What are the Best Practices for Progressive-Die Maintenance?
When it comes to die maintenance, the proper standard response is below,
Review all the cutting sections for wear and sharpen as needed. Check all the pilots and replace if worn. Review all the form punches and dies and replace if there is any measurable wear. Check the lifters and springs and replace as needed. Check the timing on all the inserts.
This is what many tooling managers would expect to hear, and in fact these items are required. But is this what we are looking for when we talk about maintenance best practices?
When maintaining any process, it is best to first understand the end goal, then fill in the tasks When maintaining a progressive die, the three primary end goals are:
Identify, measure, and assess every area of the tool that will degrade over time. The key here is not to overlook any areas of degradation. Two oversights are very common: We fail to capture every item that will degrade over time, and we make judgments on items that will not affect part quality. As a result, areas of degradation are overlooked because we assume that they have no effect, which ultimately yields inconsistent hits per service and part quality off the tool.
What is the procedure for servicing the areas of degradation? For example, how much do you grind off the punch and die when sharpening? What polishing tool and media do you use to polish the forming inserts? Which tooling dimensions need to be checked, and to what tolerances? With this huge area of variation, you need a guide to ensure each service tech does things the same way to get the same results. You cannot adjust or improve on an inconsistent process.Continuous improvement does not start until you have captured all the wear items and have a documented, consistent way to maintain them. The results must be measurable and consistent. You should be able to take part measurements off the stamping die with minimal accepted variation defined and controlled using statistical process control (SPC). In addition, your hits per service should be consistent from run to run, and component replacement should have no effect on the part quality.
- Continuous Improvement
Once you’ve achieved consistent, measurable results, you can begin the final leg of the best-in-practice maintenance policy. What can be improved upon? What can you do to improve the robustness of the tool? How can you address areas of the tool that are yielding the greatest variation and improve tooling life? What can you do to increase stamping speed and throughput? Perhaps a new steel or carbide would improve hits per service. A new coating might reduce wear.Continuous improvement is an absolute requirement in which SMART (specific, measurable, attainable, relevant, time-bound) goals should be documented and tracked. Remember, if you are not improving, you are, in effect, losing ground as a result of your competition moving forward.