The bolt with an oil-bearing hole and spiral oil-guiding slot

bolts A bolt is an externally helical threaded fastener that can be tightened or loosened by torque on the mating nut The bolt has an external male thread

20240418 - SILHOUETTE XL 916 Bolt Slot

bolt slot Assuming this is a planar slot in one direction, I would create a user defined coordinate system with one of the axes aligned in the direction

bolt slot grid Explanation: T-headed bolt This form of the bolt is just like a T and is used for securing vice, jigs, etc to the tables of machine tools in which T-slots