The two on the left are Chinese Pointed Angle Grind Spike Bayonet with their sharp tip ground from both sides angled toward the front and bottom. The bottom right is a Chisel Tip Spike AK47 Bayonet that is ground from the top angled down in a “Chisel” shape The other side of the two Chinese Pointed Spike Bayonets
The bottom is a “Chisel Tip” AK47 Spike Bayonet
The top two are examples of the Chinese Angle Grind Spike Bayonets.
The bottom is a Chisel Tip Spike AK47 Bayonet
These connect to a stud under the front sight on the rifle. The screw holds the outer locking sleeve onto the bayonet (compressing the spring)