Externally Threaded Curved Barbells: Steel Banana Bars for Eyebrow, Navel & More
Externally threaded curved barbells in 316L implant-grade steel give you a reliable, budget-friendly option for fully healed eyebrow, navel, daith, and rook piercings. This collection covers 14G through 18G in plain high-polish steel and black PVD, with multiple lengths and ball sizes to match your exact anatomy. Every externally threaded curved barbell here threads clean and wears flat.
What Is an Externally Threaded Curved Barbell?
An externally threaded curved barbell is a gently arced steel bar with a removable ball end on each side. The curve follows the natural contour of anatomical placements like the eyebrow ridge and navel, which is why a curved barbell puts less pressure on the entry and exit points of the piercing than a straight bar would. The externally threaded design places the screw threads on the outer surface of the pin that extends from each ball end. Those threaded pins screw into the open tips of the bar, locking the balls in place.
Curved Barbell vs. Banana Bar: Same Thing?
Yes. Curved barbell and banana bar refer to the same piece of jewelry. "Banana bar" is the colloquial term used most often for navel piercings, where the curved shape resembles a banana. In professional and studio contexts, the piece is called a curved barbell. In product listings and search results, both terms appear interchangeably. If you have been searching for banana bars and landed here, you are in the right place.
Externally Threaded vs. Internally Threaded Curved Barbells
The threading system determines how the ball ends attach to the bar and how much exposed hardware contacts the piercing channel during jewelry changes.
Externally Threaded:
- Screw threads sit on the outside of the ball end pin
- Threaded surface contacts the piercing channel during insertion and removal
- Appropriate for fully healed piercings where the bar is not changed frequently
- More affordable manufacturing cost reflected in lower price
- Compatible with externally threaded ball ends and replacements only
Internally Threaded:
- Threading is recessed inside the ball end, bar surface stays completely smooth
- No exposed thread ridges contact tissue during jewelry changes
- APP-recommended for both initial and healed piercings
- Preferred by professional piercers, particularly for surface and eyebrow placements
- Compatible with internally threaded ends only
Externally threaded curved barbells are a practical, cost-effective choice for stable, fully healed piercings. If your piercing is healed and you change jewelry infrequently, the externally threaded system functions reliably without the additional cost of internally threaded jewelry.
Externally Threaded Curved Barbell Styles in This Collection
Every externally threaded curved barbell in this collection is machined from 316L implant-grade stainless steel. Variation across the lineup comes from surface finish and end style rather than material quality.
Plain High-Polish Steel
Mirror-polished steel curved barbells are the most straightforward replacement option and the most versatile finish in the collection. The high-polish surface pairs with any aesthetic, holds up well to daily wear, and is easy to clean. Plain steel externally threaded curved barbells in 14G and 16G cover the majority of healed navel and eyebrow placements and are the default starting point for anyone replacing a worn or tarnished piece.
Black PVD Coated Curved Barbells
Physical vapor deposition coating bonds a black finish to the 316L steel surface at a molecular level, creating a significantly more durable result than standard plating. Black PVD externally threaded curved barbells are available across 14G, 16G, and 18G in this collection. The black finish is a consistently popular choice for eyebrow piercings where a darker tone creates a cleaner contrast against the skin and pairs well with other facial jewelry in similar finishes.
Gem-End and Decorative Curved Barbells
Some externally threaded curved barbells in this collection feature gem-set bottom ends, PVD-finished top balls, or decorative shaped ends in place of standard plain balls. These styles are most popular for navel piercings where the bottom end is the primary visible decorative element. Gem-end options in clear CZ and colored stones appear in this collection for shoppers who want more visual impact without switching to a different jewelry style entirely.
See more: Steel Externally Threaded Ends
Sizing Guide: Gauge, Length, and Ball Size by Piercing
Gauge and length are the two variables that determine whether an externally threaded curved barbell fits correctly. Getting both right means the jewelry sits flush, moves minimally, and does not embed into or pull at the tissue on either side.
