Sumitomo U101078 Screw Machine Drill Bit 6.63 Mm Carbide

Product Description

The SUMITOMO U101078 is a screw machine length drill bit designed for precision drilling in cast iron and steel. Built from solid carbide, it delivers consistent performance in demanding machining environments. The bit features a 135-degree split point angle that reduces walking and improves hole entry accuracy. With an overall length of 2.874 inches and a straight-cylindrical shank diameter of 0.2812 inches, this bit is sized for standard drill chucks and tool holders. The two-flute, tapered web configuration promotes efficient chip evacuation. Machinists and toolroom technicians use this bit in CNC machining centers, drill presses, and screw machine applications where tight tolerances are required.

This drill bit is suited for production and maintenance machining operations where repeatable hole quality in ferrous materials is the priority. The screw machine length format provides increased rigidity compared to jobber-length bits, making it well suited for short-hole drilling in cast iron and steel workpieces. The MDW-GS series solid carbide construction handles the heat and abrasion common in high-cycle machining. No coolant-through capability means it is intended for use with external coolant or dry cutting where applicable. The 0.2610 decimal inch (6.63 mm) diameter falls within the 0.2500 to 0.3000 inch size range of this series.

Key Features

• Solid carbide construction for hardness and wear resistance in ferrous materials
• 135-degree point angle reduces bit walk and improves entry accuracy
• Screw machine length format provides higher rigidity than jobber-length alternatives
• Straight-cylindrical shank fits standard drill chucks and collet-style tool holders
• Tapered web design promotes chip clearance during drilling cycles
• 2xD flute-to-diameter ratio supports depths up to 0.9077 inches (23.06 mm)

Compatibility

Designed as an OEM-style replacement for screw machine length solid carbide drill bits in the MDW-GS series, compatible with applications drilling cast iron and steel workpieces requiring a 6.63 mm diameter hole.

Installation Notes

Installation and use should be performed by qualified machinists or toolroom technicians familiar with carbide tooling. Secure the shank fully in the chuck or collet before operation and verify runout is within acceptable tolerance for the application. Solid carbide bits are brittle compared to high-speed steel — avoid lateral loading or impact. Inspect the cutting edges for chipping before each use and replace the bit if edge damage is observed.