bm fasteners, German bm models, bm prices

bm fasteners feature one or more cutting slots at the end of the thread, allowing them to cut matching internal threads in a manner similar to a tap when screwed into a pre-drilled hole, utilizing the screw tail and threads. They can be used on thick plates and materials that are hard, brittle, or difficult to form. Self-tapping screws are screws with a drill bit tip; using specialized power tools, drilling, tapping, fixing, and locking are completed in one operation. Self-tapping screws are mainly used for connections such as joining color steel sheets to each other and fixing them to purlins. These self-tapping screws are often exposed outdoors and possess strong corrosion resistance; their rubber sealing rings ensure no water seepage at the screw location and provide good corrosion resistance. Self-tapping screws are typically described by three parameters: screw diameter grade, number of threads per inch, and shank length. The corresponding screw diameters have three grades for the number of threads per inch; the higher the number of threads per inch, the stronger the self-drilling capability.

bm fastener basics

Generally refers to self-tapping threads that perform a self-tapping action and do not require a nut. Screw heads come in many classifications, including external hex, pan head, countersunk head, internal hex, umbrella head, and head with washer, among others. The tail is generally pointed to enable the self-tapping action. Self-tapping screws are also called self-tapping screw fasteners. The primary advantage of self-tapping screws is that they do not require nuts, resulting in significant cost savings by eliminating nut costs. There are many commonly used self-tapping screws, such as cross-recessed pan head self-tapping screws, countersunk self-tapping screws, self-tapping screws with washers, umbrella head self-tapping screws, cut-tail self-tapping screws, and the triangular thread self-locking screws mentioned in a previous post. Triangular thread self-locking screws are widely used in the market and by customers.

bm fastener surface treatment

Self-tapping screw surface treatment: Most self-tapping screws are coated with zinc plating or zinc phosphate coating. Cadmium plating is rarely used due to its high cost and toxicity; if appearance is important, nickel or chrome plating can be selected. When testing applicable pilot hole diameters, the screws used must have the same surface treatment. To penetrate iron plates, self-tapping screws must undergo carburizing treatment. Carburizing results in high hardness and high carbon content, which can cause hydrogen embrittlement during electroplating or pickling treatments. The thickness of the flat washer or spacer under the head bearing surface should match the maximum effective thread length of the screw. For long screws with partial threads, the shank can be supported by longer cold-rolled steel spacers or flat washers to ensure the fully threaded section engages and remains within the test iron plate thickness.

bm fastener types

Based on the development and evolution of self-tapping screws, we consider that the main types of self-tapping screws are as follows: standard self-tapping screws have "self-tapping threads", also known as "wide-pitch threads". The surface is mostly electroplated. Self-cutting self-tapping screws are referred to as "self-tapping screws with scraping end", with self-tapping threads or machine screw threads, and the cross recess is also "H" type. Self-cutting self-tapping screws come in the following forms: cross-recessed pan head self-cutting self-tapping screws, cross-recessed countersunk head self-cutting self-tapping screws. The shank cross-section of self-tapping screws is triangular. Therefore, they are also called triangular thread screws. Standard self-tapping screws, self-cutting self-tapping screws, self-drilling self-tapping screws, etc., combined with flat washers and spring washers (including spring washers and elastic locking washers) form t assembled self-tapping screws. In short, there are many types of self-tapping screws. With the development of production, advancements in technology, new materials, new structures, and new thread forms, new types of self-tapping screw products will continue to emerge.

Weidou Intelligent Technology specializes in selling German bm bolts, bm studs, bm screws, bm nuts, bm self-tapping screws, bm washers, bm shims, bm lock washers, bm safety washers, bm locking washers, bm lock shims, bm safety shims, bm locking shims, bm retaining rings, and bm pins. bm products are original imports from Germany. We welcome inquiries and orders from customers.