Osg 1741705 Spiral Point Plug Tap 5/8-18 Unf 3 Flutes Tin

Product Description

The OSG 1741705 is a spiral point plug tap designed for threading through-holes to a 5/8-18 UNF specification with a 3B class of fit. Manufactured from Vanadium High Speed Steel (HSS-E) and finished with a Titanium Nitride (TiN) coating, this tap handles elevated cutting temperatures while extending tool life across demanding materials. The spiral point geometry pushes chips ahead of the cut, keeping flutes clear in through-hole applications. With 3 flutes and an H3 thread limit, it produces accurate, consistent threads at production volumes. Overall length is 3.811 inches, with a thread length of 1.91 inches and a shank diameter of 0.48 inches. Licensed machinists, tool-and-die makers, and maintenance mechanics are the typical users.

This tap is suited for threading through-holes in a broad range of materials encountered in general machining, tool-and-die work, and industrial maintenance. Rated material applications include aluminum, hardened steel, stainless steel, high-carbon steel, low-carbon steel, medium-carbon steel, alloy steel, die steel, and cast iron. The plug chamfer distributes the cutting load across the first few threads and is the correct choice when starting the tap from a drilled-through hole with reasonable lead-in clearance. Right-hand thread direction is standard for conventional fastener applications.

Key Features

• 5/8-18 UNF thread form, 3B class of fit, H3 thread limit for close-tolerance work
• Spiral point geometry pushes chips forward — optimized for through-hole tapping
• Vanadium High Speed Steel (HSS-E) construction for heat and wear resistance
• TiN coating reduces friction and extends tool life in abrasive and high-volume applications
• Plug chamfer for stable thread engagement from an open through-hole
• Right-hand cut, no coolant-through requirement, no interrupted thread design needed

Compatibility

Designed as an OEM-style production tap for through-hole applications requiring a 5/8-18 UNF right-hand thread in ferrous and non-ferrous workpiece materials including aluminum, stainless steel, alloy steel, die steel, and cast iron.

Installation Notes

This tap is installed by machinists and tool-and-die professionals using a tap handle, tapping head, or CNC rigid-tap cycle. Ensure the workpiece is securely fixtured and the pilot hole diameter matches the recommended drill size for 5/8-18 UNF before tapping. Apply cutting fluid appropriate to the workpiece material to reduce heat and extend tool life. Inspect the tap for chipping or wear between uses — a dull or damaged tap produces undersized, out-of-tolerance threads.