Eyebrow:
- Gauge: 16G (standard for most eyebrow piercings)
- Length: 3/8 inch (10mm) for healed piercings; 7/16 inch (11mm) for initial
- Ball size: 3mm to 4mm; smaller balls sit more discreetly against the brow
Navel:
- Gauge: 14G (industry standard for navel piercings)
- Length: 3/8 inch (10mm) to 7/16 inch (11mm) for healed; 1/2 inch (12mm) for initial
- Ball size: 4mm to 5mm on top, 5mm to 8mm on the decorative bottom end
Daith:
- Gauge: 16G
- Length: 5/16 inch (8mm) to 3/8 inch (10mm) depending on ear anatomy
- Ball size: 3mm to 4mm
Rook:
- Gauge: 16G
- Length: 5/16 inch (8mm) to 3/8 inch (10mm)
- Ball size: 3mm for a low-profile fit in the cartilage fold
Vertical Labret:
- Gauge: 16G or 14G depending on original piercing
- Length: 3/8 inch (10mm) to 7/16 inch (11mm)
- Ball size: 4mm to 5mm; match top and bottom for a symmetrical look
Always purchase the length that matches your current confirmed healed size. Wearing initial-length jewelry on a fully healed piercing means excess bar length that catches on clothing and slows the surrounding tissue from settling.
Initial Jewelry Length vs. Downsized Length
When a curved barbell piercing is fresh, the piercer fits a longer bar to accommodate swelling, typically 1/2 inch (12mm) or longer for navel, and 7/16 inch (11mm) for eyebrow. Once swelling resolves, usually six to twelve weeks post-piercing, downsizing to a shorter bar reduces movement and snagging. Most healed eyebrow piercings settle at 3/8 inch (10mm). Most healed navel piercings settle at 3/8 to 7/16 inch (10 to 11mm). If you are still wearing your initial jewelry and it moves visibly or catches on fabric, downsizing is overdue.
How to Measure Your Current Barbell
Remove one ball end from your current curved barbell and measure the bar from tip to tip, not including the threaded tips. That straight-line measurement is your wearable length. Standard options in this collection are 5/16 inch, 3/8 inch, 7/16 inch, and 1/2 inch. Round to the nearest standard size if your measurement falls between two options.
See more: Steel Externally Threaded Barbells
Best Curved Barbell Picks by Piercing Type
Matching gauge, length, finish, and ball size to the specific placement produces a more comfortable, better-looking result than selecting by price or style alone.
Eyebrow Piercings (16G)
Eyebrow piercings are surface-level placements that sit just under the skin along the supraorbital ridge. A curved barbell follows the natural contour of the brow better than a straight bar, reducing pressure on the entry and exit points and lowering the risk of migration over time. For healed eyebrow piercings, a 16G plain steel externally threaded curved barbell at 3/8 inch with 3mm ball ends is the standard reliable setup. Black PVD versions at the same dimensions are equally popular for wearers who prefer a darker finish that frames the brow without reflecting ambient light.
Navel Piercings (14G)
The navel is the most common placement for a curved barbell because the anatomy of the belly button opening naturally suits the banana shape. A 14G externally threaded curved barbell at 3/8 to 7/16 inch fits the majority of healed navel piercings. The top ball sits inside the navel and should be small enough not to press against the surrounding skin; 4mm to 5mm covers most anatomies. The bottom ball is the visible decorative element and can be a plain steel ball, a gem-set end, or a larger decorative piece depending on the look you want.
Daith and Rook Piercings (16G)
Daith and rook are inner-ear cartilage placements where the curved shape of the barbell follows the contours of the helix and antihelix respectively. A 16G externally threaded curved barbell at 5/16 to 3/8 inch with 3mm ball ends fits most healed daith and rook placements. Plain steel and black PVD are both well-suited to these inner-ear positions where the jewelry sits within the ear bowl and benefits from a low-profile, non-snagging design.
