The inspection of sheet metal equipment bases must strictly adhere to the standards and specifications of four core dimensions: appearance, dimensions, performance, and structure.
Appearance Inspection: This mainly focuses on surface treatment, process details, and raw material defects:
Surface Treatment: Electroplating or oxide layers should be smooth, uniform in color, and free from spots, scorching, cracks, peeling, yellowing, or uneven coloring.
Process Details: All edges must be smooth and free of burrs and sharp corners; the surface should be free of obvious dents, protrusions, twisting, or deformation; welds should be uniform and smooth, free of slag, incomplete welds, or missed welds.
Material Defects: Inspect raw materials such as steel plates, square tubes, and nuts for rust, cracks, indentations, and other defects.
Dimensional Inspection: Precise measurements must be taken using tools such as calipers, tape measures, and height gauges to ensure compliance with drawing tolerances (typically ±1mm):
Key Dimensions: Measure external dimensions (height, width, depth) and internal clear space dimensions to ensure compatibility with standard 19-inch equipment.
Square Hole Strip: Check the hole spacing (1U=44.45mm), hole diameter, thread specification (e.g., M6), and tap depth to ensure all holes are aligned.
Foot/Cassette Casters: Their adjustment range must meet design requirements.
Performance Inspection: This is crucial for evaluating the durability and safety of the base, including multiple physical and chemical tests:
Basic Physical and Chemical Properties: Hardness ≥5H, Impact Height ≥500mm, Adhesion ≥ Grade 0.
Corrosion Resistance: Must pass tests such as the Neutral Salt Spray Test (NSS), with both protection and corrosion resistance grades not lower than Grade 10.
Other Properties: Mildew resistance grade not lower than Grade 0; Antibacterial rate ≥99.58%; If used in public places, its combustion performance must meet requirements such as peak heat release rate ≤2.9KW.
Structural Inspection: Primarily verifies the assembly accuracy and overall geometric tolerances of the base:
Verticality: The verticality between the frame column and the base should be less than 1.5mm.
Parallelism: The parallelism between the top frame and the base should be less than 1mm (this can be relaxed to 1.5mm if there is a partition).
Diagonal difference: The absolute value of the difference in diagonal length between the upper and lower frames should be less than 1.5mm.