Osg 3110808 Machine Tap 5/16-18 Unc Ticn Solid Carbide

Product Description

The OSG 3110808 is a solid carbide straight flute machine tap designed for threading 5/16-18 UNC holes in demanding materials. The 5-flute geometry and TiCN (Titanium Carbonitride) coating work together to handle high-hardness workpieces where standard high-speed steel taps fail. The modified bottoming chamfer allows threading close to the bottom of blind holes, making this tap well-suited for tight-tolerance applications. At 90mm overall length with a 1.125-inch thread length and a 0.318-inch shank diameter, this tap is sized for use in standard machine tap holders. It is sold individually and intended for use by machinists and toolroom professionals operating CNC or manual tapping equipment.

This tap is specifically rated for use in cobalt chrome alloy steel and hardened steel — two of the most abrasion-intensive materials in precision machining. The 5/16-18 UNC thread size and 2B class of fit make it appropriate for standard fastener applications requiring a free-running fit with controlled tolerance. Typical installation scenarios include aerospace, medical device, and die-mold shops where hardened workpieces demand carbide tooling. The right-hand thread direction and straight flute configuration suit through-hole and moderate-depth blind-hole applications where chip evacuation is managed by the operator or coolant flow. Coolant-through capability is not available on this model.

Key Features

• Solid carbide construction for rigidity and wear resistance in hardened and cobalt chrome alloy steel
• TiCN coating reduces friction and extends tool life in abrasive materials
• 5-flute design increases contact points for improved thread finish and tap stability
• Modified bottoming chamfer enables threading near the bottom of blind holes
• 2B class of fit meets standard UNC tolerance requirements for free-running fastener assemblies
• Right-hand, straight flute geometry compatible with standard machine tap holders and CNC tapping cycles

Compatibility

Designed for use in machine tapping applications requiring a 5/16-18 UNC thread in cobalt chrome alloy steel or hardened steel. Part of the OSG Series 311 solid carbide tap lineup.

Installation Notes

This tap should be installed by qualified machinists familiar with carbide tooling requirements. Secure the tap in a rigid holder rated for solid carbide tools — floating or tension-compression holders may introduce runout that can fracture carbide. Power down and lock out all equipment before changing tooling. Follow the machine manufacturer and applicable shop safety guidelines for speeds, feeds, and lubrication when tapping hardened materials, as carbide tooling is brittle and sensitive to lateral loading.