Osg 1725301 Spiral Point Tap 7/8-14 Unf 3 Flute Plug

Product Description

The OSG 1725301 is a spiral point plug tap designed for cutting right-hand internal threads to a 7/8-14 UNF specification. It is manufactured from vanadium high-speed steel (HSS-E) and finished with a steam oxide coating that reduces friction and provides light corrosion resistance during storage and use. The plug chamfer distributes cutting forces across the leading threads for smooth entry into through-holes. With a 3B class of fit and H4 thread limit, this tap produces threads within close commercial tolerances. Overall length is 4.689 inches, and the threaded length is 1.37 inches. It is used by machinists, tool-and-die makers, and maintenance technicians working in metal fabrication and industrial repair.

This tap is suited for through-hole tapping applications in a range of ferrous materials. Its HSS-E construction and oxide coating make it appropriate for use in low-carbon steel, medium-carbon steel, hardened steel, and stainless steel workpieces. The spiral point geometry pushes chips forward ahead of the tap, keeping flutes clear in through-hole conditions. It is a single-piece tap from OSG Series 300, intended for use in both manual and machine tapping setups where a 7/8-14 UNF thread form is required.

Key Features

• 7/8-14 UNF thread form with 3B class of fit and H4 thread limit for close commercial tolerances
• Spiral point geometry pushes chips forward, suited for through-hole tapping
• Vanadium high-speed steel (HSS-E) construction for durability in ferrous materials
• Steam oxide coating reduces friction and provides light corrosion resistance
• Plug chamfer distributes cutting load across leading threads for smooth entry
• Right-hand thread direction, non-coolant-through design

Compatibility

Designed for through-hole tapping of 7/8-14 UNF threads in low-carbon steel, medium-carbon steel, hardened steel, and stainless steel. Suitable for manual tap handles and machine tapping operations using standard 7/8-14 UNF toolholding.

Installation Notes

Power down or de-energize any machine before installing or changing taps. Secure the tap in an appropriately sized tap wrench or machine holder rated for the shank diameter before beginning the tapping operation. Apply a cutting fluid appropriate for the workpiece material, particularly when working with stainless or hardened steel. Inspect threads with a 3B go/no-go gauge after tapping to verify fit before assembly.