Value Collection JY4849204 Straight Flute Tap 1-20 Unef

Product Description

The VALUE COLLECTION JY4849204 is a straight flute tap designed to cut 1-20 UNEF internal threads in metal workpieces. It features 4 straight flutes and a plug chamfer, making it well suited for through-hole threading applications where chip evacuation runs in a conventional direction. Constructed from high-speed steel with a bright, uncoated finish, this tap delivers solid wear resistance across a wide range of ferrous and non-ferrous materials. The H4 thread limit and 3B class of fit make it appropriate for standard-tolerance threaded assemblies requiring reliable engagement. Overall length is 5.125 inches. Right-hand thread direction follows standard installation convention.

This tap is used in machine shop, maintenance, and production environments where 1-20 UNEF threads are specified. UNEF (Unified National Extra Fine) threads are common in thin-walled parts, precision assemblies, and applications requiring fine thread pitch for greater holding strength or fine adjustment. The plug chamfer style allows the tap to start threading after a short lead-in, making it practical for both through holes and deeper blind holes with adequate clearance. Machinists, toolmakers, and maintenance technicians working on 1-inch diameter fastener applications will find this tap a direct fit for standard tapping operations on manual or CNC equipment.

Key Features

• 1-20 UNEF thread size with right-hand thread direction
• 4 straight flutes for conventional chip flow in through-hole applications
• Plug chamfer provides a short lead-in for reliable thread start
• 3B class of fit for standard-tolerance threaded assemblies
• H4 thread limit for controlled oversize tolerance
• High-speed steel construction with bright, uncoated finish

Compatibility

Designed as a standard replacement or production tap for 1-20 UNEF threaded applications in ferrous and non-ferrous workpieces. Verify spindle toolholding and tap drive compatibility with your specific machine setup before installation.

Installation Notes

This tap is installed by machinists or toolmakers using a tap wrench, tapping head, or CNC rigid tapping cycle. Always ensure the workpiece is securely fixtured and the pilot hole diameter matches the recommended tap drill size for 1-20 UNEF before beginning. Apply appropriate cutting fluid to reduce heat and extend tap life. Do not reverse the tap under power without confirming the machine supports synchronized reverse; broken taps in finished bores are difficult to remove.