Value Collection MSC-04919130 Hand Tap 1-12 Unf Left Hand

Product Description

The VALUE COLLECTION MSC-04919130 is a straight-flute hand tap designed for cutting 1-12 UNF left-hand internal threads in metalworking applications. Manufactured from high speed steel with a bright, uncoated finish, this tap delivers reliable thread-cutting performance without additional surface treatment. It features a taper chamfer for progressive thread engagement, a 4-flute straight-flute geometry suited to through-hole and shorter blind-hole tapping, and meets a Class 3B fit with an H4 thread limit for close-tolerance work. Overall length is 5.125 inches with a thread length of 2.5 inches. It is installed by hand using a tap wrench and is appropriate for machinists, maintenance technicians, and tool-and-die professionals.

This tap is suited for creating left-hand internal threads in ferrous and non-ferrous metals where reverse-thread fastener assemblies or left-hand screw applications are required. The 1-12 UNF thread form is a fine-pitch unified national fine standard commonly found in precision mechanical and aerospace-adjacent assemblies. The taper chamfer distributes cutting load across the first several threads, making it practical for hand-tapping operations where controlled torque application is critical. It is a single-piece unit packaged and sold individually.

Key Features

• Left-hand thread direction for reverse-thread and specialty fastener applications
• High speed steel construction provides durability across a broad range of workpiece materials
• Taper chamfer distributes cutting load gradually for smoother hand-tapping entry
• 4-flute straight-flute design supports chip evacuation in through-hole and shallow blind-hole work
• Class 3B fit with H4 thread limit for close-tolerance, high-precision thread requirements
• Bright, uncoated finish — no coating buildup to affect thread tolerance

Compatibility

Designed as a standard hand tap for use in any tap wrench or tapping fixture that accepts the appropriate shank size; suited for cutting 1-12 UNF left-hand internal threads in compatible workpiece materials.

Installation Notes

This tap is intended for use by machinists or skilled maintenance technicians using a calibrated tap wrench. The workpiece should be secured firmly before tapping begins, and appropriate cutting fluid should be applied to reduce heat and extend tap life. Back the tap out periodically to break and clear chips, especially in deeper holes. Never apply excessive side force or use power drivers not rated for hand-tap geometry, as tap breakage in left-hand applications can be difficult to recover from.