Switching to metric

A discussion of the 32mm system and its attendant need to convert to metric measure. February 13, 2001

Who is using the "complete hardware solution" (as the guys at True32 refer to it)? I have read the book. It blew my mind that the hardware I have always used all works off the same 32 mm principle and is standardized and predictable no matter what brand you use.

I'm wondering how painful the switch to metric is going to be. I am not sold on the hanging rail with suspension blocks yet, mostly because of the appearance in glass cabinets, and also the fact that my biggest client is an architect that designs all his kitchens with varying heights and levels. I'm afraid the time it would take to hang a rail for each cabinet would outweigh any benefit.

I use leg levelers whenever my cabinetry doesn't have furniture feet, and I use European hinges and drawer slides.

Those of you who use the metric system, how far have you implemented standards in your cabinet construction that coincide with the European hardware you are using? Also, what material do you use for cabinet boxes?

Forum Responses
All of our shop math is set up in metric. All of our customer communications are in inches.

Converting your shop to metric is quite easy. Just change all of the scales on your equipment. It will only take a couple of days for your crew to start getting their arms around millimeters. It might help to issue digital calipers to your crew, available from Reid Tool Supply.

You will have fewer mistakes. Addition and subtraction is less complicated when you don't throw fractions into the equation. Rounding up and down is also less significant, since a half a millimeter is only a 50th of an inch.

When I first started thinking about Euro construction techniques, I read Jon Elvrum's writings.

One of his articles ("Sell in English, Build in Metric," I believe) spoke not of making cabinets, but of making interchangeable parts. Even in our custom cabinets, there are parts that are the same from cabinet to cabinet. The gist of this article was to design your product with as few individual parts as necessary, and as many common parts as possible. The way to achieve this is by using a complete system approach to building your product.

As Bob Buckley points out is his book, "True32," you will not gain the full advantages unless you utilize the entire hardware solution.

In my opinion, the only way to implement this system is with a standard measuring system--millimeters. There are two obvious reasons for this.

1) All the specs are in mm, and contrary to popular belief, 32mm=32mm, not, as we have been lead to believe, 32mm=1 1/4"+ a smidge.

2) All of the equipment is in metric. Why would you want to mess with translations? Why would you want to build a cabinet that has an end panel that is 23 5/8" x 30 5/8", then bore holes that start 46.5 mm from the bottom and end 49.5 mm from the top? It just won't work on a regular basis.

Keep in mind also that your hinges need to be located 94.5 mm from each end of the door. If your system holes are off, the door doesn't match up to the mounting plate.

How painful is the changeover to metric? The math is much faster and easier to do. The biggest hurdle I had was visualizing how big 300 mm was. To overcome this problem, when you see a metric measurement, don't convert in your head--think in mm.

Brian Personett, forum technical advisor

I can't see why suspension blocks or leveling legs should be considered major components of the system. They seem more like frills to me. The engine of the system is the 32 mm grid that leads to so many economies of labor and material.

We use a 19 mm thick nailer cleat on wall and base cabinets and we are working toward converting it into a French cleat to get the same benefit as suspension blocks, without the ugly units inside the case. When our P2P is operating, we will use it to put a notch in the sides of the wall cabinets to allow a continuous wall cleat, sort of like the hanger rail in the suspension block system. I've used this a lot on a non-production basis and it works nicely--it's just that the notching is a hassle without the P2P. We've tried the leveling legs and found them lacking.

We are pretty comfortable with both metric and English simultaneously, though all our casework is metric. We don't think in metric yet, but we are starting to.

Do you plan to run your nailer behind the cabinet back? The hanging strips are intended to be behind the cabinet back. They then don't show. Your side notch would still work. The hanging brackets can be white or chrome and aren't really that ugly, and offer both in/out and up/down adjustment. Installation is a snap. A 35 mm hole can be cut in the cabinet back upper corners with a hinge machine or notched.

I understand what you mean about having the suspension blocks visible in open cabinets or cabinets with glass doors. You could used concealed suspension blocks specially designed and available for this reason. Sources for this hardware are PMI or Häfele. They can answer all your questions regarding leg levelers and suspension systems.