1. The head should be round (this is also the common st […]
1. The head should be round (this is also the common standard for all round head screws). Due to the production process, the drywall screw heads produced by many manufacturers may not be very round, and some may even be slightly square. The problem is that it can't be completely matched with the gypsum board after screwing in. Concentric circles, rotating around a central point, this should be well understood.
2. The tip is sharp, especially when it is used on a light steel keel. The sharp corners of the drywall screws are generally required to be between 22 and 26 degrees. The sharp corners of the head are required to be full, and there is no possibility of dragging or cracking. This "tip" is the most important for dry-walled Ruth, because the use of dry-wall screws does not hit the pre-made holes, and is directly screwed in, so the pointed end also bears the function of drilling through. Especially when used on light steel keels, bad tips can cause the drill to not enter, directly affecting the use. According to national standards, wall panel screws should be able to drill through 6mm iron plates in 1 second.
3. Can not be eccentric. The easiest way to determine if the drywall screws are eccentric is to place the round head down on the table to see if the threaded portion is vertical and is in the middle of the head. If the screw is eccentric, the problem is that the power tool will shake when it is screwed in. The short screw is good. If the long screw touches this situation, the trouble will be big.
4. The cross recess should be in the center of the round head, otherwise it will be the same as in the case of 3.