Sumitomo U101032 Screw Machine Drill Bit 0.161 in Carbide

Product Description

The SUMITOMO U101032 is a screw machine length drill bit designed for precision drilling in ferrous materials. Built from solid carbide with a coated finish, it delivers the hardness and wear resistance needed for production-level work in cast iron and steel. The bit measures 0.161 inches (4.09 mm) in diameter with an overall length of 2.4016 inches and features a 135-degree split-point angle that reduces walking and requires no center punch on flat stock. Two flutes with a tapered web configuration promote chip evacuation during short-hole drilling operations. Licensed machinists, tool-and-die shops, and maintenance technicians routinely use this size in CNC machining centers, knee mills, and drill presses.

This bit is suited for screw machine length applications where a stub-length geometry provides rigidity and reduced runout compared to jobber-length equivalents. Primary workpiece materials are cast iron and steel. The flute-to-diameter ratio is 2xD, making it appropriate for through-holes and shallow blind holes up to a maximum drilling depth of 0.664 inches (16.87 mm). The straight-cylindrical shank seats directly in standard collets, keyless chucks, or ER toolholding systems without adapters.

Key Features

• Solid carbide construction for hardness and thermal stability in ferrous materials
• 135-degree drill point angle reduces thrust and eliminates the need for a center punch on flat surfaces
• Coated finish extends tool life in abrasive cast iron and steel applications
• Tapered web configuration supports chip flow and reduces torque load
• Straight-cylindrical shank fits standard collets and chucks without adapters
• 2xD flute-to-diameter ratio optimized for screw machine length short-hole drilling

Compatibility

Designed as a screw machine length replacement drill bit for use in CNC machining centers, drill presses, and manual mills where a straight-cylindrical shank and carbide construction are required for drilling cast iron and steel workpieces.

Installation Notes

Installation and tool changes should be performed by a qualified machinist with the spindle fully stopped and the machine in a locked-out, de-energized state per OSHA lockout/tagout procedures. Confirm the shank is fully seated and the chuck or collet torqued to the toolholder specification before initiating a cut. Carbide tooling is brittle and susceptible to chipping from interrupted cuts or side loading — avoid using this bit as a reamer or applying lateral force. Verify coolant or cutting fluid compatibility with the workpiece material before use, noting that this bit does not support through-spindle coolant.