Structural steel part for reinforcement or anchorage comprises bar with outside thread ribs at specified spacing and pitch and at angle to bar axis using externally threaded coupling nuts to join steel parts.

摘要

The ratio of rib (5) height (b) to rib interval (a) is 0.15 and the rib outside surfaces are set at more than 45 to 70[deg] to the bar axis (alpha ). The preferably multiple outside thread (3) pitch is between 5 and 10[deg]. The several steel parts (1) are joined by externally ribbed coupling nuts forming an outside trapezoidal thread of prefered pitch of 5-10[deg].