Vertical Labret Piercings (16G/14G)
A vertical labret uses a curved barbell that enters through the lower lip and exits just below the lip line, with both ball ends visible. The curve follows the natural protrusion of the lip rather than passing through the inside of the mouth. A 16G or 14G externally threaded curved barbell at 3/8 to 7/16 inch with matching 4mm to 5mm ball ends on both sides covers most healed vertical labret anatomies. Because this placement moves constantly during speaking and eating, confirming the barbell length fits flush before purchasing is more important here than in any other placement.
Why Choose 316L Steel for Curved Barbells?
The material of a curved barbell determines long-term comfort, skin response, and how the surface holds up over months of daily wear. For a piece that stays in the body continuously, material choice matters beyond aesthetics.
316L Implant-Grade Steel vs. Fashion Steel
Fashion-grade stainless steel body jewelry, common on general marketplace platforms, may contain elevated nickel content that migrates into surrounding tissue over time. For a placement like the eyebrow or belly button that sits against skin permanently, prolonged nickel contact is a documented source of persistent irritation and allergic contact dermatitis. Implant-grade 316L stainless steel is formulated to minimize nickel ion release and is the material specification that professional piercing studios use for healed jewelry. Every externally threaded curved barbell in this collection is manufactured to that standard.
PVD Coating Durability
PVD coating bonds the finish to the 316L steel surface through a molecular-level vacuum process rather than sitting on top as a plated layer. This means PVD-coated externally threaded curved barbells resist chipping, peeling, and fading significantly better than electroplated alternatives. With mild soap cleaning and normal daily wear, a quality PVD finish on a steel curved barbell maintains its appearance for years.
When to Consider Internally Threaded Instead
If you are setting up a new piercing or have experienced persistent irritation on a healed placement, the smooth post surface of an internally threaded barbell removes the externally threaded friction point entirely. The
Steel Internally Threaded Curved Barbells collection covers the same gauge range and placement types with APP-recommended threading for both healing and healed stages.
Why Shop Externally Threaded Curved Barbells at Pierced Addiction?
Pierced Addiction sources externally threaded curved barbells through Metal Mafia, a supplier with over two decades of experience serving professional piercing studios across the United States. Every piece in this collection is machined from 316L implant-grade steel to consistent thread tolerances, ensuring clean ball end changes without cross-threading or galling on a properly matched gauge.
The gauge and length range here covers the realistic replacement and downsize needs of the most common curved barbell placements, from standard 14G navel lengths through 16G and 18G eyebrow and cartilage sizes. Free domestic shipping on all orders over $25, same-day processing on domestic orders placed before 1pm, and responsive customer support make Pierced Addiction a reliable first stop for healed piercing jewelry in implant-grade steel.
Frequently Asked Questions
Find quick answers to the most common questions about externally threaded curved barbells, sizing, compatibility, and care.
Are externally threaded curved barbells safe for healed eyebrow piercings?
Yes. On a fully healed eyebrow piercing where the bar is not being changed frequently, externally threaded curved barbells function reliably and are appropriate for long-term daily wear.
What length curved barbell do I need after downsizing?
Most healed eyebrow piercings settle at 3/8 inch (10mm). Most healed navel piercings use 3/8 to 7/16 inch (10 to 11mm). Measure your current bar from tip to tip without the ball ends to confirm your size.
Can I swap the ball ends on externally threaded curved barbells?
Yes. Ball ends unscrew counterclockwise. Replacement ends must be externally threaded and match the gauge of the bar exactly. A 14G end will not thread correctly onto a 16G bar.
What gauge is standard for navel vs. eyebrow piercings?
Navel piercings are typically 14G. Eyebrow piercings are typically 16G. Match your replacement to whichever gauge your piercer used for your initial jewelry.
Is a curved barbell the same as a banana bar?
Yes. Curved barbell and banana bar describe the same jewelry style. Banana bar is the colloquial term used most often for navel piercings; curved barbell is the broader professional term that applies to all placements.
Externally threaded curved barbells in 316L implant-grade steel cover the most common healed placement needs at a price point that makes restocking or trying a new finish easy. Shop the full selection above to find your gauge, length, and finish.