Understanding Manufacturing Equipment

Using Dimensional Inspection To Ensure Parts Are Accurate

by Tomothy Perez

If you are manufacturing parts or items that need to have extremely tight tolerances, the best way to ensure the item's accuracy is to send it to a dimensional inspection lab for verification. Using a lab to check random parts in the run to produce an unbiased sample is often required in industries where parts or products have extremely slim margins for error.

The Purpose Of Dimensional Inspection

In the simplest terms, dimensional inspection is a verification process that involves an inspector going over a part or item to check every dimension on it against the design or engineering drawing to ensure the piece matches the requirements. Sometimes, the inspector will work in a third-party dimensional inspection lab or work in-house for the manufacturer. Still, in both cases, the inspector is responsible for flagging any part or item that is not accurate.

Many manufacturing companies use an inspector to check parts at random. The inspector is the one person not involved in the manufacturing process that can shut down the manufacturing line if they find an error. Critical components need to be inspected multiple times a day, so many large manufacturers will set up a dimensional inspection lab in the facility.

The lab may be run by a third-party to ensure there is no bias in the inspection process, but having the inspector there to pull parts from the line and go over them randomly can significantly reduce an overrun of components that are out of spec.

Dimensional Inspection Reports

All inspections by the dimensional inspection lab are recorded, and a report is created to document any issues that come up. The reports can be critical for the manufacturer because they show problems on the part or item coming off the line and allow process engineers to correct the problem. 

Large manufacturers will often shut a product line down based on the report, so it must show the issue clearly and precisely. The lab tech creating the report will often use a drawing of the item and indicate problems on the picture that show engineers what is off and how much. 

If the parts are CNC machined or created on automated equipment, the program may need to be adjusted to correct the variance. If the items are made by operators running specific equipment, the process may need to be reviewed to see where the problem is so that the way the part is made can change or be adjusted. 

Large manufacturers depend on this process to ensure that their processes are working correctly and they are producing a part that is accurate and will function properly for the customer.

For more information, reach out to a dimensional inspection lab in your area.