Sumitomo U103725 Jobber Drill Bit Letter U Solid Carbide

Product Description

The SUMITOMO U103725 is a jobber-length drill bit sized to letter U (0.3680 inches) with a 135-degree split-point tip. Constructed from solid carbide and finished with a dual TiAlCr/TiSi coating, this bit is built for high-performance metal cutting in demanding production environments. The straight-cylindrical shank measures 0.3906 inches in diameter and accepts standard drill chucks. Overall length is 5.3543 inches with a 2.9921-inch flute length, placing this in a 5xD flute-to-diameter ratio. It is part of the MDW-HGS series and is installed by machinists and toolroom technicians running CNC or manual drilling operations on ferrous and specialty metals.

This drill bit is rated for cutting cast iron, stainless steel, carbon steel, and high-temperature alloys, corresponding to ISO material codes K, M, P, and S. The coolant-through design delivers cutting fluid directly to the tip, making it well suited for deep-hole applications and high-feed cycles where heat management is critical. The tapered web configuration aids chip evacuation and reduces thrust load. Typical use cases include production drilling on machining centers and drill presses in metalworking shops and manufacturing facilities.

Key Features

• Solid carbide construction for rigidity and wear resistance in hard metal applications
• Dual TiAlCr and TiSi coating for heat resistance and extended tool life
• 135-degree split-point tip reduces walking and lowers thrust at entry
• Coolant-through channels deliver fluid directly to the cutting edge
• Tapered web design promotes efficient chip evacuation
• h8 diameter tolerance on the drill tip ensures precise hole sizing

Compatibility

Designed for use in CNC machining centers and manual drill presses capable of accepting a straight-cylindrical shank with a 0.3906-inch diameter; rated for cast iron, stainless steel, steel, and high-temperature alloy workpieces per ISO material codes K, M, P, and S.

Installation Notes

Installation is performed by qualified machinists or toolroom technicians. Secure the straight-cylindrical shank firmly in a compatible drill chuck or collet before operation and verify runout before beginning a cut. Enable coolant-through supply before engaging the spindle to protect the cutting edge and manage chip load. Follow machine manufacturer guidelines for spindle speed and feed rate when drilling hard or abrasive materials.