N, S, and H as specified in the product data.

Installation Notes

Installation and tool changes should be performed by qualified machinists with the machine spindle fully stopped and the machine in a safe, de-energized state. Verify that the toolholder bore and shank are clean and free of chips before seating the bit. Through-coolant lines should be confirmed clear and at the correct pressure for the application before commencing drilling. Follow the machine manufacturer and tool manufacturer guidelines for speed and feed selection based on workpiece material.