diameter 5 - 15 mm

Four way measurement

Detachable Bar & Chain Oil compartment for easy cleaning

With convex (domed) striking faces

BSW Bottoming HSS Tap by Bordo Dust Hose diameter 5 - 15 mmAbout this product: HSS BSW Bottoming Hand and Machine Tap. British Standard Whitworth has a thread angle of 55 degrees as opposed to 60 degrees in Metric and Unified threads. This thread form was developed by Sir Joseph Whitworth in 1841. The thread form has rounded roots and crests and is specified in BS84: 1956. Bottoming Taps have a lead of two threads and are used to ensure minimum thread run out when tapping to the bottom of a blind hole.