天津生产DIN939双头螺柱，销售DIN939双头螺柱DIN912内六角螺丝，天津生产DIN939双头螺柱，销售DIN939双头螺柱碳钢DIN580吊环螺丝天津生产DIN939双头螺柱，销售DIN939双头螺柱DIN913平端顶丝,天津生产DIN939双头螺柱，销售DIN939双头螺柱DIN914尖端顶丝,天津生产DIN939双头螺柱，销售DIN939双头螺柱DIN916凹端顶丝,DIN933外六角螺丝,DIN7991沉头内六角螺丝，ISO7380盘头内六角螺丝,英美制内六角外六角，DIN7984薄头内六角螺丝。不锈钢喉塞。