Osg 1719008 Spiral Flute Tap 4-40 Unc 3 Flute 2B Ticn

Product Description

The OSG 1719008 is a spiral flute tap designed for threading 4-40 UNC holes in difficult-to-machine materials. It features three right-hand spiral flutes with a 10-degree helix angle and a modified bottoming chamfer, making it suitable for threading close to the bottom of blind holes. Built from powdered metal and finished with a TICN coating, this tap delivers extended tool life in demanding applications. With an overall length of 1.875 inches and a thread length of 0.559 inches, it is sized for use in standard machine tap holders and CNC tapping equipment. Licensed machinists and toolroom technicians are the typical end users.

This tap is rated for use in stainless steel, hardened steel, titanium, and high-nickel alloys, making it a strong choice for aerospace, medical device, and precision manufacturing environments. The 2B class of fit produces threads within standard commercial tolerance for most threaded fastener applications. The H2 thread limit provides a close controlled fit appropriate for these material types. It is suited to both CNC machining centers and rigid tapping setups where consistent thread quality in tough alloys is required.

Key Features

• 4-40 UNC thread form with 40 threads per inch and right-hand thread direction
• TICN coating reduces friction and improves wear resistance in high-nickel and titanium alloys
• Powdered metal construction provides greater hardness and toughness compared to standard HSS
• Modified bottoming chamfer allows threading close to the bottom of blind holes
• 10-degree right-hand helix angle promotes chip evacuation out of the flutes during tapping
• H2 thread limit and 2B class of fit for consistent, inspectable thread tolerance

Compatibility

Designed for use in stainless steel, hardened steel, titanium, and high-nickel alloy workpieces requiring 4-40 UNC internal threads. Part of the OSG Series 313NI product line.

Installation Notes

This tap should be installed by a qualified machinist familiar with rigid or floating tap holders and proper cutting fluid selection for the workpiece material. Always confirm spindle speed and feed rate are appropriate for the material and tap size before operation. Use appropriate cutting or tapping fluid for stainless steel and high-nickel alloys to prevent galling and premature tool wear. Inspect the tap for chipping or wear before each use, as small-diameter taps in hard materials are susceptible to breakage if run in worn condition.