At present,the sucker rod used in screw pump is the threadless rod used in beam unit.The threadless rod is suited for up and down reciprocating motion,tensile strength is main antiforce index of rod.

• 在用螺杆泵抽油杆大多都是沿用抽油机上使用的平扣抽油杆,适合于上下往复运动,抗拉强度是抽油杆的主要抗力指标。