With the aid of the following figures you will get all important information on different types of threaded connections.
Screws:
Cylinder head screw
Connection points:
IP 2: Top side of screw head
IP 1: Contact face of screw head
IP 3: Screw end
Countersunk screw
IP 1: Top side of screw head
IP 2: Bottom side of screw head
Stud screw
IP 1: Top side
IP 2: Bottom side
IP 3: End of screw-in thread
Threaded pin
Nuts
Nut
Connection point:
IP 1: Contact face
Cap nut
Washers / Rings
Washer
Ring
Holes
Through-hole with thread
IP 1: Material top side
IP 3: Material bottom side
Blind hole with thread
IP 2: Material bottom side
IP 3: Thread end
Through-hole with counterbore, flat resting
IP 1: Top surface of material
IP 2: Counterbore contact face
Through-hole for countersunk screw
IP 2: Counterbore end
Through-hole