Wiseman HSS NPT Hexagon Die Nuts – National Pipe Taper Right Hand Thread

Wiseman HSS NPT Hexagon Die Nuts are manufactured from High Speed Steel (HSS) and designed for repairing, cleaning and restoring damaged or worn external NPT (National Pipe Taper) threads.

These precision-engineered hexagon die nuts feature a fixed, non-adjustable design and can be operated using a suitable spanner or socket, making them particularly useful for maintenance, repair and general engineering applications.

NPT threads feature a 60° thread profile with a taper of 1 in 16 on diameter, allowing tapered male and female threads to engage progressively. They are widely used in pipe fittings, fluid transfer systems, compressed air equipment and industrial machinery.

Manufactured with a right-hand thread profile, these die nuts are suitable for restoring existing NPT threads on pipes, fittings and other externally threaded components.

Key Features

• High Speed Steel (HSS) – Durable construction for reliable thread restoration and maintenance.

• NPT Thread Form – Designed for American National Pipe Taper external threads.

• Right Hand Thread – Standard clockwise tightening thread direction.

• Hexagon Design – Can be operated using a suitable spanner or socket.

• Thread Repair & Restoration – Ideal for cleaning, chasing and restoring damaged or worn external pipe threads.

• Fixed Die Nut – Non-adjustable design for consistent thread engagement.

• 60° Thread Profile – American pipe thread form with a 1:16 taper on diameter.

• Tapered Pipe Thread – Suitable for maintenance of components using NPT threaded connections.

• Professional Quality – Manufactured by Wiseman Threading Tools for engineering and maintenance applications.

Applications

Suitable for:

• Repairing damaged NPT threads on pipes and fittings.

• Cleaning existing external tapered pipe threads.

• Restoring worn or contaminated threads.

• General engineering and workshop maintenance.

• Compressed air and pneumatic equipment.

• Hydraulic and fluid transfer equipment using NPT connections.

• Industrial machinery and pipework maintenance.

• Maintenance of threaded adapters, connectors and pipe fittings.

Recommended Use

Select the correct NPT thread size and pitch to match the existing external thread.

Position the die nut squarely onto the thread and rotate using a suitable spanner or socket. Apply an appropriate cutting lubricant where required and avoid excessive force.

Hexagon die nuts are primarily intended for thread cleaning, chasing and restoration rather than cutting new threads from plain pipe or bar stock.

After thread restoration, inspect the thread for damage and verify the connection using the appropriate NPT thread gauge and assembly requirements.

Important

• Suitable for NPT (National Pipe Taper) right-hand external threads only.

• Not compatible with BSPT, BSPP, NPS or metric pipe threads.

• NPT threads feature a 60° profile and a 1:16 taper on diameter.

• Non-adjustable hexagon die nut.

• NPT nominal pipe sizes do not correspond directly to the outside diameter of the thread.

• Ensure the correct nominal pipe size and threads per inch (TPI) are selected before use.