TECH TIPS, Specials, and Racing News for September, 2009!

Punch and Flare Tips

There are not a lot of places when working with sheet metal where you can reduce weight in the panel and add strength at the same time. The most common way to achieve this is to

hole punch and flare the panel. You can see this used on many race cars, custom cars, and aircraft. There are 2 ways to do this: one way is to use a punch and flare tool which cuts and flares all in one application (this tool also can double as a punch only tool). The other method is to use a standard hole punch which you may already have and then use a Mittler Bros. flare tool. The Punch and Flare tool will save time by doing both operations at once. Some of the features I like on the Mittler Bros. tool may seem insignificant but I find are very nice features. The first feature is a simple bearing on the tightening bolt. When torquing down on the bolt during the punching process, this bearing eliminates binding and galling of the metal to make the process much easier.

The second item that is very important are the tolerances of the cutter dies. Mittler Bros. manufacturers both dies for automotive and aircraft use with different tolerances for the metal thicknesses for the metal used in each application. You may think "so what" but I own another manufactures sets of punch and flare tools and the problem I have is that they work well on heavier gage metal but when used on stock car sheet metal [24 ga.] or thin aluminum, the tolerances are so loose that the panel distorts making for a poor quality job. Mittler Bros. can answer your questions on which one is right for your application.

The next option to do a very nice flare if you already have a punch set is as I said above is the Mittler Bros. flare tool. Once the hole is punched to the proper size, the flare tool does a very nice professional looking job on your panel. Another feature with this tool is that it has a small ridge which centers the tool perfectly for a nice flare. I have been using this set up for years and have had nothing but excellent results. Now here is is some advice so you do not do what I did, check your punch set and make sure it is a true size set which means a 1" punch is a true 1" punch. If the set says conduit or pipe, your holes will be too big and your flares will turn out terrible. Conduit and pipe is measured I.D, it is not an issue just cutting hole but it is when using it in conjunction with a flare tool. It was a costly error for me.

Now the last tool Mittler Bros. has that does a similar job is their Punch and Bead tool.

Similar to the Punch and Flare tool discussed above, this tool rather than flaring the metal makes a bead with a small lip. I really like this tool when having to run hoses or wire bundles through a fire wall because with the small lip, I can install a grommet to protect the wires/hoses and the bead add strength to the metal panel. For you custom car/bike builders, these dies can be used to create some very cool effects on your metal panels with fairly minimal effort.

Lastly, if you are looking for production both the Punch & Flare and the Punch & Bead tools can be used with Mittler Bros. Bench Press. They have an adapter with a spring loaded center pin that really increases production. These Bench Presses come in both manual and hydraulic applications. Mittler Bros also has several other tools that can be used on this machine adding to its versatility which we will be discussing this in future installments.