The flat head screw has a screw body. An axially extending screw thread is formed on an axial surface of the screw body, and at least one cutting groove is provided at a tail end portion of the screw body. The notch above the cutting groove is further toward the screw body. A flutes are dug in the center, and the flutes are deep inside the screw body and exceed a predetermined angle beyond the centerline of the screw body, so as to prevent the chips from blocking the notch.
flat head screw
The axial surface of the screw body is formed with axially extending threads and at least one notch is formed at the trailing end. In the notch to the center of the screw excavation a flutes, flutes deep into the screw body and beyond the center line at a predetermined angle, the main role is to avoid chip blocking cut slot.
Countersunk head screws
The head of the screw is a 90-degree cone, and the head has a tool tightening groove with a slot, a cross slot, a hexagon socket, a plum blossom slot, and the like.
Flat head screw pictures
Flat screw effect
On the surface of the mounting hole in the connector, a 90-degree conical socket is machined. The head of the flat screw is in this socket, flush with the surface of the connector. Screws for flat machines are also used in some occasions with semi-circular flat-head screws, which are aesthetically pleasing and are used to allow the surface to protrude slightly.
Screws play a role in the connection of two or more objects and are indispensable for daily life or industrial manufacturing.
Countersunk head bolts (with grooves), countersunk head bolts (with burrs)
Flat head screws
Countersunk head screws are mostly used after installation. The surface of parts can not be raised. There are two kinds of fastening parts: thick and thin, that is, the thickness of the parts to be fastened is greater than that of the countersunk head screws. Thickness, after the screw is tightened, there is still a portion of the screw thread that does not enter the threaded hole. In this case, countersunk screws can be tightened. Usually there is also a situation where the thickness of the part to be fastened is less than the height of the head of the countersunk head screw. This is common in sheet metal parts in mechanical equipment, such as the hinge of the chassis and the connection of the door and the box; the sheet metal of the equipment Coupling of enclosures and equipment, etc. Due to the small thickness of the part, the screwed metal part, the screw hole, is completely formed into a conical hole. In this case, when the countersunk head screw is tightened, the head of the screw does not press the sheet metal face with the taper. Instead, the bottom of the screw head and the top of the screw hole are squeezed. Although it is felt that the screw is tightened, the sheet metal part is stuck instead of being pressed. In this case, although the screw is felt to be tightened, Gold does not have to be tightened. This is a very common situation.
Let's talk about the reason for processing: The head cone of the countersunk head screw has a 90° cone angle, and the angle of the top corner of the newly purchased drill is usually 118°-120°. Some workers who lack training do not know this angle difference at all. It is often used directly with a 120° drill bit to expand the hole, which causes the countersunk head screws to be tight but not a conical head. It is a line at the bottom of the screw head, which is also one of the reasons why the countersunk head screws cannot be fastened