Machining > Threading > Tap Sets | Bordo MF Chrome Alloy Spark Plug Hand Tap Set | Bordo MF Chrome Alloy Spark Plug Hand Tap Set | Chrome Alloy Spark Plug (Metric Fine) Hand Tap Set. | Used as thread chasers to clean an existing thread. | They can also be used to create a new female thread in non-ferrous metals and plastics. | Chrome alloy taps are not suitable for creating precision, safety or critical threads. | Metric Fine angle of thread is 60 degrees. | The crest is flat and the thread has clearance at the root allowing external thread and internal thread to engage well. | Larger root radius and lower thread height enable easy screw thread processing and increase thread screw strength. | The major diameter of external thread and pitch are specified by a simple numerical value (most commonly measured in millimetres). | 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. | Taper Taps have a lead of eight threads and are used as a starting tap in difficult or high precision holes. | Intermediate Taps have a lead of four threads and are used in most general purpose applications to cut a thread true to a pre-drilled pilot hole. | Bottoming Taps are typically preceded by the use of a Taper or Intermediate Tap.