Post Compatibility: Standard 20G (0.81 mm) posts fit standard butterfly backs, screw backs, La Pousette backs, and silicone disc backs. Verify gauge compatibility before purchasing replacement earring backs.
## Push-Back (Butterfly) Closure: Friction-Grip Mechanism
Push-back closures (butterfly backs, friction backs) consist of a stamped metal piece with two spring-loaded wings (scroll shape) that friction-grip the earring post. Dimensions: 5–6 mm width, 4–5 mm height, 0.5 mm metal thickness. Weight: 0.2–0.4 g.
Mechanism: the two metal scrolls apply inward pressure on the post through spring tension. Gripping force: 50–150 g when new. Gripping force decreases with repeated application and removal cycles—typical functional lifespan: 200–500 cycles before tension loss requires replacement.
Earring weight capacity: up to 4–5 g per earring. Earrings exceeding 4 g on push-backs tilt forward (droop) due to insufficient counterweight behind the earlobe. Security rating: moderate—posts can slide out of worn backs during head movement, hair brushing, or clothing changes. Push-backs are unsuitable for high-value earrings or active-wear scenarios.
Materials: sterling silver push-backs for silver earrings, 14K gold push-backs for gold earrings, surgical stainless steel push-backs for steel and titanium earrings.
## Screw-Back Closure: Threaded Post Mechanism
Screw-back closures consist of a threaded earring post and a matching threaded disc or cup that screws onto the post. Thread specification: approximately 0.5 mm pitch, 20G post diameter. Screw-back disc dimensions: 5–8 mm diameter, 3–4 mm height. Weight: 0.3–0.6 g.
Mechanism: clockwise rotation engages the thread, drawing the back tight against the earlobe. Full engagement requires 5–8 rotations. Application time: 5–15 seconds per earring. Removal: counter-clockwise rotation. Screw-backs cannot slide off accidentally—only intentional rotational force disengages the closure.
Earring weight capacity: up to 8 g per earring (thread engagement provides superior retention versus friction). Security rating: high—accidental loss requires both thread failure and back separation, which is statistically rare. Screw-backs are the standard closure for diamond stud earrings, gemstone stud earrings, and precious metal studs in retail fine jewellery.
Disadvantages: application difficulty for wearers with reduced finger dexterity (arthritis, neuropathy). Thread wear over 1,000+ cycles reduces engagement reliability. Cross-threading risk during hurried application damages thread profile.
## Lever-Back Closure: Hinged Wire Mechanism
Lever-back closures integrate a curved wire (0.7–0.8 mm gauge) that passes through the piercing with a hinged lever arm that snaps into a catch behind the ear. Wire length: 15–20 mm (piercing to hinge point). Lever arm length: 8–12 mm. Total closure dimensions: 18–25 mm height, 8–12 mm width. Weight: 0.4–0.8 g.
Mechanism: the curved wire inserts through the piercing. The lever arm swings upward (open position) or downward (closed position) on a pin hinge. A detent or spring catch holds the lever in the closed position. Closing produces an audible click confirming engagement.
Earring weight capacity: up to 15 g per earring. The curved wire distributes suspended weight across the full earlobe thickness rather than concentrating load on a single post point. Security rating: high—the closed lever blocks the wire from backing out of the piercing.
Lever-backs are the standard closure for drop earrings, dangle earrings, and chandelier earrings. Lever-back quality varies: die-cast lever-backs (budget) exhibit faster spring fatigue than machined lever-backs (premium). Hinge pin material affects longevity—stainless steel pins outlast brass pins.
Upgrade Option: Replace standard push-backs with La Pousette backs on diamond studs, gemstone studs, and any earring valued above AUD 200. The closure upgrade costs AUD 15–40 and provides the security of screw-backs with easier operation.
## La Pousette (Guardian) Closure: Spring-Loaded Grip Mechanism
La Pousette closures (also marketed as guardian backs, monster backs, secure backs) feature a spring-loaded mechanism with two squeeze tabs. Dimensions: 8–10 mm width, 6–8 mm height. Weight: 0.5–1.0 g.
Mechanism: pushing the La Pousette back onto the post engages internal spring jaws that grip the post. Gripping force: 200–400 g (4–8 times stronger than push-back friction). Removal requires simultaneous squeezing of both lateral tabs to release the spring jaws. One-hand application (push on); two-hand removal (squeeze tabs).
Earring weight capacity: up to 10 g per earring. The disc-shaped body provides surface area contact with the earlobe, acting as a stabilisation plate that prevents forward tilt of heavy studs. Security rating: very high—accidental release requires simultaneous bilateral pressure on both tabs, which does not occur during normal wear.
La Pousette backs are available as aftermarket replacements (AUD 15–40 per pair in sterling silver or 14K gold). Universal-fit La Pousette backs accommodate 0.7–0.9 mm post diameters.
## Locking and Proprietary Closure Mechanisms
Proprietary locking backs use brand-specific mechanisms: magnetic locks (neodymium magnet pairs, 100–300 g attraction force), cam-lock mechanisms (quarter-turn engagement), and patented spring-lock designs. Dimensions vary by manufacturer: 8–14 mm diameter. Weight: 0.5–1.5 g.
Magnetic closures offer accessibility for wearers with dexterity limitations—no fine motor manipulation required. Magnetic closure strength is fixed and non-adjustable. Magnetic backs are incompatible with MRI environments (magnetic resonance imaging) and must be removed before medical imaging.
Security rating: varies by mechanism—magnetic: moderate to high; cam-lock: high; patented spring-lock: very high. Replacement availability: proprietary backs are sourced only from the original manufacturer, limiting replacement options.
## Disc Back (Comfort Back) Closure: Weight Distribution Platform
Disc backs are circular platforms (8–12 mm diameter, 1–2 mm thickness) in plastic (acetal, polyethylene) or metal-rimmed silicone that slide onto posts behind push-back or screw-back closures. Weight: 0.3–0.5 g.
Function: disc backs distribute earring weight across 50–110 mm² of earlobe surface (versus 15–25 mm² for push-backs alone). Weight distribution prevents forward tilt of heavy stud earrings and reduces point-pressure discomfort during extended wear. Silicone disc backs additionally provide a soft contact surface and hypoallergenic barrier between metal back and skin.
Disc backs are supplementary closures—used in addition to a primary back (push-back or screw-back), not as standalone closures. They are standard accessories for stud earrings exceeding 3 g.
## Earring Back Selection by Earring Type and Value
Stud earrings under AUD 100, under 3 g: push-back closure. Stud earrings over AUD 100 or over 3 g: screw-back or La Pousette closure. Drop earrings under 8 g: hook with silicone stopper or lever-back closure. Drop earrings over 8 g: lever-back closure (mandatory for weight distribution). Hoop and huggie earrings: integrated hinged snap closure. Ear cuffs: spring-tension self-closure (no back required). Clip-on earrings: integrated spring-hinge or screw-tension mechanism.
Aftermarket back replacement is available at most Australian jewellers. Standard push-back replacement: AUD 5–15 per pair. La Pousette upgrade: AUD 15–40 per pair. Screw-back conversion (requires post replacement): AUD 30–80 per pair. Back replacement does not alter the earring's decorative front or gemstone setting.