In the steel structure machining welding structure, welding shrinkage and deformation will inevitably produce welding. Therefore, in the process of production, when the opening of the hole will greatly affect product accuracy.
I. Pole holes in the
steel structural parts are preferentially adopted. When proved the quality, thickness, and pores of certain materials, punching is permitted when punching will not cause brittleness. Drilling is performed on mechanical such as drilling machines, which can drill any thickness of steel structure components (parts). The advantage of drilling is that the wall of the bolt holes is less damage and the quality is better.
2. In the processing and manufacturing of steel structure, punching is generally only used to make non -round holes and thin plate holes. The pores must be greater than the thickness of the plate. The thickness is less than 12许 allowed to use punching. In the punching hole, welding (groove shape) shall not be subsequently applied. Unless the material is proven that the material is still very tough after the punch is cut, the construction can be welded. In general, when the holes need to be expanded on the holes you need to rush, the punch must be smaller than the specified diameter.
3. when the steel structure processing requirements are high, when the number of plate layers is large, and the similar holes are large, the method of drilling the mold or the small pore diameter of the pre -diamond can be used. At the time, the diameter of the pre -drilling small holes is less than the first level of the nominal diameter (3㎜). When the board is overlapped than the 5th layer, it is smaller than the nominal diameter secondary (6㎜).
