Value Collection JY4872180 Hand Tap 1-3/8-18 Unef

Product Description

The VALUE COLLECTION JY4872180 is a straight-flute hand tap designed for cutting 1-3/8-18 UNEF internal threads in through-holes and blind holes requiring thread cut to the bottom. Manufactured from high speed steel with a bright, uncoated finish, this tap delivers consistent performance in general threading applications across a range of ferrous and non-ferrous materials. The bottoming chamfer — typically 1 to 2 threads of lead — allows the tap to cut threads as close to the base of a blind hole as possible. At 4 inches overall length, it fits standard tap wrenches used in manual hand-tapping operations. The 6-flute geometry provides ample chip clearance and a stable cutting action in moderate-to-light duty applications.

This tap is suited for maintenance, repair, and production threading tasks where a UNEF 1-3/8-18 thread is required. The bottoming configuration makes it the final tap used in a three-tap sequence — after taper and plug taps have started and progressed the thread — or as the sole tap in through-hole applications where full thread depth at the bottom of a blind bore is critical. It is commonly used by machinists, millwrights, and mechanical contractors working on threaded fastener repairs, tooling fixtures, and precision assemblies.

Key Features

• Bottoming chamfer for threading to the bottom of blind holes
• 1-3/8-18 UNEF thread form meets Unified National Extra Fine standards
• 6-flute straight-flute design provides stable cutting and chip control
• High speed steel construction handles a broad range of workpiece materials
• Bright, uncoated finish — no coating buildup to affect thread tolerance
• Class of fit 3B with H4 thread limit for close-tolerance threaded connections

Compatibility

Designed for use in standard manual tap wrenches and T-handle wrenches that accept taps at this shank size. Cuts 1-3/8-18 UNEF right-hand internal threads in compatible workpiece materials.

Installation Notes

Hand tapping should be performed with the workpiece securely fixtured and the tap aligned perpendicular to the bore to prevent tap breakage and cross-threading. Apply cutting oil or tapping fluid appropriate to the workpiece material before and during the tapping operation. In a blind hole, clear chips frequently by reversing the tap to break and evacuate chips, especially with a bottoming tap at final depth. Inspect the tap for wear or chipping before each use; a damaged tap can ruin a workpiece and create extraction hazards.