13mm Tear-Off Seal for Pharmaceutical Vials

The 13mm tear-off seal is a one-piece, all-aluminium vial closure: an AA8011 aluminium shell crimped over the rubber stopper, with a perforated metal top that is torn completely away at point of use. There is no polypropylene disc and no plastic button anywhere on the part. Inner aluminium diameter is 13.20 to 13.60 mm, total seal height is 6.90 to 7.70 mm, and the design carries two bridges with a maximum opening force of 30 N.

This page covers the 13 mm dimensions, materials, quality position, forms of supply and applications. For the opening mechanism, the tamper-evidence behaviour and the other two sizes, see the tear-off seal range.

Key takeaways

The 13 mm tear-off seal is all aluminium (AA8011) with no plastic component, which places it under ISO 8362-3 rather than the aluminium-plastics combination standard.
Inner Ø 13.20–13.60 mm, total seal height 6.90–7.70 mm, two bridges.
Maximum opening force 30 N, the lowest in the tear-off range, because the 13 mm top presents the smallest tear area.
Standard packing is 15,000 seals per box (5,000 in each of three bags), in a 420 × 270 × 320 mm shipper.
Supplied Regular, Ready-to-Use (gamma or ETO sterilized) or Ready-to-Sterilize, double-bagged for aseptic areas.
Produced under ISO 15378:2017 GMP with 100% high-speed camera inspection and AQL critical nil.

What is a 13mm tear-off seal?

A 13mm tear-off seal is the all-metal closure for a 13 mm neck vial: a deep-drawn aluminium shell whose skirt rolls under the neck flange during capping to compress the rubber stopper against the glass, and whose upper face is perforated so the metal top can be torn off by hand.

The seal is not the sterile barrier. The barrier is the stopper held in compression by the crimped skirt, and the crimp survives opening. The perforation only defines where the metal separates, so the tear runs along a controlled line rather than ragged across the face. Once the top is away, the stopper is exposed for the needle or for full removal.

The 13 mm format is the small-volume vial size. Match the seal to a 13 mm vial finish and a 13 mm stopper of the same nominal diameter; vial necks follow ISO 8362-1. The difference from the aluminium-plastic FlipTop® range is that nothing here is moulded: one drawn piece of metal, no disc to rivet, no assembly step.

Specifications and sizing

Controlled dimensions for the 13 mm tear-off seal, from the Autofits engineering drawings, with opening force and packing from the product dossier. The standard shipper box is 420 × 270 × 320 mm.

Property	Value
Nominal size	13 mm
Inner Ø aluminium (D1)	13.20–13.60 mm
Total seal height	6.90–7.70 mm
Bridges	2
Max opening force	30 N
Standard packing (per box)	15,000 (5,000 × 3 bags)
Construction	One-piece aluminium, no plastic disc
Material	AA8011 aluminium with epoxy lacquer
Standard finish	Double-side silver lacquer

Perforation diameter and aluminium gauge for the 13 mm part are available on request. Tyvek bagging is offered as an alternative to the standard polybag. Sizing across the range is set out on the 13 mm by-size index; the larger formats are the 20mm tear-off seal and the 32mm tear-off seal.

Materials and quality

The shell is AA8011 aluminium alloy, conforming to EN 15088:2005 with EN 10204-3.1 certification and mechanical testing to BS EN 485-2:2008, and is REACH and RoHS compliant. The coating is an epoxy lacquer conforming to 21 CFR 175.300, silver on both sides as standard and pigmentable for colour identification in a wide range of colours, matte or glossy, customised to requirement. Heavy metals (chromium-VI, cadmium, mercury, lead) are held to a maximum 100 ppm total, and the materials carry a BSE/TSE-free declaration to EMEA/410/01 rev. 3.

Seals pass through fully automated washing to remove particles, then 100% high-speed camera inspection. Production runs under ISO 15378:2017 GMP with ISO 9001:2015 and ISO 14001:2015 certification, a Drug Master File (DMF 18100) and CFDA registration, at the 75,000 sq ft Nashik facility. AQL is critical nil, major not more than 2.5%, minor not more than 4%, tailorable to your specification. The full certification set is on the quality page.

Forms of supply

The 13 mm tear-off seal ships Regular (clean, bulk-packed, for washing and sterilization in house), Ready-to-Use (washed and assembled in an ISO Class 8 cleanroom, gamma or ETO sterilized, double-bagged for aseptic areas) and Ready-to-Sterilize. Shelf life is 3.5 years before capping for non-irradiated seals, plus 5 years after capping, and 2 years before capping for Ready-to-Use. Minimum order quantities, lead times and pricing are available on request.

Applications

The 13 mm tear-off seal is used on small-volume injectable and parenteral vials where an all-metal closure is preferred or where the stopper has to be fully exposed after opening. Typical categories are research reagent and diagnostic presentations, veterinary products specified plastic-free, and small-fill injectables reconstituted at the bedside. For the wider catalogue, see the full product range.

Frequently asked questions

What are the dimensions of a 13mm tear-off seal?

The Autofits 13 mm tear-off seal has an inner aluminium diameter of 13.20 to 13.60 mm and a total seal height of 6.90 to 7.70 mm, with two bridges. Perforation diameter and aluminium gauge for this size are available on request.

What is the opening force of a 13mm tear-off seal?

The maximum opening force is 30 N, the lowest of the three tear-off sizes. Opening force varies with the number of bridges and the tear area, so a larger seal needs more force.

How many 13mm tear-off seals are in a box?

Standard packing is 15,000 seals per box, supplied as 5,000 in each of three bags, in a 420 by 270 by 320 mm shipper. Tyvek bagging is available as an alternative.

Does a 13mm tear-off seal contain plastic?

No. It is made entirely from AA8011 aluminium with an epoxy lacquer coating. There is no polypropylene disc and no plastic button. Closures with a moulded plastic top sit in the separate aluminium-plastic FlipTop range.

Which standard applies to a 13mm tear-off seal?

As an all-aluminium cap it relates to ISO 8362-3, aluminium caps for injection vials, and is produced under an ISO 15378:2017 GMP quality system. Vial necks follow ISO 8362-1. Aluminium-plastics combination caps relate to ISO 8362-6 instead.

Can the 13mm tear-off seal be supplied sterile?

Yes. It is offered Ready-to-Use, washed and assembled in an ISO Class 8 cleanroom, sterilized by gamma irradiation or ETO and double-bagged for aseptic filling. Ready-to-Sterilize and Regular forms are also available.

Sources

Autofits engineering drawings and FlipTop Seals dossier (working/spec-sheets/)
ISO 8362-3, Aluminium caps for injection vials (https://www.iso.org/standard/33804.html)
ISO 8362-1, Injection vials made of glass tubing (https://www.iso.org/standard/74398.html)
ISO 15378, Primary packaging materials for medicinal products (https://www.iso.org/standard/70729.html)
US FDA: 21 CFR 175.300, Resinous and polymeric coatings (https://www.ecfr.gov/current/title-21/part-175)

*Last updated: 2026-08-18. This page is general technical and product information, not regulatory or compliance advice. All dimensions are nominal drawing values; confirm current standard editions, your vial finish and your specification with the Autofits technical team before ordering.*