Avoiding defects is a major goal in metal stamping. Over time, machinery needs recalibration, and punches and tools need sharpening or realignment. If these issues are ignored, stampings may drift out of tolerance, leading to extra time and money for rework.
Your stamping partner should value quality control as much as you do. At Keats Manufacturing, we are always watching for defects and out-of-tolerance stampings during manufacturing and with specialized inspection methods. Keep reading to learn more.
Defect Rates
In small production runs, it’s often possible to inspect individual stampings manually – this is not so much the case at high volumes. Defect rates can soar if problems are not fixed early. Stampers turn to inspection methods that use computers and automation to find defects and errors while maintaining efficiency.
One option is coordinate measuring machines or CMMs. These devices use delicate probes or vision cameras to physically or optically assess a part’s dimensions and features. By comparing the part against stored coordinate data or a digital image, CMMs identify when a part is out of tolerance.
To speed up the process, specialized fixturing is used to position multiple parts for inspection at once. This helps operators maintain their workflow while incorporating quality control.
Forming and Dimensional Defects
Forming and dimensional defects can occur as a result of the material used, worn or improperly assembled tooling, or design problems like defect-prone part features or specifications that are challenging to achieve.
Defects or problems that appear repeatedly signal a stamping error. Identifying and resolving them quickly makes it easier to avoid scrap and rework and minimizes the risk of defective parts reaching you or your customers.
Forming Defects
Metal forming is the process of changing the shape of a metal workpiece without adding or removing material. Common examples of forming defects include:
- Cracking and tearing
- Galling or scratching
- Misalignment or shifting inside the press
- Incorrect punch or guide angles
Dimensional Defects
Metal stamping involves changing the shape of a workpiece by cutting, punching, shearing, blanking, or otherwise removing material to create a finished part. Defective parts are often out of tolerance, which affects their fit and function in an assembly or finished product.
Common sheet metal stamping defects include:
- Twisting, wrinkles, or improper flatness
- Incorrect hole placement, size, or shape
- Incorrect bend angles or springback
- Burrs and deformed edges
- Overall part length/width defects
Stamping defects are often caused by a misaligned material feed, worn or broken punches, material defects, improper force or tonnage, or other problems.
Packaging Defects
Packaging mistakes can also lead to damaged parts, scrap and rework, fulfillment delays, and extra expenses.
Incorrect or Missing Shipping Markings and Barcodes
Incorrect barcodes or labels in the wrong place are inconvenient in smaller orders, and it only compounds in a high-volume production run. It takes time and money to relabel dozens or hundreds of boxes and cases, or to recheck part numbers, shipping info, or dimensional details. That in turn causes fulfillment delays, so it’s critical that inspection includes checks for these errors.
Container and Product Defects
Components may be packaged manually by workers or with automated or semi-automated equipment, or even a combination. Regardless of the method, parts can be damaged if they are packed incorrectly, jostled and scratched, or if the packaging itself is damaged, bent, or torn. Some packaging methods like tape and reel encapsulation for very small parts, or custom trays to isolate individual parts, can prevent damage during packaging.
Another important step is the final inspection of packed parts. This ensures packaging is correct and no defective parts were missed in earlier inspections. It can be done by workers as they pack items or with machine vision equipment, comparing an image of a correctly packed tray or box with items as they exit the packaging line.
Metal Stamping Services From Keats Manufacturing
Errors and defects can happen at many points in the stamping and packaging process. That’s why you should work with a manufacturer who prioritizes attention to detail at every turn and has taken the steps to mitigate the risk of defects.
At Keats Manufacturing ee are ISO:9001, ISO:14001, and IATF:16949 certified. We provide high-quality metal stamping and finishing services with careful inspection and packaging to meet your needs. Contact us to learn more or request a quote to start your order.