Osg 2842501 Spiral Point Tap 7/16-20 Unf 3 Flute Plug

Product Description

The OSG 2842501 is a spiral point plug tap designed for threading through-holes in a wide range of ferrous and non-ferrous materials. Built from 3% vanadium high-speed steel (HSS-E) with a steam oxide coating, the tap offers improved lubricity and corrosion resistance during cutting operations. It cuts a 7/16-20 UNF right-hand thread and carries a H7 thread limit designation, indicating a slight oversize tolerance suitable for applications requiring thread fit in the upper tolerance range. With 3 flutes and a plug chamfer, it is engineered for production tapping in materials where chip evacuation through the front of the hole is acceptable. Licensed machinists, toolmakers, and maintenance technicians commonly use this tap in CNC and manual tapping operations.

This tap is suited for threading through-holes in aluminum, low-carbon steel, medium-carbon steel, high-carbon steel, alloy steel, die steel, stainless steel, cast iron, and hardened steel. The plug chamfer provides a gradual lead-in over several threads, making it appropriate for production environments where through-hole tapping is the standard operation. It is part of OSG Series 280 and is packaged as a single unit. It is not configured for coolant-through delivery, making it a straightforward choice for conventional tapping setups.

Key Features

• 7/16-20 UNF right-hand thread form with H7 oversize thread limit
• 3% vanadium high-speed steel construction for extended tool life in tough materials
• Steam oxide coating reduces friction and improves chip flow during cutting
• Plug chamfer provides gradual thread engagement, optimized for through-hole applications
• 3-flute spiral point design pushes chips forward ahead of the tap
• Compatible with a broad material range including stainless steel, alloy steel, and cast iron

Compatibility

Designed for through-hole tapping applications requiring a 7/16-20 UNF thread in aluminum, hardened steel, stainless steel, high-carbon steel, low-carbon steel, medium-carbon steel, alloy steel, die steel, and cast iron. This tap is part of OSG Series 280.

Installation Notes

Tapping operations should be performed by qualified machinists following standard shop safety procedures. Ensure the workpiece is securely fixtured and the spindle is properly aligned before beginning the tapping cycle. Apply an appropriate cutting fluid for the workpiece material to extend tap life and improve thread finish. This tap is not designed for blind-hole applications where chip evacuation at the bottom of the hole is required - use a bottoming or spiral flute tap for those setups.