What Pre-Shipment Inspection Covers and Why It Matters<\/h2>\n
Pre-shipment inspection is the final stage of a layered quality-control system that includes:<\/p>\n
- \n
- Incoming Quality Control (IQC<\/strong>)<\/li>\n
- In-Process Quality Control (IPQC<\/strong>)<\/li>\n
- First Article Inspection (FAI<\/strong>)<\/li>\n
- Outgoing Quality Control (OQC<\/strong>)<\/li>\n<\/ul>\n
Each stage addresses different risks in the production chain.<\/p>\n
![\"Four-stage](\"https:\/\/ceshi.baoxuanmetal.com\/wp-content\/uploads\/2026\/07\/quality-control-layers-iqc-ipqc-fai-oqc-800x347.webp\")
The four quality control stages that cover sheet metal production from raw material to final shipment, with OQC (pre-shipment inspection) highlighted as the focus of this article.<\/span><\/p><\/div>\n
The pre-shipment inspection discussed here mainly refers to the final inspection or outgoing quality control performed internally by the factory. When performed by the customer or a third-party inspection agency, it is generally called a Pre-Shipment Inspection (PSI)<\/strong>.<\/p>\n
For customers, PSI is the last reliable checkpoint before manufactured parts enter their supply chain<\/strong>.<\/p>\n
Pre-Shipment Inspection Process: Step by Step<\/h2>\n
PSI follows a defined sequence. Skipping any step increases the risk of defective or nonconforming products reaching the customer.<\/p>\n
![\"Six-step](\"https:\/\/ceshi.baoxuanmetal.com\/wp-content\/uploads\/2026\/07\/psi-inspection-process-steps-flowchart-600x824.webp\")
The six sequential steps followed during a pre-shipment inspection, showing the full process from reviewing the inspection plan to releasing the shipment.<\/span><\/p><\/div>\n
Step 1 \u2014 Review the Inspection Plan<\/h3>\n
Quality inspectors begin by reviewing the sheet metal inspection plan<\/strong><\/a> together with the engineering drawings and purchase order (PO) to identify critical dimensions, tolerances, surface-finishing requirements and customer-specific standards.<\/p>\n
For parts with Geometric Dimensioning and Tolerancing (GD&T)<\/strong> requirements, the inspection plaackaging must account for the type of surface finish.n must also specify how each characteristic will be measured.<\/p>\n
Step 2 \u2014 Collect Production Records<\/h3>\n
Material certificates for the specified sheet metal materials<\/strong><\/a>, in-process inspection data and first article inspection reports are collected to establish the evaluation baseline.<\/p>\n
Step 3 \u2014 Select the Sampling Method<\/h3>\n
Production orders are generally inspected using an Acceptable Quality Limit (AQL)<\/strong> sampling plan based on ISO 2859-1.<\/p>\n
Prototype and low-volume orders are usually subject to 100% inspection<\/strong>, with every part measured and evaluated.<\/p>\n
Step 4 \u2014 Perform Dimensional and Visual Inspections<\/h3>\n
Measurements and surface evaluations are conducted according to the drawings, and all results are recorded.<\/p>\n
Step 5 \u2014 Verify Quantity, Packaging and Labels<\/h3>\n
The actual quantity is cross-checked against the packing list and PO. Packaging is verified according to the surface-finishing requirements, and every label field is checked.<\/p>\n
Step 6 \u2014 Prepare the Report and Release the Shipment<\/h3>\n
All inspection results are documented. Conforming parts are approved for shipment, while nonconforming parts are held pending a disposition decision.<\/p>\n
Dimensional Verification: Confirming Critical Measurements<\/h2>\n
For metal parts, dimensional verification is the most detailed part of the quality inspection process. Its main purpose is to confirm that every critical dimension falls within the tolerance specified on the drawing<\/strong>.<\/p>\n
Inspection equipment is selected according to the tolerance requirements. Tighter tolerances require more precise measuring instruments.<\/p>\n
<\/p>\n
![\"Digital](\"https:\/\/ceshi.baoxuanmetal.com\/wp-content\/uploads\/2026\/07\/dimensional-verification-caliper-sheet-metal-part-800x533.webp\")
A digital caliper taking a critical measurement on a sheet metal part during dimensional verification, with the tolerance requirement visible on the part sticker.<\/span><\/p><\/div>\n
<\/p>\n<\/p>\n
\n - In-Process Quality Control (IPQC<\/strong>)<\/li>\n
![\"Chart](\"https:\/\/ceshi.baoxuanmetal.com\/wp-content\/uploads\/2026\/07\/inspection-tool-selection-by-tolerance-800x373.webp\")
![\"Powder-coated](\"https:\/\/ceshi.baoxuanmetal.com\/wp-content\/uploads\/2026\/07\/common-surface-defects-sheet-metal-panel-800x533.webp\")
![\"Three-level](\"https:\/\/ceshi.baoxuanmetal.com\/wp-content\/uploads\/2026\/07\/defect-severity-classification-critical-major-minor-800x333.webp\")
![\"Open](\"https:\/\/ceshi.baoxuanmetal.com\/wp-content\/uploads\/2026\/07\/packaging-methods-surface-finish-pe-film-vci-bags-800x533.webp\")
![\"Close-up](\"https:\/\/ceshi.baoxuanmetal.com\/wp-content\/uploads\/2026\/07\/quality-documents-spread-coc-mtr-fai-report-800x533.webp\")
![\"Six](\"https:\/\/ceshi.baoxuanmetal.com\/wp-content\/uploads\/2026\/07\/shipping-label-verification-carton-closeup-800x533.webp\")