Hertel 66691957 Size 19 Cobalt Screw Machine Drill Bit

Product Description

The HERTEL 66691957 is a screw machine length drill bit designed for high-productivity metal drilling in tight-clearance applications where a standard-length bit will not fit. Built from heavy-duty cobalt steel with a titanium nitride (TiN) coating, it delivers extended tool life when drilling hard and abrasive materials such as stainless steel, cast iron, and high-strength alloys. The 135-degree split point reduces walking and thrust, allowing clean entry without a center punch. Overall length is 2.125 inches, with a flute length of 1.0625 inches, making it compact enough for close-quarter work in machine tool setups and production drilling environments.

This bit is suited for use in screw machines, CNC lathes, drill presses, and hand-held power tools where stub-length tooling is required. The straight-cylindrical shank at 0.1660 inches diameter seats directly in standard drill chucks without adapters. It is sized to wire gauge No. 19, equivalent to 0.1660 inches decimal, and falls within the 0.1500 to 0.2000 inch size range. Machinists, toolmakers, and maintenance mechanics working in metal fabrication and production shops are the primary users of this type of tooling.

Key Features

• Cobalt steel construction for heat and wear resistance in hard-metal drilling
• TiN coating extends cutting edge life and reduces friction
• 135-degree split point reduces thrust and eliminates center-punch requirements
• Web-thinned parallel web for improved chip clearance and cutting efficiency
• Screw machine (stub) length at 2.125 inches OAL for close-quarter and machine tool use
• Heavy-duty grade rating suitable for production and continuous-use drilling

Compatibility

Designed as an OEM-style replacement or direct substitute for screw machine length drill bits in wire gauge No. 19 applications; fits any standard drill chuck accepting a 0.1660-inch straight-cylindrical shank.

Installation Notes

Installation and use of this bit should be performed by machinists or qualified tradespeople familiar with drill press, lathe, or CNC machine operation. Ensure the machine spindle is fully stopped and de-energized before inserting or removing the bit from the chuck. Verify chuck capacity and runout tolerance before securing the shank to avoid tool deflection. Follow applicable shop safety standards and machine guarding requirements during operation.