Sumitomo U101043 Screw Machine Drill Bit 0.1875 in Carbide

Product Description

The SUMITOMO U101043 is a solid carbide screw machine length drill bit designed for high-performance drilling in ferrous and hard-to-machine materials. Part of the MDW-HGS series, it features a 3/16 inch (0.1875 inch) diameter, a 135-degree drill point angle for self-centering starts, and a straight-cylindrical shank for direct chuck or collet mounting. With coolant-through capability and a tapered web configuration, it manages heat and chip evacuation in demanding production drilling environments. The overall length is 3.1496 inches, keeping the tool compact and rigid for stub-length applications. Licensed machinists and tool-room technicians are the primary users of this bit.

The U101043 is suited for drilling cast iron, stainless steel, and steel in production and job-shop machining operations. The screw machine length designation means a shorter flute-to-body ratio compared to jobber-length bits, which reduces deflection and improves hole location accuracy. The 3xD flute-to-diameter ratio and 1.0827 inch flute length accommodate through-holes and blind holes up to a maximum drilling depth of 0.8015 inches in a single pass without pecking. It fits CNC machining centers, drill presses, and manual knee mills where repeatability and tool life on hard materials are priorities.

Key Features

• Solid carbide construction for rigidity and wear resistance in ferrous materials
• 135-degree split point reduces thrust and self-centers on entry without a center punch
• Coolant-through design delivers cutting fluid directly to the cutting edge for heat control
• Tapered web with 2 margins maintains hole geometry and surface finish
• Straight-cylindrical shank compatible with standard drill chucks and collet holders
• Drill bit diameter tolerance h8 ensures consistent fit in precision boring and reaming sequences

Compatibility

Designed for use on cast iron, stainless steel, and carbon steel workpieces. Fits standard straight-shank drill chucks and ER-style collet holders accepting 3/16 inch shanks. Part of the SUMITOMO MDW-HGS series covering the 0.1500 to 0.2000 inch drill bit size range.

Installation Notes

Installation and use should be performed by qualified machinists familiar with cutting tool mounting procedures. Ensure the machine spindle is fully stopped and locked out before changing tooling. Secure the shank fully within the chuck or collet to the recommended engagement depth to prevent pullout under cutting loads. Do not exceed the maximum drilling depth of 0.8015 inches per pass without verifying chip clearance; enable coolant-through flow before engaging the cut when using internal coolant supply.