Hertel 66691809 Screw Machine Drill Bit Size 4 Cobalt Tin

Product Description

The HERTEL 66691809 is a screw machine length drill bit designed for high-production drilling in metal fabrication, machining, and maintenance applications. Built from cobalt steel with a titanium nitride (TiN) coating, this bit handles hard and abrasive materials where standard high-speed steel bits wear prematurely. The 135-degree split point starts on contact without center-punching, reducing walking and improving hole location accuracy. At 2.375 inches overall length with a 1.25-inch flute, the stub-length body provides extra rigidity for accurate, chatter-free drilling in a drill press, turret lathe, or CNC setup. The straight cylindrical shank fits standard drill chucks and collets sized for 0.2090-inch shanks.

This bit is suited for drilling mild steel, stainless steel, cast iron, and other hard metals in production shop and field machining environments. The screw machine length profile makes it a first choice when drill press quill travel is limited or when workpiece setup requires a shorter, stiffer tool. Machinists, tool-and-die workers, and maintenance mechanics commonly reach for this type of bit when standard jobber-length bits flex or drift in tough materials.

Key Features

• Cobalt steel construction resists heat buildup in hard and abrasive metals
• TiN coating reduces friction and extends cutting edge life
• 135-degree split point reduces thrust and eliminates center-punch requirement
• Web-thinned, parallel web configuration improves chip evacuation
• Stub screw machine length adds rigidity and reduces deflection
• Right-hand spiral flute with straight cylindrical shank for standard chuck compatibility
• Heavy-duty grade rated for production and repeat-cycle drilling

Compatibility

Designed as a direct-fit replacement for screw machine length drill bits in the wire size 4 (0.2090 inch) range, compatible with any drill press, lathe, or CNC spindle fitted with a chuck or collet accepting a 0.2090-inch straight cylindrical shank.

Installation Notes

Install the shank fully into the chuck or collet and tighten securely before operation. Verify spindle speed is appropriate for the workpiece material and bit diameter per standard machining tables. Coolant through is not supported on this bit, so apply cutting fluid externally when drilling steel or stainless. Inspect the cutting edges for wear or chipping before each use and replace if the point shows heat discoloration or edge rollover.