Cable tie types under UL 62275: what Type 1, 2, 21, 2S and 21S mean

The Type designations come from the standard for cable ties used in electrical installations. Internationally that is IEC 62275, Cable ties for electrical installations. In North America it was adopted as a harmonized standard: UL 62275 in the United States, CSA C22.2 No. 62275 in Canada and NMX-J-623-ANCE in Mexico. Cable tie requirements in the older UL 1565 / CSA C22.2 No. 18.5 standard for positioning devices were retired in June 2014, so current listings refer to 62275.

The system works on declared ratings. The manufacturer declares a Type, a minimum loop tensile strength, temperature limits and optional ratings such as UV resistance, and the tests in the standard confirm or reject those declarations. When a third-party certifier's mark appears alongside the Type and ratings, the mark attests that the declarations were verified for that product.

Loop tensile strength is the reference strength: the force a closed tie withstands when pulled from the inside, which loads the strap and the locking mechanism together. The standard is explicit that this number does not indicate long-term static load-bearing capability, which is why the Types focus on whether a tie keeps its rating after conditioning rather than on the headline number alone.

IEC 62275 contains only Type 1 and Type 2. The US and Canadian editions add Types 11, 21, 2S and 21S, so you will mainly see those four designations on products certified for the North American market.

The second digit "1" is about the plastic, not the environment. Type 11 and Type 21 ties must be molded from a polymer that has its own UL Recognition under the plastics program (category QMFZ2), evaluated to UL 746A and UL 746B or CSA C22.2 No. 0.17. Two practical consequences follow. The tie's declared maximum operating temperature cannot exceed the material's long-term Relative Thermal Index for strength, and the material carries a flammability rating of at least HB under UL 94, with V-2, V-1 or V-0 also acceptable. Type 1, 2 and 2S ties instead pass a needle flame test on the finished product.

The "S" suffix means support. Every Type is evaluated for securing, which means holding a cable in position. A cable tie that bears the weight of cable or flexible conduit between supports is doing a different job, and electrical codes treat it differently. Type 2S and 21S ties must declare at least 50 lb (220 N) and hold that load for five minutes instead of one. The support rating applies to flexible conduit, flexible tubing and cable as the installation code allows; UL notes that rigid conduit is not covered.

The Type tells you how the tie holds its strength. The rest of the marking tells you where it can be used. UL's guidance is blunt on this point: a rating only applies when it is marked on the package.

• Maximum operating temperature: the highest continuous temperature after installation. Common declarations run from 50°C to 150°C.
• Minimum operating temperature: the lowest temperature the installed tie is rated to see, verified by an impact test after cold exposure. Common declarations run from 0°C down to -60°C.
• Minimum installation temperature: only marked when declared below 0°C. If nothing is declared, NEMA advises treating 0°C (32°F) as the lowest temperature to install at.
• Resistance to ultraviolet light: optional for nonmetallic ties, tested with xenon-arc exposure and water spray, and marked as UV resistant or for outdoor use.
• Air-handling spaces: AH-1 (metallic, may go inside ducts) or AH-2 (nonmetallic, tested to UL 2043 for heat and smoke release, for spaces used for air such as above hung ceilings but not inside fabricated ducts). Only Types 2, 21, 2S and 21S can carry these.
• Bundle diameter range, mounting surfaces for fixing devices and, for metallic ties, corrosion resistance.

UL certifies cable ties as positioning devices. In the United States, Listed products fall under category code ZODZ and carry the Listed or Enhanced UL Certification Mark; they are intended for field or factory installation in accordance with the National Electrical Code. Recognized components fall under ZODZ2 and carry the backward "UR" mark; they are intended for factory installation inside another product, and they come with conditions of acceptability that the end-product maker has to meet. The Canadian equivalents are ZODZ7 and ZODZ8.

In UL Solutions' application guide for this category, Types 1 and 11 appear under Recognized and Types 2, 21, 2S and 21S under Listed. That matters when a code section asks for a listed product. For example, recent NEC editions allow nonmetallic-sheathed cable to be secured and supported with "cable ties listed and identified for securement and support", which points to an S-rated listed tie. Even with a listing, the authority having jurisdiction makes the final call on whether a product is acceptable for an installation.

A Type designation on a web page or a UL logo in a product photo is not proof. Certification belongs to a specific company, a specific product line and specific catalog numbers, and it is easy to check.

1. 1Find the certification details on the smallest package: the UL mark, the Type, the declared ratings and, ideally, the manufacturer's UL file number (it usually starts with E).
2. 2Open UL Product iQ (productiq.ulprospector.com) and sign in; basic searches need a free account.
3. 3Search by the file number, the company name or the category code ZODZ (ZODZ2 for Recognized components, ZODZ7 for Canada).
4. 4Confirm the company named in the record is the one that makes or private-labels the tie you are buying.
5. 5Find the exact catalog or part number in the record, and check that its Type, loop tensile strength, temperature ratings, UV rating and any AH marking match what the package says.
6. 6If you cannot find the part number, ask the supplier for the file number and the listing record before you buy. A listing for a different product line from the same factory does not cover the tie in your hand.

Most cable ties in the world are used for general bundling where no code asks for a listed product: organizing a shop, tying down tarps, dressing wire harnesses that are not part of a building wiring system. For that work, pick length, strength and color on their merits. When a tie becomes part of an electrical installation, the table below is a reasonable starting point, but the installation code, the project specification and the inspector come first.

Nirah sells standard 100% nylon PA66 ties for general-purpose use. Our product pages do not list a UL 62275 Type, a UL listing or temperature and flammability ratings, so where a job calls for any of those, choose a tie whose listing you have verified using the steps above.