Sgs 51511 Jobber Length Drill Bit 1/4 Inch Carbide

Product Description

The SGS 51511 is a solid carbide jobber-length drill bit designed for high-performance drilling in demanding materials. Built from micrograin solid carbide and coated with an AlTiN (Ti-NAMITE-A) finish, this bit handles steel, stainless steel, and high-temperature alloys where standard high-speed steel tooling falls short. It features a 145-degree split point angle for accurate entry and reduced walking, a web-thinned tip to lower thrust requirements, and a two-flute regular spiral configuration. The straight shank measures 0.2500 inches in diameter, making it compatible with standard chucks. Licensed machinists, tool-and-die tradespeople, and precision metalworking professionals are the primary users.

This bit is sized at 1/4 inch (0.2500 inch decimal, 6.35 mm) and carries a drill bit size letter designation of E. It is suited for production and maintenance drilling operations in steel and stainless steel components, as well as high-temperature alloy parts found in aerospace and industrial fabrication environments. The Series 135L designation places it in a high-performance jobber-length class with a 5xD flute-to-diameter ratio, supporting deeper holes relative to bit diameter while maintaining chip evacuation efficiency.

Key Features

• Micrograin solid carbide construction provides rigidity and wear resistance in hard and abrasive workpiece materials
• AlTiN coating (Ti-NAMITE-A) reduces heat buildup and extends tool life when drilling steel, stainless steel, and high-temp alloys
• 145-degree drill point angle with web-thinned, tapered web geometry improves centering accuracy and reduces entry thrust
• Right-hand cut, regular spiral flute design promotes consistent chip evacuation in through-hole and blind-hole applications
• Straight shank at 0.2500 inches diameter fits standard drill chucks and collet holders without adapters
• Series 135L high-performance grade rated for centering and precision drilling tasks in metalworking

Compatibility

Designed for use in standard drill chucks and collet systems accepting a 1/4 inch straight shank. Primary workpiece materials are steel, stainless steel, and high-temperature alloys. Not rated for coolant-through applications.

Installation Notes

Installation and use should be performed by qualified machinists or metalworking tradespeople familiar with carbide tooling. Secure the shank fully in the chuck or collet before operation to prevent runout and premature edge chipping. Carbide is brittle compared to high-speed steel — avoid side loading, interrupted cuts without proper setup, or using the bit as a reamer. Follow equipment manufacturer guidelines for spindle speed and feed rate appropriate to the workpiece material and drill diameter.