Design and build molds to inch or metric

The U.S. is one of the few countries in the world still designing and building molds to inch standards when the global standard for measurement is metric. By using the inch standard our industry is out of sync with the rest of the world (except Liberia and Burma). This became clear early on in my career when I was working on an over-cap for a shaving cream container, whose product drawing was in metric with a 38mm overall diameter. My first thought was to stick with the metric, but as a junior engineer I needed to seek help from a senior designer. One look at the layout provoked a critical question: “What the %#&** is this? Son, we don’t do things like this. You need to convert the part drawing into inch dimensions and then we can talk.”

That was 1990 when there were unlimited tooling opportunities for U.S. mold manufacturers. Advance 23 years and see a mature tooling market whose opportunities must be hard fought. Most U.S. mold manufacturers only look domestically and ignore the European market where much opportunity for new business awaits them. However, a key requirement for selling molds in Europe is fluency in the metric standards. Making the metric change cannot only open your shop up to other markets, but also improve its efficiency. By adopting the global standard we can simplify inventory, increase purchasing power (many metric components are less expensive) and work with simpler numbers with global fits and tolerances.

Establishing the Need for Metric
Fast forward to 2008 and I am now working for a German company with operations in the U.S. When they entered the U.S. market the decision was made to develop and offer standard inch mold bases with its standard leader pin system. The market was there for this product in the nineties and early 2000s, but then came the slowdown of 2007. In 2008 the company decided to no longer offer inch mold base sizes. At this point, I was head of sales and needed to produce a plan to sell metric in an “inch” market.

How was I going to accomplish this? I began to examine our U.S. market and noticed that we were selling metric mold bases. Who was purchasing these? It turns out that BMW and other European companies were requesting their mold suppliers design and build their molds to metric standards for consistency. This was a good start, but I was tasked with growing the market, so I created a spreadsheet to compare standard inch sizes with standard metric sizes (see Table 1). This helped illustrate just how close the two systems are—but close is not good enough when it comes to the precision work of moldmaking. Going metric will not require drastic changes; only an understanding of the new sizes and committing to them.

Next, I examined what effect pushing the metric standard would have on the U.S. moldmaking marketplace. I discovered that many U.S. shops are partially working in metric. Some make parts for European customers and build molds that make parts to metric sizes, but the bores and plate sizes are the U.S. inch standard. Other shops are required by customers to use the metric standard, only to convert all the metric sizes to inch sizes for manufacturing.

I also thought if a European company presented a substantial mold package to a major U.S. mold shop—with the stipulation that it be designed and built to metric standards— it would most likely not be turned down. However, I wondered how comfortable this European company would be with a shop that had never used metric standards before, but was all tooled up and ready to go.

Planning and Promoting the Move
With all of this information, I developed a plan to actively promote to moldmakers, with whom I was familiar, the switch to the metric standard: educate the industry on (1) the simplicity of the metric standard, (2) the economic advantages of working with the global standard, and (3) address the fear of change.

The first group to target was designers addressing the need to understand the standard metric sizes for mold bases, etc. and then move on to pocket and bore sizes, and pitch spacing. Once this was complete, we could work on manufacturing for which we needed to require some metric tools (a 0-25mm micrometer vs a 0 -1”). Then switch the readouts on the machines to mm. Educating management on the metric advantages was next.

I also enlisted the help of a former colleague who also believed in the metric standard and actually conducted training in this realm. He conducted research on the subject of metric in U.S. and discovered that the biggest resistance was fear of change.