Wiseman HSS BSW Split Dies – British Standard Whitworth Right Hand Thread

Wiseman HSS BSW Split Dies are manufactured from High Speed Steel (HSS) and designed for cutting new external BSW (British Standard Whitworth) threads, as well as repairing, cleaning and restoring damaged or worn existing threads.

These precision-engineered round split dies feature an adjustable split design, allowing minor adjustments to the thread fit when used with a suitable die stock. This makes them particularly useful for general engineering, thread cutting, maintenance and workshop applications.

BSW threads feature a 55° Whitworth thread profile with rounded crests and roots. British Standard Whitworth threads are commonly found on older British machinery, vintage vehicles, agricultural equipment and traditional engineering components.

Manufactured with a right-hand thread profile, these split dies are suitable for producing and restoring BSW threads on bolts, studs, rods and other externally threaded components.

Key Features

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

• BSW Thread Form – Designed for British Standard Whitworth external threads.

• Right Hand Thread – Standard clockwise tightening thread direction.

• Adjustable Split Design – Allows minor adjustment of the thread fit when used with a suitable die stock.

• Round Die Construction – Designed for use with compatible die stocks and die holders.

• Thread Cutting & Restoration – Suitable for cutting new external threads and repairing existing threads.

• 55° Thread Profile – Whitworth thread form featuring rounded crests and roots.

• Versatile Applications – Suitable for general engineering, restoration and maintenance work.

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

Applications

Suitable for:

• Cutting new BSW external threads on rods, bolts and studs.

• Repairing damaged or worn BSW threads.

• Cleaning and restoring existing external threads.

• General engineering and workshop machining.

• Vintage and classic vehicle restoration.

• Maintenance of older British machinery and equipment.

• Agricultural machinery repairs.

• Manufacturing replacement bolts and studs.

• Applications requiring British Standard Whitworth threads.

Recommended Use

Select the correct BSW split die size and pitch to match the required external thread.

Secure the die in a suitable die stock or holder, ensuring the adjustment screws are correctly positioned. Prepare the workpiece to the appropriate diameter and apply a suitable chamfer to help the die start squarely.

Apply an appropriate cutting lubricant and rotate the die clockwise to cut the thread. Periodically reverse the die slightly to help break and clear chips where appropriate for the material and cutting conditions.

The adjustable split design allows minor adjustments to the thread fit. For accurate results, check the finished thread using a suitable thread gauge or mating component.

Important

• Suitable for BSW (British Standard Whitworth) right-hand external threads only.

• Not compatible with BSF, UNC, UNF, metric or other thread forms unless the exact thread specifications match.

• Adjustable round split die for cutting and restoring external threads.

• Requires a compatible die stock or die holder.

• Ensure the correct thread diameter and threads per inch (TPI) are selected before use.