Sumitomo U101123 Solid Carbide Drill Bit Letter Q 135

Product Description

The SUMITOMO U101123 is a solid carbide mechanics-length drill bit sized at Letter Q (0.3320 decimal inch / 8.43 mm) with a 135-degree split point. It belongs to the MDW-GS4 series and carries a TiAlCr/TiSi dual-layer coating engineered for heat resistance and extended tool life in demanding cutting applications. The tapered web geometry supports self-centering entry and reduces thrust load. Overall length is 3.8583 inches with a flute length of 2.0866 inches and a shank diameter of 0.3594 inches. This bit is built for high-performance production drilling in ferrous and non-ferrous metals and is typically run on CNC machining centers or drill presses by machinists and tooling professionals.

The U101123 is suited for drilling cast iron, stainless steel, carbon and alloy steels, and non-ferrous metals including aluminum and copper alloys. The mechanics-length body provides rigidity for through-hole and blind-hole work in tight-tolerance applications on production floors and job shops. The 135-degree point angle reduces walking on hard materials and enables drilling without a center punch in many setups. Coolant-through capability is not present on this bit, so flood or mist cooling at the spindle is recommended when drilling deep holes in heat-sensitive alloys.

Key Features

• Solid carbide construction for rigidity and wear resistance in hard and abrasive materials
• TiAlCr/TiSi coating provides thermal barrier and reduces built-up edge in stainless steel and cast iron
• 135-degree split point for self-centering entry and reduced thrust
• Tapered web configuration supports chip evacuation and cutting stability
• Mechanics-length body balances reach with stiffness for accurate hole placement
• Compatible with standard drill chucks and collet holders accepting a 0.3594-inch shank

Compatibility

Designed for use in CNC machining centers, drill presses, and manual machines accepting a 0.3594-inch round shank. Suitable for primary workpiece materials coded H, K, M, N, P, and S, covering cast iron, non-ferrous metals, stainless steel, and steel grades.

Installation Notes

This bit is installed and operated by machinists and tooling technicians. Power down and lock out the spindle before inserting or removing the bit from the chuck or collet. Verify shank seating depth and runout with a dial indicator before production runs. Because coolant-through is not available, apply adequate external flood or mist cooling to prevent thermal damage to the coating and workpiece, particularly when drilling stainless steel or cast iron at elevated feed rates.