Sumitomo U103705 Jobber Drill Bit Letter H Solid Carbide

Product Description

The SUMITOMO U103705 is a jobber-length drill bit sized at letter H (0.2660 inches diameter) from the MDW-HGS series. It is manufactured from solid carbide and features a dual coating of TiAlCr and TiSi for extended tool life in demanding metal-cutting applications. The 135-degree split point reduces thrust and helps the bit self-center on entry. With an overall length of 4.2913 inches and a straight-cylindrical shank, this bit is designed for use in CNC machining centers and precision drilling operations. It is installed and operated by machinists and tool-and-die professionals working in production environments.

This drill bit is suited for cutting cast iron, stainless steel, carbon steel, and other ferrous alloys. The 5xD flute-to-diameter ratio provides adequate chip evacuation in deeper hole applications. Coolant-through capability makes it compatible with through-spindle coolant systems, helping to flush chips and manage heat at the cutting edge. The h8 diameter tolerance on the drill body supports close-tolerance hole production. Typical applications include production drilling in aerospace, automotive, and general metalworking shops where tool longevity and hole quality are critical.

Key Features

• Solid carbide construction for rigidity and heat resistance in hard-metal drilling
• TiAlCr and TiSi dual coating for extended wear resistance and thermal protection
• 135-degree drill point angle for reduced entry thrust and self-centering performance
• Coolant-through design compatible with through-spindle coolant delivery systems
• Straight-cylindrical shank with h8 tolerance for consistent runout in standard collets and chucks
• Tapered web configuration supports chip flow in 5xD depth-of-cut applications

Compatibility

Designed for use in CNC machining centers and drill presses equipped with through-spindle coolant and standard collet or chuck toolholding systems accepting a 0.2812-inch shank diameter. Suitable for primary workpiece material codes K, M, P, and S, corresponding to cast iron, stainless steel, steel, and superalloys.

Installation Notes

This bit is installed by qualified machinists in collet chucks or drill chucks rated for the 0.2812-inch shank diameter. Ensure the spindle and coolant system are fully de-energized and depressurized before changing tooling. Verify runout with a dial indicator after seating to maintain hole-diameter tolerance. Do not exceed the recommended depth-of-cut ratio for the series without verifying chip evacuation performance.