Sumitomo U101088 Mechanics Drill Bit Letter I Carbide

Product Description

The SUMITOMO U101088 is a solid carbide mechanics drill bit in Letter I size (0.2720 decimal inch / 6.91 mm) with a 135-degree split-point geometry and a TiAlCr/TiSi dual-layer coating. Part of the MDW-GS4 series, it is built for high-performance drilling in demanding production and maintenance environments. The 135-degree point reduces walking on entry and lowers thrust load, while the TiAlCr/TiSi coating provides heat and wear resistance well suited to abrasive and hard workpiece materials. Licensed HVAC, plumbing, electrical, and mechanical tradespeople who drill through structural members, equipment housings, and mounting plates will find this bit reliable in both handheld and machine-mounted applications.

This mechanics-length drill bit is designed for use on cast iron, non-ferrous metals, stainless steel, and carbon and alloy steels. The shorter mechanics-length body provides added rigidity and reduced deflection compared to jobber-length bits, making it well suited for drill press, CNC, or hand-drill work where hole location accuracy and surface finish matter. The tapered web configuration supports chip evacuation and cutting stability across the primary workpiece material range listed.

Key Features

• Solid carbide construction for rigidity and extended tool life in hard and abrasive materials
• TiAlCr/TiSi coating delivers thermal and oxidation resistance at elevated cutting temperatures
• 135-degree split point reduces entry walking and lowers axial thrust force
• Tapered web geometry supports chip flow and cutting stability
• Mechanics length provides a stiffer, more accurate platform than jobber-length alternatives
• Compatible workpiece materials include cast iron, stainless steel, non-ferrous metals, and steel alloys

Compatibility

Designed for use on cast iron, non-ferrous metals, stainless steel, and carbon and alloy steels (workpiece material codes H, K, M, N, P, S). Fits any drill chuck or collet accepting a 0.2812-inch shank diameter.

Installation Notes

Installation and use should be performed by qualified machinists or trade professionals familiar with drill press, CNC, or hand-drill operation. Ensure the workpiece is securely clamped before drilling to prevent rotation or movement. Use appropriate cutting fluid or coolant where the machine setup allows, even though this bit does not have through-coolant capability. Verify chuck or collet runout is within acceptable tolerances before use to avoid premature edge chipping on solid carbide tooling.