Sumitomo U101159 Screw Machine Drill Bit 13/32 Carbide

Product Description

The SUMITOMO U101159 is a screw machine length drill bit designed for high-performance drilling in metalworking applications. Built from solid carbide with a coated finish, it delivers the hardness and wear resistance required for cutting cast iron and steel. The bit features a 135-degree split point, a straight-cylindrical shank, and a tapered web configuration. At 0.4063 inches (13/32 inch) in diameter and 3.6614 inches in overall length, it is sized for compact, rigid setups where shorter flute length improves stability and runout control. Licensed machinists, tool and die technicians, and CNC operators are the primary installers of this bit.

This drill bit is suited for production environments and job shop machining where consistent hole quality in ferrous materials is required. The MDW-GS series screw machine length design reduces overhang and deflection in CNC machining centers, drill presses, and manual lathes. Its 2xD flute-by-diameter ratio and maximum drilling depth of 1.0047 inches make it appropriate for through-hole and blind-hole operations in cast iron and steel workpieces. The h8 diameter tolerance on the shank ensures accurate tool holder fit and reliable repeatability across multiple operations.

Key Features

• Solid carbide construction with coated finish for wear resistance in ferrous materials
• 135-degree drill point angle reduces thrust force and improves self-centering
• Screw machine length body minimizes deflection and improves rigidity in short-reach setups
• Straight-cylindrical shank with h8 tolerance for precise tool holder seating
• Tapered web configuration supports chip evacuation in cast iron and steel drilling
• 2-flute design rated for cast iron and steel primary workpiece materials

Compatibility

Designed as an OEM-style replacement bit within the SUMITOMO MDW-GS series, compatible with standard straight-shank tool holders accepting a 0.4063-inch diameter shank in CNC machining centers and drill presses.

Installation Notes

Installation of carbide drill bits should be performed by a qualified machinist or CNC operator. Ensure the spindle is fully stopped and the machine is locked out before loading or changing tooling. Seat the shank fully into the tool holder collet and torque the retention mechanism per the tool holder manufacturer's specification. Carbide bits are brittle compared to high-speed steel — avoid lateral loading or interrupted cuts that can cause chipping or fracture.