An eyebrow barbell is a type of jewelery often used in eyebrow piercings. This particular piece of jewelery gets its name from its resemblance to the barbells used in weightlifting. Eyebrow piercings can hold either a curved or straight eyebrow barbell, both of which can be either internally or externally threaded. While the classic eyebrow barbell is a plain metal rod with a round metal ball at each end, artistic variations on the simple design are widely available.
Eyebrow barbells come in a variety of sizes to guarantee an accurate fit for many different face sizes and shapes, and few key measurements help determine which eyebrow barbell will fit an individual the best. The length of a straight barbell is determined by measuring the shaft in between the two balls or other end pieces. The direct distance between the two end pieces is measured from the inside of the curve to determine the length of a curved barbell.
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The thickness of the shaft is referred to as the gauge, with lower gauge numbers indicating thicker shafts than higher gauge numbers. An 18 gauge eyebrow barbell is thinner than a 12 gauge eyebrow barbell. The 18 gauge is the thinnest shaft available and measures 0.04 inches (1.0 millimeters) in diameter.
The final measurement for an eyebrow barbell is the ball size or size of the end pieces. Traditional barbells have a ball on each end of the shaft, and they are simply measured from top to bottom. Conical end pieces, which are fairly common, are measured across the base, which is the widest part. Custom shapes vary in their measurements, as there are so many possibilities for unique end pieces.
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Another distinguishing feature of the eyebrow barbell is the threading used to attach the end pieces to the barbell shaft. In order for the barbell to be pierced through the skin of the eyebrow area, at least one of its ends must be detachable. To accommodate this, either the balls or shaft are threaded so that the ends can simply screw on and off.
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External threads are visible on the end of the shaft when the ball is removed. To refasten, the corresponding hole in each ball is placed over the shaft, and the ball is twisted to tighten. One potential problem with external threading is that the threads can get caught inside the piercing during removal if appropriate care is not taken.
The alternative, internal threading, works much the same way but is reversed. Each ball has a small protruding screw, instead of a hole, which is placed inside a hollow shaft and screwed into place. Internal threading ensures that the shaft itself is smooth and less likely to snag while the jewelery is being inserted.