Mild Steel Tubing (1010)
The term "mild steel tubing" refers to tubing that has been produced by the electric resistance welding (ERW) process. It is provided in the state in which it leaves the welder, with only minimal downstream processing such as stress-relieving or annealing to meet particular customer specifications. The lack of additional processing such as cold drawing makes as-welded tubing a cost-effective product for many mechanical applications.
It is produced in a wide variety of sizes with close tolerances that allow the tubing to be used in mechanical parts with little or no metal removal or machining. Some of the principal benefits you can expect from as-welded tubing in mechanical applications:
Chromoly is an abbreviation for "chromium-molybdenum steel". It is not as lightweight as some steel alloys, but has the advantages of high tensile strength – 90-95 ksi [ksi = 1000 pounds per square inch] in the normalized condition – and malleability. It is also easily welded and is considerably stronger and more durable than standard (1020) steel tubing.
Chromoly is often called "4130" because the carbon content is nominally 0.30%. With this relatively low carbon content the alloy is excellent from the standpoint of fusion welding . The alloy can be hardened by heat treatment or "normalizing". This is a process of taking 4130 tube up to a prescribed temperature and cooling it at a precise rate. This removes all strain created in the tube manufacturing process and allows the homogenization of the steel's grain structure.
Here are the principal benefits you can expect from Chromoly tubing in mechanical applications:
DOM (Drawn Over Mandrel)
DOM refers to high-strength, electrically-welded tubing that has been further processed by cold drawing through dies and over mandrels to improve its uniformity, mechanical properties and surface finish.
To a great extent, DOM tubing is customized to each specific application. This provides further advantages, particularly to high-volume manufacturers. They include a wider range of sizes and tighter dimensional tolerances that allow the tubing to be used in mechanical parts with little or no metal removal or machining. Because of its many advantages, DOM is the material of choice in many of the most demanding applications for tubing, including: hydraulic cylinders, auto and truck components, recreational vehicles and others.
The manufacturing process for DOM tubing begins with coils of steel, which are slit to the proper width for the desired tube size. The strip is cold formed and passed through an electric resistance welder which joins the edges together, under pressure, to complete the tubular shape. After testing the weld's integrity, the tubing is cut to length for further processing.
The cold-drawing process creates a uniform, precision product with substantially improved tolerances, surface finish and tensile strength, increased hardness and good machinability. In this process, the tube is cleaned and annealed, and one end of each length is squeezed to a point so it can be gripped by the drawing mechanism. The tube is then drawn through one or more dies and over mandrels. This reduces the diameter of the tube and thins its walls to the required dimensions in a controlled fashion to provide the qualities desired in the finished product. Metallurgically, drawing improves the tube's concentricity, tensile strength, hardness and machinability. Close dimensional accuracy is achieved through tight control of both outside and inside diameters.
Here are the principal benefits you can expect from DOM tubing in mechanical applications:
The term "Standard Pipe" refers to steel pipe manufactured for use in a wide variety of applications that require strength, durability and ease of fabrication. Because of its many advantages, Standard Pipe is the material of choice in such diverse applications as conveying fluid and gaseous mediums, water wells, fencing, foundation pilings, building and bridge construction and many others.
Products are produced in a variety of steels including carbon and alloys, galvanized, weathering and HSLA and to meet various ASTM, API, government and customer specifications. Pipe can be supplied with several different types of ends---threaded-and-coupled, beveled or grooved.
Three principal processes - electric resistance welding, butt (continuous) welding and seamless - are used in the manufacture of Standard Pipe.
Here are the principal benefits you get from Standard Pipe:
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