Sumitomo U101029 Screw Machine Drill Bit 0.157in Carbide

Product Description

The SUMITOMO U101029 is a screw machine length drill bit engineered for precision drilling in ferrous materials. Built from solid carbide with a coated finish, it delivers the wear resistance and edge retention required for production drilling in cast iron and steel. The bit features a 135-degree split-point angle that reduces walking and minimizes thrust load at entry. At 0.157 inches (3.99 mm) in diameter with a 2-flute straight-cylindrical shank design, it fits standard drill chucks and collet holders without adapters. The tapered web configuration improves chip evacuation and helps maintain hole quality through the cut. Licensed machinists, tool-and-die makers, and production line maintenance techs are the primary users of this bit.

The U101029 belongs to the MDW-GS series and is sized for screw machine length applications where a shorter, more rigid drill is preferred over jobber or taper length alternatives. It is suited for drilling in cast iron and steel in CNC machining centers, drill presses, and screw machines. The 2xD flute-by-diameter ratio supports drilling depths up to 0.670 inches (17.02 mm) per pass, making it appropriate for shallow to moderate-depth holes in production environments where cycle time and hole-to-hole consistency matter.

Key Features

• Solid carbide construction for extended tool life in cast iron and steel
• 135-degree drill point angle reduces thrust and minimizes drill walk at entry
• Coated finish improves surface hardness and heat resistance
• Straight-cylindrical shank fits standard chucks and collets without adapters
• Tapered web configuration promotes chip evacuation during drilling
• Diameter tolerance class h8 ensures consistent fit and repeatable hole sizing

Compatibility

The U101029 is designed for use in standard drill chucks and collet systems accepting a straight-cylindrical shank. Primary workpiece materials are cast iron and steel. It is sized within the MDW-GS series range of 0.150 to 0.200 inches (3.50 to 5.00 mm) diameter.

Installation Notes

Install and remove drill bits only after the machine spindle has come to a complete stop and the machine is powered down or in a safe lockout state. Secure the shank fully in the chuck or collet to the manufacturer-specified engagement depth before operation. Carbide tooling is brittle — avoid side loading, interrupted cuts without proper feed rate adjustment, or dropping the bit on hard surfaces. Always verify spindle speed and feed rate are appropriate for the workpiece material and bit diameter before starting the cut.