Post and Back — The Standard Pierced-Earring Finding
Post and Back — The Standard Pierced-Earring Finding
The straight-post stud with friction back, in gold, platinum, and silver
The post and back is the standard pierced-earring finding consisting of a straight cylindrical metal post that passes through the earlobe and is secured on the back side by a removable friction-fit retainer (the back, also called the butterfly, scroll, or nut). The combination is the dominant earring closure in contemporary jewellery for stud earrings, small drops, and any earring that does not use an alternative closure such as a lever back, fish hook, or kidney wire.
Components and construction
The post itself is typically a 0.7 to 0.9 millimetre diameter cylinder, soldered or laser-welded to the back of the earring component, and finished with a smooth or threaded tip depending on the back style intended. Smooth posts are matched with friction-fit butterfly backs that grip the post through a split metal collar; threaded posts are matched with screw-on backs that thread onto the post for additional retention security. The post length is conventionally 9 to 11 millimetres, with shorter posts available for thinner earlobes and longer posts for thicker piercings.
The back is the small retainer that holds the post in place. The standard friction back is a stamped or cast butterfly form with a central collar and two folded wings that allow the user to grip and adjust the back's position on the post. The collar is dimensioned slightly smaller than the post diameter and grips through elastic deformation when the back is slid on; well-made backs grip firmly while still allowing repeated removal and replacement.
Materials for both post and back match the earring's metal: 14 karat or 18 karat gold for gold earrings, platinum for platinum, sterling silver for silver, and titanium or surgical steel for hypoallergenic and value-tier production. Mixing materials between the post and back is occasionally encountered in budget production but is not recommended for fine work.
Variants and security alternatives
Several variants of the basic post-and-back design address security and comfort. The large-back friction back uses an oversized retainer (sometimes called a jumbo back) that distributes load more broadly across the back of the earlobe and reduces the risk of the earring tilting forward under its own weight. The screw-on back uses a threaded post and matching threaded back, with positive retention from the screw threads rather than friction; it is the standard for high-value diamond and pearl studs where loss prevention is critical.
The locking back uses a spring-loaded mechanism that engages a notch on the post for active retention, requiring deliberate release for removal. Locking backs are common in high-value work and in earrings worn by active users (athletes, performers) where friction backs would not provide sufficient retention.
Comfort and ear-health considerations
The post diameter and finish affect comfort during long wear and can affect skin response in users with metal sensitivities. Polished, burred-edge-free posts in nickel-free alloys are appropriate for sensitive ear piercings; nickel-bearing alloys are subject to regulation in many jurisdictions and are best avoided for posts intended for prolonged contact. Healed-piercing standards in many jurisdictions require post diameter and material to meet defined specifications.
In the trade
The post-and-back is the default earring finding for most contemporary production and is supplied by major findings manufacturers in standard sizes and metals. For dealers and customers, the principal evaluation points are post diameter and length matched to the user's piercing, the security of the back type matched to the earring's value and use case, and the metal compatibility between post, back, and earring component. Replacement backs in standard sizes are widely available; mismatched or worn backs should be replaced to maintain retention security on valuable pieces.