Forging hollow metal handle on a knife is much easier than you might think. Step by step instructions are provided here
To begin, you will need to use an anvil and hammer to shape the blank into the desired shape. The blank should be flat and clean with just a few dents or marks. It is important to note that the blank should not be too thick or thin as you want it to fit snugly in the handle of your knife
Next, you will want to sand down any rough edges and rough spots on your blank so that it can be polished smooth. This process may take some time but will save you from having to use sandpaper later on in the process if something doesn't go right. Afterwards, apply some lubricant on both sides of your blank and then press them together with a mallet until they fit snugly together. If necessary, add more lubricant on top of this one so that it does not stick together too much when pressing down hard on it with a mallet again. You can even add some type of glue at this point if needed for strengthening purposes depending on what type of material you are using for forging hollow metal handles on knives.
how to forge hollow metal knife handle