Sumitomo U101071 Solid Carbide Drill Bit 0.25 Inch

Product Description

The SUMITOMO U101071 is a screw machine length drill bit engineered for high-performance drilling in ferrous materials. Built from solid carbide with a coated finish, it delivers the rigidity and wear resistance required when drilling cast iron and steel in production or maintenance environments. The bit features a 135-degree split-point angle for self-centering entry and reduced thrust. At 0.25 inches in diameter and 2.8740 inches overall length, it fits standard drill chucks and CNC machining center spindles. The straight-cylindrical shank and tapered web construction support accurate, repeatable hole positioning. This is a two-flute design rated for the MDW-GS series.

The U101071 is suited for screw machine operations, CNC drilling centers, and manual drill press applications where consistent hole quality in cast iron and steel is required. Screw machine length bits are shorter than jobber-length bits, which improves rigidity and reduces deflection in short-hole applications. Maximum drilling depth is 0.8455 inches, making this bit appropriate for through-holes and shallow blind bores in production settings. Machinists, tool-and-die technicians, and maintenance professionals working with steel and cast iron components are the primary users of this bit.

Key Features

• Solid carbide construction provides hardness and thermal resistance for ferrous material drilling
• 135-degree point angle reduces thrust and enables self-centering starts without a center punch
• Coated finish extends cutting edge life and supports chip evacuation
• Screw machine length body increases rigidity and reduces deflection compared to jobber-length bits
• Tapered web configuration strengthens the core along the flute length
• Straight-cylindrical shank fits standard ER collets and drill chucks without modification

Compatibility

Designed as a direct-fit replacement within the SUMITOMO MDW-GS series for drilling cast iron and steel workpieces. Compatible with CNC machining centers, drill presses, and screw machines accepting a 0.25-inch straight-cylindrical shank with h8 diameter tolerance.

Installation Notes

Installation and tool changes should be performed by qualified machinists or toolroom personnel with the machine in a full stop and lockout state per applicable workplace safety standards. Secure the shank fully within the collet or chuck to the manufacturer-specified engagement depth before operation. Inspect the cutting edges for chipping or wear before each use, as carbide tools can fail without visible warning if run at incorrect feeds or speeds. Do not use this bit on materials outside its rated workpiece category, as solid carbide is brittle and susceptible to fracture under impact or interrupted cuts in incompatible materials.