Screw, M8x25 Square Head Dog Point Machine
These are the square head dog point machine screws used to clamp tools in the standard tool post on the 8x12 and 8x14 lathe.
In your instruction manual, this part appears on the parts list as:
|412||Harbor Freight 44859 Central Machinery Lathe - 8x12|
Various C8-US SIEG Lathe