Guards are generally milled using a solid bar stock. This piece is located between the handle and the blade. It is between the ricasso and the handle. The purpose is to literally protect your hand from slipping onto the blade.
Just like anything else knife related, they come in different shapes and styles. Some are purely decorative. That is they line up perfectly with the handle. They can offer some protection. Some guards are intended for balance.
Guards that are intended to protect your hand will often have Quillions. A Quillion is a section of the guard that extends past the handle. This is the area that protects the knife users hand from slipping onto the blade. This extended area is sometimes called a Lug.
You can save yourself some time by using a manufactured piece in your home or professional projects. In addition, using this item adds beauty to that custom knife and therefore it becomes an integral part of the handle.
By machining a piece you can make it to your own dimensions and shape. Most items will polish to a high shine and enhance any handmade knife.
These items are also very durable and functional. At Heimerdinger we carry both brass and nickel silver guards. They come in different shapes, such as oval and elliptical. There are also shaped and unshaped guards. And finally slotted and crowned and lugged. Some guards are ornate or some are beveled.
Of course, filing the shape of the tang will give a secure mechanical fit. Also, for a precise fitting, you have to have the tang thinner than the slot in the guard.
In conclusion, a guard will compliment any hunting, survival, everyday carry, combat or even kitchen knives!