Value Collection MSC-04619227 Spiral Flute Tap 1/4-20 Unc

Product Description

The VALUE COLLECTION MSC-04619227 is a spiral flute bottoming tap designed for cutting internal threads in blind and through holes where full thread depth close to the bottom is required. Manufactured from high-speed steel (HSS) with a bright/uncoated finish, this tap features a 45-degree helix angle and three right-hand spiral flutes that efficiently evacuate chips upward out of the hole. It is sized for 1/4-20 UNC threads and conforms to a 3B class of fit with an H3 thread limit, making it suitable for standard-tolerance threaded fastener applications in metal fabrication, maintenance, and repair work. Overall length is 2.5 inches.

This tap is used in general machining, tool-and-die, MRO, and production environments where 1/4-20 UNC internal threads are required. The bottoming chamfer style allows threading to within one to two threads of the bottom of a blind hole, making it the correct choice when a plug or taper tap cannot reach the required thread depth. It is typically installed by machinists, toolmakers, and maintenance mechanics using a tap wrench, tapping head, or CNC machine spindle.

Key Features

• Bottoming chamfer for threading close to the bottom of blind holes
• 45-degree helix angle promotes efficient upward chip evacuation
• High-speed steel construction provides hardness and wear resistance for ferrous and non-ferrous materials
• H3 thread limit with 3B class of fit for standard-tolerance 1/4-20 UNC threads
• Right-hand flute direction and right-hand thread for conventional tapping operations
• Bright/uncoated finish suitable for use with cutting fluid or tapping compound

Compatibility

Designed as a standard replacement or supplemental tap for any application requiring 1/4-20 UNC bottoming threads with an H3 thread limit and 3B class of fit in production or MRO settings.

Installation Notes

Tapping operations should be performed by a qualified machinist or maintenance mechanic following standard tapping procedures. Ensure the workpiece is securely clamped and the tap is properly aligned before starting. Always apply an appropriate cutting fluid or tapping compound to extend tap life and improve thread quality. For blind holes, confirm hole depth allows for the chamfer length before tapping to avoid bottoming out the shank against the workpiece.