The characteristic of the disk type screwthread is that its radial size is far greater than axial size and it is processed out square thread on its head face.

• 盘型螺纹特点是其径向尺寸远远大于轴向尺寸,并在端面上加工出方牙螺纹,由于螺纹的旋向由外向里,其螺旋线由大变小。