[China Aluminum Industry Network] First, the quality inspection of the ingot The appearance of aluminum alloy ingots is not allowed to have cracks, bubbles and corrosion mottled appearance, the appearance should be clean, no oil and dust, not allowed to have flashes, burrs and metal tumors 1mm above the base surface. There should be defects such as pull marks, layering (cold septa), and shrinkage holes that are not more than 1. 5 mm deep. Inspection of the appearance quality of the aluminum alloy ingot is visually checked, and each aluminum rod should be inspected. Second, the size of the ingot inspection error The dimensional errors of round ingots used for extrusion of aluminum alloys are shown in Table 6-1. Sampling rule: 10% per furnace, but not less than 2. Table 6-1-9 Scaling Errors for Commonly Extruded Round Ingots Round ingot diameter /mm Diameter acceptance error /mm Length tolerance /mm Bend/mm Face cut /mm Per meter full length Φ265 Φ203 Φ178 Φ165 Φ120 Φ90 ±2.5 ±2.0 ±2.O ±2.0 ±1.5 ±1.O ±4 ±4 ±3 ±3 ±2 ±2 <4.5 <4.1 <3.7 <3.6 <2.8 <1.7 - <15 <15 <15 <15 - <5.0 <5.0 <4.5 <4.5 <4 <3 Inspection method: Use a 0 to 300 mm vernier caliper to measure the diameter of the circular ingot and use a metre to measure the length of the ingot. Using a calibrated ruler, lean on the round ingot in the direction of the length of the round ingot, and use a vernier caliper to measure the larger gap between the ruler and the round ingot, which is the degree of curvature of the round ingot. The sight point ruler is used to rest on the end face of the round ingot, and the larger gap between the sight-point ruler and the end surface of the round ingot is measured with a vernier caliper, which is the cut-off degree of the end face of the round ingot. LED Exit Light ,Emergency Exit Light,Illuminated Exit Signs,Led Exit Signs NINGBO JIMING ELECTRIC APPLIANCE CO., LTD. , https://www.jimingemergencylight.com