Hertel 16705030 Drill Bit No. 21 0.1590 in Solid Carbide

Product Description

The HERTEL 16705030 is a screw machine length drill bit ground from solid carbide and sized to wire gauge No. 21, equal to 0.1590 inches decimal. The 135-degree split-point geometry reduces walking on entry and lowers the thrust required to start the cut. At 2-1/8 inches overall length, this stub-length format delivers added rigidity compared to jobber-length bits, making it the right choice when a short, stiff tool is needed to maintain hole location and straightness. The bright uncoated finish keeps the carbide substrate exposed for use across a broad range of work materials. Machinists, tool-room technicians, and CNC operators are the primary users.

This bit is suited for production drilling in materials that demand carbide hardness and wear resistance. Primary workpiece materials listed by the manufacturer include cast iron, nickel alloy, stainless steel, titanium alloy, and tool steel. The slow-spiral flute geometry promotes chip control in these tough, work-hardening materials. The straight cylindrical shank seats directly in standard drill chucks and collet holders used on CNC machining centers, knee mills, and drill presses.

Key Features

• Solid carbide construction for drilling cast iron, nickel alloy, stainless steel, titanium alloy, and tool steel
• 135-degree split-point tip reduces walking and lowers entry thrust
• Slow-spiral, 2-flute geometry promotes chip evacuation in tough work-hardening materials
• Screw machine (stub) length at 2-1/8 inches overall provides increased rigidity over jobber-length bits
• Bright uncoated finish — no coating interference on close-tolerance holes
• Straight cylindrical shank fits standard chucks and collet holders without adapters

Compatibility

Designed as an OEM-style replacement or direct-use solid carbide stub drill for machine tool setups requiring a No. 21 wire-size (0.1590 inch) drill with a straight cylindrical shank.

Installation Notes

Installation is performed by machinists or tool-room technicians in a machine tool environment. Ensure the spindle is fully stopped and the machine is locked out before changing tooling. Seat the shank fully and evenly in the chuck or collet and verify runout before production drilling. Carbide is brittle — avoid side loading, interrupted cuts at high feed rates, or dropping the bit, as chipping or fracture can result.