Various emails have made clear that we live in different worlds! I have dealt with hard tooling so long that I forgot that someone who isn't involved in manufacturing would not have been exposed to things like injection molds. So, here is a not-too-brief explanation of some things that are impacted if a manufacturer must make certain types of changes to comply with metric mandates. First, a couple of definitions: "tooling" is how manufacturers refer to custom items that help produce a product, but are not part of the product itself. Examples include injection molds (for making plastic parts), die-cast molds (for making metal parts), work-holding jigs or alignment jigs, steel-rule dies, etc. The cost of the tooling must be amortized into the cost (and thus price) of the product. The tooling is usually useless for making anything except the part for which it was designed to make. "volume" is how manufacturers refer to the number of items produced. A "low volume" product might be one to a few thousand (a specialized lab instrument). A "high volume" item might mean hundreds of thousands to millions (a disposable syringe). In some cases, where materials (paper, leather, plastic, metals) are machined on programmable equipment (mill, lathe, water knife, laser cutter), making changes to the product costs money and time in engineering, but there would be no significant tooling costs involved. These types of equipment are used where the volume is low, or rapid changeover is required. However, in some cases there are tooling costs required. At the low-cost end, this might just be a work-holding fixture, an alignment jig, or a simple steel-rule die, ranging from a few hundred to a few thousand dollars. Such tools are used in small to medium volume applications. Where the volume is high (syringes, a common screw) or the a part is complex (most molded plastic parts), a manufacturer will pay to produce "hard tooling" which produces exactly that part. For example, a plastic injection mold to produce the case for a handheld calculator. If the manufacture needs 2,000 cases a year, he will make an aluminum mold, which will cost about $25,000 and will be good for 10,000 parts ($2.50 amortization per part). If it is a syringe which he wants to make a million of each year, he will make a hardened steel, chrome-plated, multi-cavity mold which will cost $300,000 but will run for hundreds of thousands of cycles and produce 40 syringes per cycle (a few pennies amortization per part). Other examples include: progressive die sets (to stamp identical parts out of roll material in several stages) at $30k to $250k each; permanent steel dies, for cutting or shaping large volumes of sheet material ($10k to $100k). In most cases, some aspect of the hard tooling is designed around dimensional requirements, whether they be colloquial or metric. For example, a progressive die may make connector pins on 0.1" centers. Converting this to (say) 2 mm centers would mean throwing out the die and making a new one. An injection mold may have alignment holes to accommodate a #4 screw, or may have a "slide" that produces a thread for a #10-24 bolt. It may be possible to substitute a different fastener, or the mold might have to be modified (possible sometimes, but expensive), or, in some cases, discarded. Likewise, a mold for blow-molding detergent bottles will produce a certain volume bottle, say 64 ounces. Of course the label can be changed to metric, but to change the size of the bottle to hard metric would probably mean throwing away the mold and making a new one. Anytime you say "metric-only laws" to a manufacturer, they will immediately worry about having to replace thousands or millions of dollars of hard tooling. So, if a person's desire is a soft conversion (labels only), that needs to made very clear when talking to manufacturers. Finally, any manufacturer has quality control instruments such as calipers, gauges, precision weights and blocks, etc. There are millions of these around the country which are colloquial-only. Of a manufacturer has to replace these with metric instruments, in order to properly monitor metric products, that would be another huge expense. Now, about one specific injection mold my company makes, excuse the colloquial measurements, but that is how the industry operates. Cost: about $45,000 Time: six months to produce the mold Product molded: a "clamshell" case (front and back) Mass: about 3200 pounds Press: runs on a 400-ton press that is about the size of a school bus. The "400-ton" refers to the force with which the two halves of the injection mold are pressed together as the plastic is being injected at about 10,000 psi. Other: It has two main halves, a set of ejection pins to push the parts out, cooling channels for water to cool the plastic, hot runners so the plastic stays melted in the feed "tubes", and a hydraulic slide to create a cutout in the side of one part. In other words, an expensive, complex piece of equipment. You can see the case it produces at http://www.qsicorp.com/images/type-w_large.jpg. I don't have a picture of the mold itself, but will take one next time I am at the molding vendor. Inside the case are numerous bosses, recesses, some molded in metal pieces, etc. Hope this clarifies a few things. Jim Elwell
