Value Collection JY9039678 Straight Flute Tap 1-3/8-8 Un

Product Description

The VALUE COLLECTION JY9039678 is a straight flute tap designed to cut 1-3/8-8 UN-8 internal threads in metalworking and machining applications. Built from high-speed steel (HSS) with a bright uncoated finish, this tap delivers reliable performance across a range of machinable materials. The plug chamfer — typically 3 to 5 threads — makes it suited for through-hole tapping where the chamfer can clear the workpiece. With 4 flutes and a left-hand thread direction, this tap produces left-hand threaded holes, an important distinction when thread direction matters for the application. The H4 thread limit ensures controlled tolerance for standard UN-8 thread fits.

This tap is used in machine shop and maintenance environments where left-hand UN-8 threads are required. It is appropriate for use in manual tapping machines, CNC machining centers, or drill press setups depending on workpiece requirements. At 6-1/16 inches overall length with a 3-inch thread length, it handles moderate-depth through-hole work in ferrous and non-ferrous metals. Machinists, toolmakers, and maintenance technicians working with 1-3/8-inch fastener or fitting applications requiring reverse-thread engagement are the primary users of this tool.

Key Features

• Left-hand thread direction for applications requiring reverse-thread holes
• Plug chamfer (3-5 thread lead) optimized for through-hole tapping operations
• High-speed steel construction provides hardness and wear resistance across common machinable metals
• 4-flute design balances chip clearance and thread form stability
• H4 thread limit for controlled tolerance fit in UN-8 thread class applications
• Bright uncoated finish suitable for general-purpose use without added coating cost

Compatibility

Designed to cut 1-3/8-8 UN-8 left-hand internal threads. Compatible with standard tap holders and collets sized for the corresponding shank diameter in manual or CNC tapping setups.

Installation Notes

This tap should be installed by a qualified machinist familiar with tapping speeds, feeds, and cutting fluid requirements for the workpiece material. Ensure the tapping machine or CNC spindle is set for left-hand rotation before use — running this tap in standard right-hand rotation will damage the tool and the workpiece. Use appropriate cutting fluid to extend tool life and maintain thread quality. Inspect the tap and holder for runout before beginning each operation.