Osg 1970102 Straight Flute Tap M3x0.50 Metric Coarse Hss

Product Description

The OSG 1970102 is a straight flute plug tap designed for cutting internal metric coarse threads in a wide range of ferrous and non-ferrous materials. Built from high-speed steel, it delivers consistent thread quality in through-hole and open-ended blind-hole applications. The plug chamfer style features a moderate lead that centers the tap before full thread engagement, making it well suited for general-purpose tapping work. With 3 flutes and a D3 thread limit, it produces a 6H class of fit, which meets standard tolerance requirements for most metric fastener assemblies. Overall length is 1-15/16 inches with a thread length of 5/8 inches. Machinists, tool-and-die makers, and maintenance technicians are the primary users.

This tap is intended for threading M3x0.5 metric coarse holes in materials including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The straight flute geometry works best in shorter chipping materials where chip evacuation through the flutes is not a limiting factor. It is suited for use in manual tap handles, CNC machining centers, and drill press tapping setups where the right-hand thread direction is required. Coolant-through capability is not available on this tap, so external cutting fluid application is standard practice.

Key Features

• M3x0.50 metric coarse thread form with right-hand thread direction
• Plug chamfer provides moderate lead-in for general through-hole and open blind-hole tapping
• High-speed steel construction for durability across a broad material range
• 3 straight flutes with D3 thread limit produce a 6H class of fit
• Thread length of 5/8 inches and overall length of 1-15/16 inches
• Compatible with aluminum, cast iron, and low- to high-carbon steel workpieces

Compatibility

Designed for cutting M3x0.50 metric coarse internal threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. Suitable for use with standard tap handles and CNC tapping attachments that accept straight-shank taps of this size class.

Installation Notes

Tapping operations should be performed by a qualified machinist or maintenance technician following standard shop safety practices. Ensure the workpiece is securely fixtured and the pilot hole is drilled to the correct M3x0.50 tap drill diameter before beginning thread cutting. Apply a suitable cutting fluid to the tap and workpiece throughout the operation to reduce heat and extend tool life. Reverse the tap periodically to break chips and prevent tap breakage, particularly in deeper holes.