Cuff bracelets are my most favorite piece to wear and to design. They are such a statement jewelry piece, and the ones I have designed lately have been some of my best work.
In designing a cuff bracelet, I typically start with 6 inches of metal, usually copper or sterling silver. After hammering and forming the cuff, the cuff size is approximately 7 1/4 inches, including the gap opening in the back. In this specific instance, the cuff would fit a wrist size 6 to 7 1/4 inches; of course I could always design a cuff with a customer's exact wrist measurements in mind. My own wrist size is actually 5 1/2 inches, and I am still able to wear my cuff designs without any problem. When I wear a cuff bracelet they are always loose, as my wrists are very small. Fit is important, but the most important detail when wearing a cuff bracelet is that the gap opening is small enough; therefore, the cuff is not able to fall off.
After a cuff bracelet is formed, it is NOT really meant to be adjusted. The metal becomes very hard, and any warping of this hard metal could bring about some unwanted results - any pushing or pulling of the hardened metal could cause your gemstone(s) to loosen or even fall out. Then there comes the screaming and shouting ... let's avoid this situation all together, shall we.
The gap opening located on the back of your cuff bracelet is large enough to accommodate almost any wrist size. There will be no need to open the gap to fit the cuff onto your wrist. You do not want your gap any larger, as the tight gap keeps your cuff in place on your wrist and not on the floor. You don't want your favorite new cuff to fall off because you stretched the gap opening, do you?
Follow the step by step in the attached video to see how this cuff can fit almost any size wrist, without any adjusting or distorting of your cuff: