Osg 1705108 Spiral Flute Tap 5/8-18 Unf Modified Bottoming

Product Description

The OSG 1705108 is a spiral flute tap designed for cutting 5/8-18 UNF internal threads in demanding materials. Built from powdered metal and finished with a TICN coating, this tap handles alloy steel, stainless steel, hardened steel, titanium, and high-nickel alloys. It features a modified bottoming chamfer for threading close to the bottom of blind holes, with a right-hand spiral flute geometry at a 15-degree helix angle that evacuates chips upward during cutting. Class of fit is 2B with an H5 thread limit, providing a standard commercial fit suitable for most fastener applications. Overall length is 3-13/16 inches. Licensed machinists and toolroom technicians are the primary users of this tap.

The OSG 1705108 is suited for production and maintenance machining environments where blind-hole threading in tough alloys is required. The modified bottoming chamfer allows threading within a few pitches of the hole bottom, making it useful in close-tolerance assemblies where full thread depth is critical. The TICN coating reduces friction and extends tool life in abrasive and work-hardening materials such as stainless steel and titanium. It is used in CNC tapping operations as well as manual tapping setups where consistent 2B-class threads are required in 5/8-18 UNF applications.

Key Features

• 5/8-18 UNF thread form, 2B class of fit, H5 thread limit for standard commercial tolerances
• Modified bottoming chamfer allows threading close to the bottom of blind holes
• Powdered metal construction provides consistent hardness and wear resistance across tough workpiece materials
• TICN coating reduces friction and heat buildup, extending tool life in stainless steel, titanium, and high-nickel alloys
• 15-degree right-hand spiral flute geometry promotes upward chip evacuation in blind-hole applications
• 4 flutes for balanced cutting load distribution during tapping

Compatibility

Designed for threading alloy steel, stainless steel, hardened steel, titanium, and high-nickel alloy workpieces. Part of the OSG EXOTAP Series 313 product line. No specific machine or chuck compatibility data was provided in the product input.

Installation Notes

This tap should be installed in a tap holder or collet chuck rated for the shank diameter of 0.8 inches. Always ensure the workpiece is secured and the spindle speed and feed rate are set per the tap manufacturer recommendations for the specific workpiece material before starting the cut. Cutting fluid or tapping compound appropriate for the workpiece material should be applied to reduce heat and improve surface finish. Inspect the tap for wear or chipping before each use, as damaged cutting edges in hardened or abrasive materials can result in tap breakage or out-of-tolerance threads.