Methodical Problem Solving—What Every Tooling Engineer Should Know
June 6, 2025Comments
Stamping dies experience an array of stresses, temperatures, chemicals, shock and vibrations. Thus it is not surprising that metal stamping dies are prone to all kinds of in-process failures.
The premature failing of tooling components demands a complete analysis and proper identification of the failure mode(s) in order to repair the tooling properly and maintain optimum performance. Unfortunately, the immediate response to many failures involves repair or replacement of the damaged component as quickly as possible so that production may resume. Time-pressure conditions often preclude a properly devised investigation, which can result in important evidence being discarded or destroyed.
Although the sequence may vary depending on the failure type(s), the procedure for any failure analysis should include the following steps.
Set aside biases. Unconscious bias is triggered by our brain automatically making quick judgments and assessments. Our background, training, personal experiences and cultural perspective all influence our biases. For example, a diemaker may view every stamping-related problem as a tooling issue, primarily due to how they were trained and the corporate culture in which they trained. This may lead diemakers to dismiss the opinions of others who have not undergone similar in-depth training.
Collect samples. The failed die component (broken, twisted, bent, galled, chipped, scored, etc.) is the primary failure sample because it contains the actual failure site. A sample part of a similar component which has not failed, preferably one that has run successfully in production, also is desirable. Or, for replacement parts produced in batch lots, take a sample from the replacement-parts bin for comparative analysis. Comparing a failed component with one that has not failed proves beneficial in assessing if a failure occurred due to service conditions or to an error during manufacture.
Visually examine the failed part. Design errors often contribute to die failure. Design errors can be classified into two basic groups: those that fail from heat treatment, and those that fail in service.
Design faults that cause failures from heat treatment include the presence of thick sections adjacent to thin sections; sharp corners; blind holes; stamp marks; corner radii that are too small; poorly located or designed grooves and notches; abrupt changes in cross-section; and the location of holes that result in thin walls.
Compile background data. Time spent collecting background data is vital to the success of any failure analysis. Necessary steps include a thorough understanding of the entire manufacturing process, the service histories of the failed component(s) and the reconstruction of the sequence of events leading to the failure.
