These are 0.1875 inch black oxide coated steel slotted posts. They are used for mounting sheath and holster attachments. Because they are slotted, they can be easily tightened or removed. Some users also like to reverse their mountings to make the attachment more secure. These will fit any screw with an 8-32 thread.
Specifications:
Slotted Post
Barrel length (under head): 0.1875 Inches
Barrel diameter: 0.200 Inches
Head diameter: 0.415 Inches
Thread: 8-32
Coating: Black Oxide
1 package = 10 slotted posts