Hertel 42180 1/8 Inch Cobalt Screw Machine Drill Bit

Product Description

The HERTEL 42180 is a screw machine length cobalt drill bit designed for short-reach drilling in tight workspaces and machine tool applications. Built from M35 cobalt high-speed steel with a straw oxide finish, it delivers heat resistance and edge retention when drilling through demanding materials. The 135-degree split point reduces walking and requires less thrust to start a hole, making it well suited for production drilling environments. At 1.875 inches overall length with a 0.875 inch flute length, this stub-length geometry provides rigid, chatter-resistant performance in drill presses, CNC machines, and turret lathes. Licensed HVAC, plumbing, and mechanical tradespeople keep cobalt stub drills on hand for stainless steel fastener holes and hard material access work.

This bit is intended for drilling hardened materials, heat-treatable alloy steels, stainless steel, and titanium alloys. The short overall length makes it a practical choice for screw machine operations and lathe work where standard-length bits would flex or deflect. It is also used in general fabrication and service applications where a rigid, high-heat-tolerant bit is required to drill through tough base metals without premature dulling or breakage.

Key Features

• M35 cobalt steel construction resists heat buildup during high-speed drilling in alloy and stainless steel
• 135-degree split point self-centers on contact, reducing the need for a center punch on flat stock
• Straw oxide coating provides light lubricity and surface protection
• Screw machine (stub) length gives rigid, low-deflection performance in power feed applications
• Right-hand cut, regular spiral flute evacuates chips efficiently in through-hole drilling
• Straight shank fits standard 3-jaw drill chucks and collet holders without adapters

Compatibility

Designed as a direct-fit replacement for 1/8 inch screw machine length drill bits in the 0.1000 to 0.1500 inch decimal size range. Fits any standard drill chuck or collet accepting a straight shank bit in this diameter class.

Installation Notes

Cobalt drill bits should be run at speeds appropriate for the workpiece material — reduce surface footage compared to standard HSS bits when drilling stainless or titanium to preserve edge life. Secure the workpiece firmly before drilling to prevent deflection or bit breakage. Use cutting fluid or paste lubricant on stainless and alloy steels to dissipate heat and extend tool life. Inspect the split point for chipping before each use; a damaged point will walk and produce oversized holes.