Multiple start thread is similar to standard thread, but lead of helix has, this case, bigger values. The "i" number of starts are here interfingering and, actually, the thread pitch is, an "i" times multiple of the circumferential pitch.
The case of multiple start threads some of dimensional characteristics are different enough and, by consequence, there are some functional characteristics also modified. Among these, the screw-on torque level increase brings here several advantages. Despite some certain benefits of multiple start thread use, in shouldered pipe connections domain these are not sufficiently extensive; the main drawback here appears the demanding manufacturing.
Constructive-technological restrictions - far less investigated - must be known, understood and optimally solved and overcome. Thus becomes possible wider use of such special thread.
One of the essential advantige of multiple start thread use for drilling stem connections refers to the torque moments. For drilling stem joints, the working torque moment, (Mw,), must obvious be lesser than tightening torque (Ms) here applied - for necessarly avoid the under load re-clamping. This way, the multiple start thread becomes a relevant solution to increase the working torque level, when it is required.