Accupro 17947-01T M4x0.70 Thread Forming Tap Bottoming Tin

Product Description

The ACCUPRO 17947-01T is a thread forming tap designed for M4x0.70 metric coarse internal threading in blind hole applications. Unlike cutting taps, this forming tap displaces material rather than removing it, producing stronger, work-hardened threads with no chips to clear. Constructed from powdered metal high-speed steel and coated with titanium nitride (TiN), it delivers extended tool life in ferrous and non-ferrous materials. The bottoming chamfer configuration with 2.5 chamfered threads allows threading close to the bottom of a blind hole. Class of fit is 6H with a D6 thread limit, meeting standard metric tolerance requirements. Licensed machinists and toolroom technicians are the primary users.

This tap is suited for production and maintenance threading operations where M4x0.70 metric coarse internal threads are required in blind holes. The right-hand thread direction and bottoming chamfer make it appropriate for close-tolerance work in machine components, fixtures, and assemblies. The TiN coating reduces friction and heat buildup during the forming process, extending service intervals in repetitive tapping cycles.

Key Features

• Thread forming design displaces material for chip-free, stronger threads in blind holes
• Powdered metal high-speed steel construction provides consistent hardness and wear resistance
• Titanium nitride (TiN) coating reduces friction and extends tool life
• Bottoming chamfer with 2.5 chamfered threads allows threading near the base of blind holes
• Class 6H fit and D6 thread limit for standard metric tolerance compliance
• Right-hand thread direction with a single oil groove for lubrication distribution

Compatibility

Designed for forming M4x0.70 metric coarse right-hand internal threads in blind hole applications across standard CNC machining centers, drill presses, and tapping machines equipped with appropriate toolholding for a 0.168-inch shank diameter.

Installation Notes

Thread forming taps require proper hole preparation — the pilot hole diameter must be sized for forming, not cutting, so consult a metric forming tap drill chart for the correct pre-drill size for M4x0.70. Use a suitable tapping fluid or cutting oil compatible with the workpiece material to protect the TiN coating and the workpiece surface. Secure the workpiece fully before tapping and ensure the tap is driven axially true to prevent thread distortion or tool breakage. Do not use this tap as a cutting tap — it is designed exclusively for ductile materials that can be cold-formed.