Greenfield 328448 M6x1.0 Bottoming Hand Tap 4 Flute D5 Hss

Product Description

The GREENFIELD 328448 is a straight-flute bottoming hand tap designed for cutting M6x1.0 metric threads in blind hole applications. Built from high-speed steel with a bright finish, it delivers consistent thread quality in cast iron, steel, stainless steel, and non-ferrous materials. The D5 thread limit establishes the allowable tolerance for the finished thread, targeting a 6H class of fit standard in metric threading work. The HTGP series configuration with a 0.255-inch straight shank with square drive is compatible with standard tap wrenches. Overall length is 2.5 inches. This tap is suited for machinists, maintenance technicians, and trade professionals performing metric threading operations by hand.

The 328448 is intended for general-purpose metric threading in blind holes where a bottoming chamfer is required to cut threads close to the bottom of a bore. The bottoming chamfer style allows thread cutting to within 1-2 threads of the blind hole base, making it the correct choice when a plug or taper tap cannot reach the required thread depth. Typical applications include repair threading, fixture fabrication, and component assembly across industrial and commercial maintenance settings. This tap is packaged 6 per case, making it practical for shop stocking.

Key Features

• Bottoming chamfer style for threading close to the bottom of blind holes
• M6x1.0 thread size with D5 thread limit and 6H class of fit
• 4-flute straight flute geometry for chip management in through and blind holes
• High-speed steel construction with bright finish for general-purpose cutting applications
• Right-hand cutting direction for standard metric thread production
• Compatible with cast iron, steel, stainless steel, and non-ferrous materials

Compatibility

Designed for use in standard tap wrenches or T-handle drivers accepting a straight shank with square drive. Suitable for M6x1.0 metric threading operations conforming to ground coarse thread standards with a 6H class of fit tolerance.

Installation Notes

Hand tapping should be performed by a qualified machinist or maintenance technician using a properly sized tap wrench. Secure the workpiece before beginning and apply appropriate cutting fluid for the material being tapped to reduce heat and improve thread finish. Back the tap off periodically to break chips and prevent tap breakage, particularly in deep blind holes. Never force a tap against resistance — back out and clear chips before continuing.

Technical Specifications

• Thread Size: M6x1.0
• Thread Form: Metric
• Thread Standard: Ground Coarse
• Thread Limit: D5
• Class of Fit: 6H
• Number of Flutes: 4
• Chamfer Type: Bottoming
• Cutting Direction: Right Hand
• Overall Length: 2.5 inches (63.5 mm)
• Thread Length: 16 mm
• Shank Diameter: 6.48 mm
• Material: High-Speed Steel (HSS)
• Finish: Bright
• Material Application: Cast Iron, Steel, Stainless Steel, Non-Ferrous Materials
• Series: HTGP
• Measurement System: Metric
• Package Quantity: 6 per case

Standard Information

• Brand: GREENFIELD
• Manufacturer Part Number: 328448