Sgs 56021 Straight-flute Carbide Drill Bit No. 21

Product Description

The SGS 56021 is a straight-flute carbide drill bit designed for precision drilling in ferrous metals and hardened materials. Built to Series 106 standards and conforming to DIN 6539, this bit features a micrograin carbide construction that holds a sharp edge under the heat and stress of machining cast iron, hardened steel, and general steel stock. The 140-degree point angle promotes accurate entry and reduces walking without a center punch. With a web-thinned geometry and right-hand cutting direction, it is suited for production and maintenance machining environments where tool life and hole quality matter.

This drill bit is intended for use in CNC machining centers, drill presses, and hand-fed drilling operations where a straight-flute geometry is preferred over a spiral-flute design. Straight-flute bits are commonly selected when drilling brittle materials such as cast iron, where chip control and reduced lateral cutting forces are priorities. The No. 21 wire gauge size at 0.1590 inches diameter fills a common requirement in precision hole layouts and tapped hole preparation. This bit is packaged individually and is a fit for tool crib stocking or single-job procurement.

Key Features

• Micrograin carbide construction for extended tool life in ferrous and hardened materials
• 140-degree standard point angle for clean entry and reduced drill walk
• Web-thinned design reduces thrust force during drilling
• Straight-flute geometry optimized for brittle materials such as cast iron
• Right-hand cutting direction, compatible with standard drill spindles
• Conforms to DIN 6539 dimensional standards

Compatibility

Designed for drilling cast iron, hardened steel, and steel workpieces. Primary workpiece materials listed by the manufacturer include cast iron, hardened steel, and steel; secondary materials include hardened materials generally.

Installation Notes

Installation and use of this drill bit should be performed by a qualified machinist or tooling technician familiar with carbide tooling handling and speeds-and-feeds selection. Secure the shank fully in the chuck or collet before operation and verify runout is within acceptable tolerance for the application. Carbide is brittle — avoid side loading, interrupted cuts without proper setup, or dropping the bit on hard surfaces. Power down and de-energize the machine spindle before changing tooling.