Value Collection JY4874178 Hand Tap 1-1/2-18 Unef Plug Hss

Product Description

The VALUE COLLECTION JY4874178 is a straight-flute hand tap designed for cutting 1-1/2-18 UNEF internal threads in a range of materials. Machined from high speed steel (HSS) with a bright, uncoated finish, this tap delivers reliable cutting performance in production and maintenance threading operations. It features a plug chamfer, which provides a moderate lead-in of approximately 3 to 5 threads, making it suitable for through-holes and sufficiently deep blind holes. The 6-flute configuration distributes cutting load evenly and supports accurate thread form. Overall length is 4 inches. Thread direction is right hand, and the class of fit is 3B with an H4 thread limit.

This tap is used wherever a 1-1/2-18 UNEF thread must be cut by hand or with a low-speed machine setup. UNEF (Unified National Extra Fine) thread forms are common in precision mechanical assemblies, hydraulic fittings, thin-wall tubing connections, and instrumentation work. It is appropriate for job shop, maintenance, and tool-room use in both commercial and industrial settings. Machinists, millwrights, and precision maintenance technicians are the primary installers and users of this tap.

Key Features

• 1-1/2-18 UNEF thread form for extra-fine pitch threading applications
• Plug chamfer with 3 to 5 thread lead-in for use in through-holes and deep blind holes
• 6-flute straight-flute geometry distributes cutting forces and promotes thread accuracy
• High speed steel construction provides durability across a wide range of workpiece materials
• Bright uncoated finish allows visual wear monitoring during service life
• Class 3B fit with H4 thread limit ensures tight tolerance thread production

Compatibility

Designed as an OEM-style hand tap for cutting 1-1/2-18 UNEF right-hand internal threads in standard threading applications requiring a 3B class of fit.

Installation Notes

This tap is installed and driven by a machinist or maintenance technician using a standard tap wrench or low-speed tapping setup. Always ensure the workpiece is securely fixtured and the tap is properly aligned with the pilot hole before beginning. Apply appropriate cutting fluid for the workpiece material to reduce friction and extend tool life. Do not reverse the tap under load without breaking the chip first, and remove chips regularly to prevent tap breakage in blind-hole applications.