BAG-24, 50% Silver, is Cadmium free and is a compromise. The strongest non-Cadmium alloy is BAG- 22, 49% silver with manganese, but it is a bit gummy in the flow. Commonly used is BAG-7, 56% silver with Tin, because it wets out readily however it is a very weak brazing alloy and joint failure is common with this alloy.

This is an excellent product but does have Cadmium. The classic is BAG-3, 50% silver with Cadmium. There are several brazing alloys used for carbide. For small parts we use a can of spray oven cleaner from the supermarket. The cheapest and most effective was a barbecue and oven cleaner from the local janitorial supply. There is a wide variety of cleaners that work with varying degrees of success. The best steel cleaner seems to be a strong caustic substance. A high, round shape means trouble brazing.

The wider and flatter the puddle, the better. Put a drop of water on the surface and see what shape it forms. The easiest way to test steel cleanliness is with an eye dropper or similar. Most of the really effective solvents are now illegal so it is now common to use legal solvents that don’t work very well. It used to be common to use vapor degreasing and very aggressive solvents to clean steal. You can see that the alloy flowed well over the steel and not at all on the carbide. We put a small bit of brazing alloy dipped in Black flux in the middle of one steel part (left) and two carbide parts (right) and heated them with a torch. He thought it was the chrome in the steel. The manufacturer couldn’t get the carbide to stick to the steel. Test carbide parts for wetting or Brazeability. There are also companies that will treat the carbide and pretin it with brazing alloy so that it is ready to use when you get it. The simplest is just to specify that the carbide be wettable when you order it. You can clean carbide by grinding the surface with a sander or a bench grinder. Tungsten carbide with any sort of oil, grease, oxide or free carbon on it will not braze. The carbide must be wettable, it must want to chemically and physically bond with the brazing alloy. There are many additional articles on How to Braze in our Brazing index. Brazing tungsten carbide is a very easy and reliable process if a few simple steps are taken but the steps are not necessarily obvious or widely known. I routinely get calls from people who are having trouble brazing carbide and don’t know why. Basic Carbide Saw Tip Information and How To Order.Grinding Carbide- Health and safety risks.

How to grind carbide