Considering industry pressures, punch and die facilities can’t afford significant periods of machine downtime, not if they’re to remain a competitive force in an aggressively growth-oriented manufacturing sector. Unfortunately, as potent as these tools clearly are, they are susceptible to fatigue-related productivity bottlenecks. Any major disruption, whether due to a worn punch or a threadbare die assembly, will inevitably impact a machine shop’s bottom line.

Identifying Critical Manufacturing Chain Bottlenecks

Productivity slumps can make or break a punch and die operation. Hopefully, there are in-shop spares and a competent repair team on the premises. If slumps in output speed or a drop in quality-assured punch performance are experienced, the maintenance techs will quickly repair the declining system link before its failing parts can impact overall line yield. However, the metal stamping industry is as susceptible to premature wear as any other manufacturing sector. For one thing, the tools used to impart the stamps are situated at a manufacturing “crunch point.” Above the punch, a high-tonnage hydraulic press delivers huge quantities of kinetic energy. Then there’s the metal sheets and die, which absorb the brunt of the impact. Bottleneck number one, then, is the material that’s being stamped by the tool.

The Effects of Premature Wear In Punches

The punch tip, once sharply defined, blunts when early wear sets in; its clearly delineated profile has experienced more than its fair share of shock stress and loading impact. As insinuated earlier, the metal panel being fabricated here is maybe too thick, or the alloy is some exotic metal that resists indentations. If the tooling phase selects a hardened carbide or vanadium toughened alloy that’s not made out of a correspondingly fatigue-resistant alloy, then that tool, especially its tip, will blunt and disintegrate. Again, all tools age over time, but this premature wear isn’t normal. Sure to throw off a maintenance schedule or a die refurbishing program, the out-of-the-blue wear introduces an uncertainty factor into the process, so much so that the stamp shop experiences a nasty productivity slump.

A new level of preventative maintenance work is introduced, a level that exists solely as a means of identifying telltale punch and die wear indicators. To extend tool life, blunted and fractured tips are removed before they affect a quality assurance program’s reports. Burred edges and hole quality inspections are added to the checklist. Chamfered and bevelled hole features are inspected, too, perhaps to see if they’re clean and smooth. Galling incidents, frictional tool heat, press stroke noise and more, all of these wear indicators must be flagged by the maintenance techs so that a repair strategy can be put into effect before a productivity bottleneck develops.