Countersunk screws are also called countersunk screws, also known as flat machine screws, and are a type of construction part. The head is a 90-degree cone, similar to common wood screws, with tool tightening slots on the head, including flat, cross, hexagonal, plum blossom, pentagonal, etc.
Screws such as duplex 2205 countersunk head socket screw are used to connect two objects. Generally, the head of the screw protrudes above the surface of the connected object, making the surface uneven. Countersunk screws can sink under the surface to make the surface flat. Harder objects need to drill countersunk holes at the corresponding position of the countersunk head. In short, the countersunk head means that the head of the screw can keep the surface flat after installation.
| All Material for the bolts | ||||
| Hastelloy C276 | Duplex 2205 | A193 B8 | SS304 | Inconel600 |
| Hastelloy C22 | Duplex S31803 | B193 B8M | SS316 | Inconel601 |
| Hastelloy C4 | Super duplex S32750 | Alloy59 | SS316L | Incoloy718 |
| Monel400 | Super duplex 2507 | Alloy20 | Stainless steel 18-8 | Incoloy800H |
| Monelk500 | 904L | 309S | SS321 | Incoloy800 |
| Nimonic 80A | Alloy 926 -UNS N08926 | 310S | 317L | Incoloy825 |
On the surface of the mounting hole on the connector, there is a 90-degree conical round socket. The head of the flat machine screw is in this round socket and is flush with the surface of the connector. Flat machine screws are also used in some occasions. Semi-circular flat machine screws are more beautiful and are used in places where a little protrusion is allowed on the surface.
Screws play the role of connecting two or more objects and are an indispensable necessity in daily life or industrial manufacturing. There are countersunk bolts (with grooves) and countersunk bolts (with tenons).
Notes
- The taper of the hole should be 90°. It should be guaranteed. It is better to be less than 90° than to be greater than 90°. This is a key trick.
- If the thickness of the sheet metal is less than the thickness of the countersunk screw head, you can change to a smaller screw, or you can expand the hole smaller rather than expand the bottom hole diameter to make the parts not tight.
- If there are multiple countersunk screw holes on the part, you should be more precise during processing. Once the drilling is crooked, it will be ugly when assembled, but as long as the error is not large, it can be tightened. Because when tightening, if the diameter of the screw is not very large (about no more than 8mm), when there is an error in the hole distance, the screw head will be deformed due to the force when being tightened, but it will still be tightened.
