Sumitomo U101115 Screw Machine Drill Bit 0.323 in Carbide

Product Description

The SUMITOMO U101115 is a solid carbide screw machine length drill bit designed for high-performance drilling in demanding shop and production environments. At 0.323 inches in diameter (Letter size P), it features a 135-degree split point angle and a straight-cylindrical shank that seats securely in standard drill chucks and collets. The two-flute, tapered-web geometry supports chip evacuation and reduces walking at entry. Overall length is 3.228 inches, making it well suited for compact, rigid setups where a jobber-length bit would be excessive. This bit is part of the MDW-GS series and carries an h8 diameter tolerance for consistent fitment in precision drilling applications.

The U101115 is intended for production drilling in cast iron and steel workpieces. Its screw machine length profile — shorter than jobber length — delivers added rigidity and improved straightness in CNC machining centers, manual drill presses, and turret lathes. The 2xD flute-by-diameter ratio and maximum drilling depth of 0.933 inches make it appropriate for shallow-to-moderate depth holes where roundness and hole quality are priorities. Coolant-through is not supported on this bit; external coolant or cutting fluid application is recommended when drilling ferrous materials at production rates.

Key Features

• Solid carbide construction for wear resistance and rigidity in ferrous materials
• 135-degree point angle reduces thrust and minimizes walking on entry
• Tapered web design supports chip flow through the 1.417-inch flute length
• Straight-cylindrical shank with h8 diameter tolerance for repeatable chuck fitment
• Screw machine length body provides added stiffness versus jobber-length alternatives
• MDW-GS series geometry optimized for cast iron and steel drilling

Compatibility

Designed for use in cast iron and steel workpieces. Compatible with standard drill chucks, ER collets, and toolholders accepting a straight-cylindrical shank at the specified diameter. Verify spindle and chuck capacity before installation.

Installation Notes

Installation should be performed by a qualified machinist or tooling technician. Power down and lock out the machine spindle before inserting or removing the bit. Ensure the shank is fully seated and the chuck or collet is tightened to the toolholder manufacturer's specified procedure. Because this bit does not support coolant-through, apply external cutting fluid or coolant at the point of contact when drilling steel or cast iron to manage heat and extend tool life.