Sumitomo U101186 1/2 in Solid Carbide Screw Machine Drill Bit

Product Description

The SUMITOMO U101186 is a solid carbide screw machine length drill bit designed for high-performance drilling in ferrous and hard materials. Built in the MDW-HGS series, it features a 1/2 inch diameter (0.5000 inches), a 135-degree split point for accurate self-centering, and coolant-through capability to manage heat during demanding cuts. The 2-flute, tapered-web geometry promotes chip evacuation and reduces walking on entry. With an overall length of 5.0394 inches and a flute length of 2.5591 inches, this bit suits production environments where rigidity and hole quality are critical. Installation is performed by machinists, toolroom technicians, and CNC operators.

This drill bit is suited for use in screw machine, CNC turning center, and machining center applications. Primary workpiece materials include cast iron, stainless steel, and steel. The screw machine length (stub) profile keeps overhang short, improving stiffness and dimensional accuracy in close-tolerance bores. The straight-cylindrical shank with a 0.5156-inch shank diameter seats securely in standard ER or Weldon-style toolholders. The h8 diameter tolerance ensures consistent fit across collet systems. The 3xD flute-to-diameter ratio supports drilling to a maximum depth of 1.8090 inches per pass without tool change.

Key Features

• Solid carbide construction for rigidity and wear resistance in hard and abrasive workpiece materials
• 135-degree point angle with tapered web for self-centering entry and reduced thrust
• Coolant-through design delivers cutting fluid directly to the tip for heat management and chip flushing
• 2-flute, 2-margin geometry with 3xD flute ratio supports clean chip evacuation in deep holes
• h8 diameter tolerance on the 1/2 inch cutting diameter ensures consistent collet seating
• Screw machine length profile minimizes overhang for improved hole straightness and surface finish

Compatibility

Designed for use in cast iron, stainless steel, and steel workpieces. The straight-cylindrical shank is compatible with standard ER collet chucks and Weldon-style holders sized for a 0.5156-inch shank diameter. Part of the SUMITOMO MDW-HGS series.

Installation Notes

This tool is installed and operated by machinists or CNC technicians familiar with carbide tooling handling procedures. Ensure the machine spindle is fully stopped and locked out before loading or changing the bit. Secure the shank fully within the toolholder to the manufacturer-specified engagement depth to prevent pullout under cutting load. Solid carbide tooling is brittle and should not be dropped or struck against hard surfaces during handling or setup.