Osg 1970502 Straight Flute Tap M4x0.70 Metric Coarse Hss

Product Description

The OSG 1970502 is a straight flute bottoming tap designed for cutting metric coarse internal threads to M4x0.70 specification. Built from high-speed steel, this 4-flute tap produces a 6H class of fit thread with a D4 thread limit, making it suitable for tight-tolerance applications. The bottoming chamfer style allows threading close to the bottom of blind holes. With an overall length of 2.125 inches and a thread length of 0.75 inches, the tap fits standard toolholding setups used in manual and CNC tapping operations. Licensed machinists and tool-and-die tradespeople are the primary users.

This tap is suited for production and maintenance tapping in ferrous and non-ferrous metals. Confirmed material applications include aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel. It is used in applications where a bottoming tap is needed to thread the full depth of a blind hole after a taper or plug tap has started the thread. Right-hand thread direction follows standard M4 bolt patterns across these materials.

Key Features

• M4x0.70 metric coarse thread form with 6H class of fit
• Bottoming chamfer for threading to the base of blind holes
• 4-flute straight flute geometry for chip control in through and blind hole applications
• High-speed steel construction for use across a broad range of metals
• D4 thread limit for controlled tolerance output
• Right-hand thread direction, overall length 2.125 inches, thread length 0.75 inches

Compatibility

Designed as a straight flute bottoming tap for M4x0.70 metric coarse threaded holes in aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel workpieces.

Installation Notes

Install in a standard tap wrench, tapping head, or CNC toolholder rated for the shank diameter before use. Ensure the workpiece is securely fixtured and the pilot hole is drilled to the correct M4x0.70 minor diameter before tapping. Apply appropriate cutting fluid for the workpiece material to reduce heat and extend tap life. Inspect the tap for chipping or wear before each use, as a damaged tap can destroy the thread or break off in the hole.