This conventional thread machining technique is normally found in both flexible manufacturing system lines and transfer lines for mass production and also is very popular in service shops.
This flexible and user-friendly threading system enables use of a wide range of carbide inserts in two main sizes:
15.875 mm (5/8”) and 25 mm (63/64”).
The insert thickness for the 15.875 mm (5/8”) size is 4.76 mm (3/16”) and 5 mm (13/64”) for 25 mm (63/64”). The 25 mm (63/64”) size is commonly called “chaser” and is suitable for a multi-tooth configuration. The first tooth performs the rough operation, the middle ones the semi-finish operation and the last tooth is for the finishing operation.
Thread profiles are commonly divided in two main groups: API & Premium. The API profiles are buttress (trapezoidal shape) and round, while the Premium profile variety is much wider.
Thread profile tolerances on API are relatively open, up to 0.005 mm (0.0002”).
On Premium profiles, not only the profile shape is different but also the tolerances are much tighter, up to 0.0025 mm (0.0001”). All the threading inserts have an internal coolant hole.
