Make sure that the product that you want to solder, made of steel of this sort, which lends itself to soldering. Very well soldered staples, nails. With great difficulty, if not amenable to this process, the shafts microelectrophoresis.
Take a soldering iron of such power that he was able to warm up the product. Small nails and staples can be soldered to the same device that you used to solder the conventional radio components (25 - 30W). For larger products will have to take the soldering iron capacity from 40 to 200 watts, depending on their size.
Make sure that heating steel parts to a temperature at which soldering will not damage other parts that are with her in thermal contact. For example, steel furniture nail may have a cover plate made of polypropylene, which melts at a temperature of only 165 degrees Celsius. If you remove the items at risk are not available, use as a heat sink pliers and soldering perform quickly.
Tinning steel products carry out using the usual neutral flux (even resin). First, try to zaludit it without Stripping - if the steel is amenable to soldering, this usually happens quickly. The only thing you have to do is get a good warm object. Because it is heavier than, for example, the output of the radio to warm up it will be longer. Of course, you need to hold it not with your fingers, pliers or a similar tool, in order to avoid burn.
If zaludit the surface of the product failed, despite the fact that it is made of steel, amenable to soldering, try to clean the surface and repeat the operation.
Will saludito the same and the second part. Solder tinned the parts together.
Finally, if steel with a conventional soldering flux does not give in, do it. Will saladita it using an active flux. Be extremely careful, since these fluxes contain acid. You can use a pill of aspirin Patriotic (not fizzy). Then immediately saladita detail again, this time using resin or another neutral flux. The durability of such a connection is not guaranteed.
Do not expose the solder joints to mechanical stress. Unlike welded (and even then not all), they are not designed for it.