Sumitomo U101073 Screw Machine Drill Bit 0.25in Carbide

Product Description

The SUMITOMO U101073 is a solid carbide screw machine length drill bit designed for high-performance drilling in ferrous and hard materials. Built to MDW-HGS series specifications, it features a 135-degree split point for accurate starts and reduced thrust, and a straight-cylindrical shank for reliable chuck retention. At 0.25 inches in diameter and 3.4646 inches overall length, this bit handles demanding production environments where short, rigid tooling is required. Coolant-through capability supports high-speed operation and helps manage heat in difficult workpiece materials. Intended for use by machinists and tool-and-die professionals in CNC and manual drilling applications.

This drill bit is rated for cast iron, stainless steel, and steel workpieces. The screw machine length designation indicates a shorter flute-to-shank ratio compared to jobber-length bits, providing added rigidity and reduced deflection in tight setups or multi-spindle machines. A flute-by-diameter ratio of 3xD and a maximum drilling depth of 0.9050 inches make it well suited for shallow, precise bores in production machining environments. The h8 diameter tolerance ensures consistent fit in tight-tolerance boring and reaming sequences.

Key Features

• Solid carbide construction for hardness and wear resistance in ferrous materials
• 135-degree drill point angle reduces walking and lowers entry thrust
• Coolant-through design supports high-speed feeds and extends tool life
• Straight-cylindrical shank compatible with standard drill chucks and collets
• Tapered web configuration adds core strength across flute length
• h8 diameter tolerance for consistent fit in precision machining sequences

Compatibility

Part of the SUMITOMO MDW-HGS series, rated for use in cast iron, stainless steel, and steel workpieces. Drill bit size range for this series is 0.2500 to 0.3000 inches.

Installation Notes

Installation and use should be performed by a qualified machinist familiar with CNC or manual drilling equipment. Ensure the spindle and workpiece are fully secured before operation, and confirm coolant lines are connected and flowing before engaging coolant-through function. Do not exceed manufacturer feed and speed recommendations for the target workpiece material, as solid carbide is brittle and susceptible to breakage under excessive lateral load. Inspect the cutting edge for chipping before each use.