double convex ring 双凸环

double cooling and heating back counter reshaping machine 双冷热式鞋后跟整形机

double copper-wire crosstalk suppression filter 双铜线串音抑制滤波器

double core optical fiber 双芯光纤

double core plastic wire 双芯塑料线

double cote 双棱哔叽

double cotton-covered copper wire 双纱铜包线

double cotton-covered enamelled wire 双纱漆包线

double coverlet 夹被

double crane 双钩起重机

double crank 双曲柄

double crankless press 两点式无曲柄压力机

double crepe de chine 双绉

double crystal spectrometer 双晶分光计

double crystal X-ray goniometer 双晶体X射线测角仪

double crystal X-ray spectrometer 双晶体X射线光谱计

double cup insulator 双杯形绝缘子

double cup wheel 双面凹砂轮

double current furnace 交直流电炉

double cutter shearing machine 双刀辊剪毛机

double cutting drill 双刃钻

double cylinder automatic rib machine 双针筒自动罗纹机

double cylinder board machine 双圆网纸板机