metric plum grub screw公制无头梅花螺丝
hollow grub screw平头空心螺钉
conical pointed grub screw锥形沉头螺钉;锥端无头螺钉
hexagon socket grub screw六角凹头无头螺钉
grub screw thread无头螺钉螺纹
lock grub screw锁紧螺丝
N（名词） a small headless screw having a slot cut for a screwdriver or a socket for a hexagon key and used to secure a sliding component in a determined position 无头螺丝