Milwaukee Tool 49-57-5508 4-40 Nc Tap and Drill Set

Product Description

The MILWAUKEE TOOL 49-57-5508 is a 2-piece tap and drill set designed for threading 4-40 NC fastener holes in metal and other materials. The set includes one 4-40 NC plug tap and one No. 43 drill bit, both manufactured from high carbon steel with an oxide finish for corrosion resistance and extended tool life. The plug tap is a standard hand tap used to cut internal threads in through-holes and blind holes. This set is a task-specific pairing that gives technicians the correct drill size and matching tap in a single package, eliminating the guesswork of selecting compatible tooling.

This set is suited for electricians, HVAC technicians, plumbers, and mechanical tradespeople who regularly thread small-diameter fastener holes in sheet metal, enclosures, brackets, and light structural components. The 4-40 NC thread is a fine-pitch, small-diameter thread common in control panels, electrical enclosures, and equipment housings. The No. 43 drill bit is the correct tap drill for the 4-40 thread, making this set a reliable grab-and-go solution for field and shop use alike.

Key Features

• Includes one 4-40 NC plug tap and one No. 43 drill bit matched as a tap drill pair
• High carbon steel construction on both the tap and drill bit for durability in threading applications
• Oxide coating on the tap provides corrosion resistance and reduces friction during thread cutting
• Standard hand tap design compatible with manual tap handles and standard tapping equipment
• Right-hand thread direction for conventional clockwise threading
• Compact 2-piece set with no case, sized for tool pouch or parts bin storage

Compatibility

Designed for use with standard tap handles and compatible with 4-40 NC threading applications in metal substrates. The No. 43 drill bit is the industry-standard tap drill size for 4-40 NC threads.

Installation Notes

Thread cutting should be performed by a qualified tradesperson familiar with proper tapping technique. Secure the workpiece before drilling and tapping to prevent movement. Apply cutting fluid to the tap during thread cutting to reduce heat buildup and extend tap life. Back the tap out periodically to clear chips, particularly in blind-hole applications.