美制平行管螺纹用丝攻 NPSF

平行螺纹 NPSF

平行外螺纹 Tredo ; USIT ring

公制内螺纹平面 METRIC FEMALE FLAT SEAT

英制标准平型管螺纹 BSP parallel

平头柱纹铆螺母 FLAT HEAD KNURLED RIVET NUTS ; FLAT HEAD RIBBED INSERT NUT

平板螺纹辊模 flat thread die

螺纹平垫密封 seal by flat gasket

平行的螺纹两个末端 PARALLEL THREAD BOTH ENDS

内螺纹平行销 Parallel pins with internal thread