What is Zipper?

A zipper (also called a zip or slide fastener) is a fastener that opens and closes when a slider interlocks and separates the facing teeth on two tapes. The Turkish Language Association (TDK) defines fermuar as a “device used on garments, bags and the like, made up of facing teeth and a closer that runs over them” (our translation from the Turkish) and notes that the word comes from French fermoir. In garments, a zipper is defined by its tooth type, end construction and size number.

Parts of a zipper

• Tape: The band the teeth are attached to; generally polyester (YKK, 2022).
• Teeth and chain: The interlocked teeth together are called the chain.
• Slider and puller: The slider is the moving part that interlocks and separates the teeth; in Turkey it is also called kürsör. The puller (elcik) is the grip attached to the slider.
• Stops: The top stops at the upper end of the chain and, on a closed-end zipper, the bottom stop at the lower end.
• Box and pin: Found only at the lower end of an open-end (separating) zipper.

Tooth type and end construction

By tooth type

Sources: YKK, 2022; Coats; YKK Türkiye; Ankara University lecture notes.

By end construction

• Closed-end: The bottom stop joins the two tapes at the bottom; the zipper opens only from the top. Used in skirts, trousers and pockets.
• Open-end (separating): A box and pin at the lower end let the two halves separate completely. Used on the front of jackets and coats.

For selection criteria for each type and a starting table by product, see the zipper types and sizes guide. For suppliers, see the zipper manufacturers and suppliers page.

What does the size number mean?

The number is a size class tied to the width of the interlocked teeth on a closed zipper; as it rises, the teeth get wider and the expected strength increases. It does not equal millimeters exactly: in one manufacturer’s catalog, a No. 5 coil zipper falls in the 5.5–7.0 mm band (YKK Fastening Catalogue, January 2022). The catalog data is given as an example, not as a brand recommendation.

In Turkey, nylon zippers are also referred to by a “tip” (type) number, and these numbers may not follow the same scale as international numbers (Ankara University Open Courses, Fermuar). So in an order, also write the tooth type and the tooth width in millimeters.

How it differs from similar terms

• Buttons and snap fasteners: TDK defines a button (düğme) as a small fastener sewn onto a garment and a snap fastener (çıtçıt) as a two-part metal fastener. Both fasten at specific points; a zipper closes continuously along the edge.
• Hook-and-loop tape: A tape with hooks on one face and loops on the other that grips when pressed together. Velcro is a brand name; the generic name is hook-and-loop (Velcro Companies). TDK records one meaning of the Turkish word cırcır as zipper; in quotations and orders, write the technical description rather than everyday names.

Standard and nickel

For general-use zippers the European standard is EN 16732 (Slide fasteners (zips) – Specification). The standard gives performance levels and test methods for parts such as puller attachment, stops, box and slider lock, and also defines levels of dimensional stability and color fastness in washing and dry cleaning. According to the EVS record, the 2025 edition has been in force since May 15, 2025 and replaces the 2015 edition; it does not cover special-purpose zippers such as those for diving suits.

Zippers with metal parts also face a nickel restriction. In the EU, entry 27 of Annex XVII to the REACH Regulation limits the release of nickel from the skin-contact parts of articles intended to come into direct and prolonged contact with the skin to 0.5 µg per square centimeter per week; zippers used in clothing are in the entry’s list of examples (Regulation (EC) 552/2009). In Turkey the same restriction appears in entry 27 of Annex-17 of the KKDİK Regulation, the Regulation on the Registration, Evaluation, Authorisation and Restriction of Chemicals (Official Gazette, June 23, 2017, issue 30105 (repeated)). The reference measurement method is EN 1811; the European Commission updated the reference to EN 1811:2023 on December 20, 2023 (C/2023/1604). This information is valid as of the date of this entry (October 2026) and legislation may change. Confirm the current text from the legislative source and from your accredited test laboratory; for an export or compliance decision, consult a chemicals-regulation specialist.

Frequently asked questions

Who invented the zipper?

Naming a single inventor varies by source; patent documents are a safer basis. US patent No. 504,038, granted to Whitcomb L. Judson in 1893, protects a device for shoes that interlocks and separates two-part clasps with a guide block slid over them. Gideon Sundback’s “Separable fastener” patent (No. 1,219,881), filed in 1914 and granted in 1917, describes a fastener for garments in which interlocking elements on two flexible tapes are clasped and unclasped by a sliding device.

What should you watch for when washing a garment with a zipper?

Keep the zipper closed during washing, drying and dry cleaning; an open zipper can snag other garments and be damaged (YKK, 2022). A zipper with aluminum-alloy teeth is not suited to harsh processes such as jeans washing and re-dyeing (YKK, 2022). The ironing limit varies with the tooth type (YKK, 2022); the values are given in the guide linked above.