1、 Material quality control Metal material Composition testing: Ensure that the steel meets the standards, and detect the content of carbon, chromium, nickel and other elements through spectral analysis to avoid corrosion or insufficient strength caused by material problems. Thickness uniformity: Use an ultrasonic thickness gauge to measure the thickness of the board, with an error controlled within ± 0.1mm to prevent local weaknesses from affecting load-bearing capacity. Auxiliary materials Sealing strip: Choose silicone or rubber materials that are resistant to aging and corrosion, and test their compression rebound rate (≥ 40%) and temperature resistance range (-40 ℃ to 120 ℃). Lining fabric: It needs to pass flame retardant testing (such as the US CFR 1633 standard) to ensure no harmful substance release (such as formaldehyde content ≤ 0.05mg/m ³). 2、 Process precision control procedure Weld strength: TIG or MIG welding is used, and the weld must undergo tensile testing and dye penetrant testing to detect cracks or porosity. Deformation control: After welding, stress is eliminated through vibration aging or heat treatment to ensure that the flatness of the coffin body is ≤ 1mm/m. Bending and Forming Angle accuracy: When using a CNC bending machine, the bending angle error should be ≤ 0.5 ° to avoid assembly difficulties caused by angle deviation. Edge treatment: All cutting and bending edges must be polished to R0.5mm or above to prevent scratching operators or customers. 3、 Safety and functional design Load bearing and stability Bed frame load-bearing capacity: The steel bed needs to pass a static load test (load-bearing capacity ≥ 300kg, no deformation for 24 hours). Anti slip design: Anti slip silicone particles are added to the bottom of the mattress to prevent sliding during transportation. Sealing performance Waterproof test: Immerse the coffin body in a 1-meter deep water tank for 24 hours, with an internal humidity change of ≤ 5% RH. Airtightness: Passed positive pressure test (inflated to 500Pa, pressure drop ≤ 50Pa/10 minutes). 4、 Production Management and Quality Control process monitoring SPC statistics: Implement statistical process control for key dimensions such as weld width and coating thickness, with a CPK value of ≥ 1.33. First article inspection: First article inspection must be completed before each batch of production, and batch production can only be carried out after confirmation of qualification. Finished product inspection Full inspection items: including appearance defects (scratches, dents), functional testing (hardware opening and closing, sealing), and packaging integrity. Sampling standard: Conduct AQL sampling according to ISO 2859-1 standard, with a general defect AQL of 2.5 and a severe defect AQL of 0.65. 5、 Customer customization and after-sales service Customized requirements Size and color: We provide customized non-standard sizes (such as length ± 10cm), and colors support Pantone color card matching. Personalized engraving: Laser engraving accuracy needs to reach 0.1mm, supporting customization of text and patterns.