Sgs 51355 Screw Machine Drill Bit 3/8 in Solid Carbide

Product Description

The SGS 51355 is a screw machine length drill bit designed for precision drilling in demanding metalworking applications. Built from solid carbide and coated with Ti-NAMITE-A AlTiN finish, it delivers high heat resistance and extended tool life in hard and abrasive materials. The bit features a 145-degree notched point angle with web thinning for fast penetration and reduced thrust. With a 3/8 inch (0.3750 inch) diameter, a 3-1/2 inch overall length, and a regular spiral flute configuration, it is sized for screw machine and close-tolerance work where a jobber-length bit would be too long. Machinists and toolroom technicians are the primary users.

This drill bit is built for cutting alloy steels and titanium alloys, materials that demand a rigid, wear-resistant carbide tool rather than a high-speed steel alternative. The screw machine length body provides improved rigidity in CNC machining centers, drill presses, and turret lathes where short-reach tooling is required. The straight shank and 0.3750 inch shank diameter allow direct mounting in standard chucks and collets without adapters. The 3xD flute-to-diameter ratio is well suited for through-hole and blind-hole drilling at moderate depths.

Key Features

• Solid carbide construction for high rigidity and wear resistance in hard materials
• AlTiN (Ti-NAMITE-A) coating provides thermal protection and extended cutting life
• 145-degree notched point angle with web thinning reduces entry thrust and improves centering
• Screw machine length (3-1/2 inch OAL) for increased rigidity over jobber-length bits
• Regular spiral flute with 2 flutes and 2 margins for accurate hole geometry
• Right-hand cut, straight shank for direct chuck or collet mounting

Compatibility

Designed for use in CNC machining centers, drill presses, and turret lathes with standard straight-shank collets or chucks accepting a 0.3750 inch shank. Rated for primary workpiece materials including alloy steel and titanium. Part of SGS Series 135 screw machine length carbide drill program.

Installation Notes

Installation and tool changes must be performed with the machine powered down and all spindle rotation fully stopped. Ensure the chuck or collet is properly torqued to the tool holder manufacturer specification before operation. Carbide tooling is brittle — avoid lateral loading, interrupted cuts without proper feed rate adjustment, or dropping the bit on hard surfaces. Follow applicable machine shop safety standards and the equipment manufacturer guidelines for feeds and speeds when cutting titanium and alloy steels.