Properly handled, the attractive beaded appearance of half- and full-bead wire offers a beautiful decorative touch ideal for frames and accent work. The key to using bead wire is understanding its strengths and weaknesses. Because bead wire is very slender between the beads, it is best used as a decorative element and always with an underlying supportive substrate such as sheet stock or another wire. Here is why:
Most of us have bent a piece of wire back and forth in one place until the wire breaks—even hard wire like a paper clip will yield after just a few repetitions. This kind of a break is called a "fatigue failure" and it occurs because every time the wire is bent, the metal work hardens a little in the bend zone. Each bend forward or back adds a little more hardness until the structure of the metal is no longer malleable and it breaks. The more localized the bend is, the faster the metal work hardens so, as shown below, if the wire is clamped in a vise and bent acutely against the vise jaw, the work hardening will be very localized and the hardening will overcome the metals malleability very quickly.
If the same wire is held in your two hands and bent, the bend will have a much larger radius, so the work-hardening will be spread over much more material and the material will withstand more bends before fatigue failure occurs.
On the full-bead wire shown here, the bead diameter measures approximately .080” (2mm); the wire diameter between beads (called the neck) is about .040" (1mm). The narrow area is the weakest point of any bead wire. When the wire is bent, it will bend at the at the narrow area(s). Due to the design of bead wire, the narrow areas make up only about 4% of the overall length of the wire—the beads make up the majority of the length, approximately 96%. (Exact figures will depend on the bead diameter of the specific wire; the figures here were measured using an optical comparator that uses light to precisely measure very fine areas.)
The bead wire shown here is bent by hand to a 90° angle. You can see that the wire bent between the beads at the narrow areas and that the bend radius spread to two of these areas. When the bend brings two beads together, they begin to act as a lever, putting further stress on the narrow area between them. Notice the gaps between the beads in the bend zone of our sample wire; they narrowed on the inside of the bend and expanded on the outside, while the bead itself is virtually unchanged. The metal in the narrow areas on the interior of the bend is under a lot of compression pressure, and the metal in those areas on the exterior is under a lot of tension pressure (arrows A and B).
This view is looking straight at the outside of the bend while the wire is still bent. The A and B arrows on this photo correspond to the arrows in the previous photo. While the wire is still in one piece, the narrow areas of the bend have already started to tear. Straightening the wire (bending it back in the opposite direction) will cause fatigue failure and the wire will break just as demonstrated with the round copper wire in the vise test (where the wire broke after one back and forth bend cycle) because the work is concentrated in a very small length of wire.
Half-bead wire is weaker than full-bead wire because the bend angle is less limited on the flat side and there is only half as much material between beads. For example, in the illustration at left, you can see that a ring made from half-bead wire will not be truly round on the inside; it is a polygon. In use, a ring is flexing all the time. How many times have we seen rings that were bent out of shape simply by being worn? Every time the hand moves to grasp, press, push or pull, there is pressure on the ring, and it flexes. If the ring is made from bead wire or half bead wire, the flexing is highly concentrated in the narrow areas between the beads; they fatigue and break very quickly.
The cardinal rules, when it comes to forming bead wire into curves or shapes, are:
|Full-Bead Wire Diameter||Minimum Circle Diameter|
To take advantage of full- or half-bead wire, solder the wire to a piece or an area of supporting material: a length of flat wire, a strip of sheet (the same width or a little wider than the wire), or a larger design piece. For a ring, the assembled overlay supports the bead wire during the bending to form a ring. If desired, oxidize the piece to highlight the beading, polishing the beads and leaving the background dark. The finished ring (or other design) will be strong, quality piece of jewelry that customers can wear and enjoy for many years to come.
To form a circle component with bead wire, whether half- or full-bead, choose a wire size that will allow you to make the circle size you want without allowing the beads to contact one another.
In this side view, a length of half-bead wire is overlaid on a strip of sheet to add strength for forming a ring.
In this top view, after soldering and oxidizing, the beading is bright against the dark background.
Bead wire, both half- and full-bead, offers a great way to add depth and detail to your jewelry designs. Used properly, this wire is simple to apply and adds an intricate and professional look to a wide variety of jewelry styles. See Rio's selection of full- and half-bead wire in sterling, gold, high-karat gold, gold-filled and bronze.