http://goo.gl/hqyDjl
Tethered plug drawing, also known as semi-floating mandrel drawing, is a mix between floating plug drawing and fixed plug drawing. The mandrel is allowed to float, but it still anchored via a tether. This process gives similar results to the floating plug process, except that it is designed for straight tubes. It gives a better inner surface finish than rod drawing.

Это как волочение на плавающей оправке, но эта оправка подвижно закреплена (канатом каким-нибудь?). Интересно, как это по-русски принято называть. В РуВики нет вроде бы варианта.