Weld Butt Joint Dimensions for Low Alloy Steel Electrodes (GB / T 5118-1995)
Butt joint welding is a common form of welding in which two members, usually two pieces of metal, are joined end-to-end along their edges. This type of welding is used in many industrial and engineering applications, and the dimensions of each butt joint weld must adhere to specific requirements. In China, weld butt joint dimensions are specified by the national standard GB / T 5118-1995.
This standard applies to welding of low alloy, low carbon and alloying steel materials. It’s applicable for both manual and mechanized welding processes and can be used for both butt and corner joints. The standard outlines the requirements for weld toe and root gaps, edge preparation, weld joint alignment, and more.
For weld toe and root gaps, GB / T 5118-1995 specifies that the gap should be from 0.6 to 1.0 times the material thickness of the welding joint. The gap should also not exceed 3.2 mm for butt joints and 4.2 mm for corner joints.
When it comes to edge preparation, the standard requires that the edges of the joint must be ground (or “featheredged”) at an angle of ≤3° and the edge should be ≤1.2 mm. The welding tolerance should generally not exceed 0.8 mm, and the welding gap should not exceed 4 mm.
For weld joint alignment, the gap should be checked and verified with a welding stick and should have a range of 0.5-1.5 mm. When preparing for welding, the gap should also be properly adjusted to ensure a sound and uniform bead.
GB / T 5118-1995 also addresses other areas of welding including preheating, post weld heat treatment, and welding consumables. Each of these areas should be considered prior to beginning the welding process.
Overall, the requirements outlined in GB / T 5118-1995 ensure high-quality butt joint and corner welds that are suited for low alloy steel applications. It’s important to read and understand the requirements in this standard prior to beginning the welding process to ensure the highest quality welds.
