The process used when fastening to concrete has basical […]
The process used when fastening to concrete has basically remained unchanged over the years. Although there are epoxy/chemical type anchors in use today, the majority of anchors rely on the same principles that were developed many years ago.
Fastening to concrete is unique compared to other fastening applications, such as fastening two pieces of metal together by using a screw or a bolt and nut. Concrete anchors of any type are much more difficult to use and install correctly.
The concept of fastening something to a solid base material is completely different than for almost any other type of fastening application. Concrete is the most widely used base material in the world for the last 2,000 years and probably will remain so for the next 2,000 years due to its simplicity, strength, versatility and the abundance of the ingredients used to make it.
Concrete screws are different than all the rest of the anchors because they do not use expansion to derive their holding values. Concrete screws are a special threaded screw, with hardened notched threads and high-low threads. The notches and the high low threads help to eliminate concrete shavings from the hole as the screw taps threads into the base material. The hole size for concrete screws is smaller than the diameter of the screw. A 3/16" screw requires a 5/32" hole and a 1/4" screw requires a 3/16" hole. The concrete screw is inserted into the hole and turned either by hand or by a rotation drill until the concrete screw is tight against the fixture being fastened.
Machine screw anchors are a female type anchor into which a threaded item is placed. Machine screw anchors are made up of two parts, the internally threaded cone and the sleeve. The sleeve is place over the threaded cone and inserted into a hole drilled in to the base material of concrete, brick or block, threaded cone first. The machine screw anchor is set by the sleeve being pushed over the expander sleeve wedging the sleeve between the expander sleeve and the inside wall of the concrete. The anchor is properly set when the lip of the setting tool meets the lip of the anchor. Each diameter machine screw anchor has a specific setting tool that is designated by the diameter of anchor being used. The machine screw anchor size is designated by the inside diameter of the bolt to be used with the anchor, the hole size required is larger than the anchor size being used.
Find the right din975.net thread size: The size of the nylon thread makes a difference to an application. If a rod with a wrong thread size is used, it will not fit with the threads of the nut and will have to be replaced. If the rod is forced into a tapped hole, it may cause cracks or weaken the rod at a later stage.