20mm All-Aluminium Tear-Down Seal
The 20mm all-aluminium tear-down seal is a one-piece AA8011 closure opened by tearing a perforated band of the metal down so the whole seal releases from the vial neck. It is not the FlipTop® Tear-Down, which is a separate aluminium-plastic product with a polypropylene disc riveted to the aluminium and opened by twisting anticlockwise. External aluminium diameter is 20.50 to 20.70 mm with a 12.90 to 13.20 mm perforation, seal height 7.50 to 8.50 mm, gauge 0.18 to 0.22 mm, two taper bridges, maximum opening force 35 N.
This page covers the all-metal version only. If your specification means the riveted PP disc and the anticlockwise twist-off, go to the FlipTop® Tear-Down; for the rest of the all-metal family, see the tear-down seal range.
Key takeaways
- All aluminium (AA8011), no polypropylene disc, so it falls under ISO 8362-3, not the combination-cap standard.
- External Ø 20.50–20.70 mm, perforation Ø 12.90–13.20 mm, seal height 7.50–8.50 mm, gauge 0.18–0.22 mm, two taper bridges.
- Maximum opening force 35 N; standard packing 6,000 per box (2,000 in each of two bags), shipper 420 × 270 × 320 mm.
- Opening breaks the bridges and releases the whole closure, exposing the stopper.
- Two products carry the name “tear-down”: check construction and opening action before ordering.
- Supplied Regular, Ready-to-Use (gamma or ETO sterilized) or Ready-to-Sterilize.
What is an all-aluminium tear-down seal?
An all-aluminium tear-down seal is a single drawn AA8011 shell that crimps over the rubber stopper to seal the vial, with a perforated band and two taper bridges torn downward to release the entire closure from the neck.
The metal is not the sterile barrier. The barrier is the stopper held in compression by the crimped skirt. The 12.90 to 13.20 mm perforation and the two bridges define how the metal gives way, so the tear runs a controlled path. Once the bridges break, the seal lifts off and the stopper is accessible.
That full release separates a tear-down from a tear-off, which removes only the perforated top and leaves the skirt crimped on the neck. The read-out is on tear-off vs tear-down. Vial necks follow ISO 8362-1.
All-aluminium tear-down vs FlipTop® Tear-Down
Two distinct products share the name. The version on this page is one-piece aluminium with nothing moulded on it. The FlipTop® Tear-Down is an aluminium-plastic combination cap with a PP disc riveted on. Specifying the wrong one gets the wrong opening action and the wrong standard.
| All-aluminium (this page) | FlipTop® Tear-Down, 20 mm | |
|---|---|---|
| Construction | One-piece aluminium | Aluminium, PP disc riveted on |
| Plastic component | None | Polypropylene disc |
| Opening | Tear band down, seal releases | Open disc, pull and rotate anticlockwise |
| External Ø aluminium | 20.50–20.70 mm | 20.00–20.60 mm |
| Second diameter | Perforation 12.90–13.20 mm | Disc 22.00–23.00 mm |
| Total height | 7.50–8.50 mm | 8.80–9.80 mm assembled |
| Typical use | Plastic-free injectables | Oral vaccinations |
| Standard | ISO 8362-3 | ISO 8362-6 |
Full specifications: FlipTop® Tear-Down.
Specifications and sizing
Controlled dimensions from the Autofits engineering drawings, with opening force and packing from the dossier. The standard shipper box is 420 × 270 × 320 mm.
| Property | Value |
|---|---|
| Nominal size | 20 mm |
| External / inner Ø aluminium (D1) | 20.50–20.70 mm |
| Perforation Ø (D2) | 12.90–13.20 mm |
| Aluminium / total seal height | 7.50–8.50 mm |
| Aluminium thickness | 0.18–0.22 mm |
| Bridges | 2 taper |
| Max opening force | 35 N |
| Standard packing (per box) | 6,000 (2,000 × 2 bags) |
| Construction | One-piece aluminium, no plastic disc |
| Material | AA8011 aluminium with epoxy lacquer |
| Standard finish | Double-side silver lacquer |
Because there is no disc, aluminium and total height are the same figure. Other sizes and Tyvek bagging are available on request. Comparable 20 mm closures are indexed on the 20 mm by-size page.
Materials and quality
The shell is AA8011 aluminium alloy, conforming to EN 15088:2005 with EN 10204-3.1 certification and testing to BS EN 485-2:2008, REACH and RoHS compliant. The coating is an epoxy lacquer conforming to 21 CFR 175.300, silver both sides as standard and pigmentable for colour identification. Heavy metals (chromium-VI, cadmium, mercury, lead) are capped at 100 ppm total, and the materials are BSE/TSE-free to EMEA/410/01 rev. 3.
The 0.18 to 0.22 mm gauge is heavier than the 0.16 to 0.20 mm used on the 20 mm tear-off, which lets the bridges hold through capping and still break predictably on opening. Seals pass through automated washing, 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 NMT 2.5%, minor NMT 4%. The certification set is on the quality page.
Forms of supply
The 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 after capping, and 2 years for Ready-to-Use. Order quantities, lead times and pricing are available on request.
Applications
The all-aluminium tear-down suits injectable and parenteral vials needing a plastic-free closure and full stopper exposure: veterinary multidose formats, research reagent and diagnostic presentations, and diluent vials whose contents are transferred rather than drawn through a septum. Because the bridges must break before the seal releases, an unopened vial is self-evidencing. For the all-metal alternative that leaves the skirt in place, see tear-off seals, or the product range.
Frequently asked questions
What is the difference between the all-aluminium tear-down seal and the FlipTop Tear-Down?
They are two different products. The all-aluminium tear-down is one piece of AA8011 aluminium with no plastic, opened by tearing a perforated band down until two taper bridges break and the seal releases. The FlipTop Tear-Down is an aluminium-plastic cap with a polypropylene disc riveted on, opened by working the disc then rotating anticlockwise, and used mainly for oral vaccinations. The first relates to ISO 8362-3, the second to ISO 8362-6.
What are the dimensions of the 20mm all-aluminium tear-down seal?
External aluminium diameter is 20.50 to 20.70 mm, perforation diameter 12.90 to 13.20 mm, seal height 7.50 to 8.50 mm and aluminium thickness 0.18 to 0.22 mm, with two taper bridges. There is no disc, so aluminium and total height are the same figure.
What is the opening force of the 20mm tear-down seal?
The maximum opening force is 35 N. Opening force varies with the number of bridges and the length of the tear path, and this design uses two taper bridges.
How many 20mm tear-down seals are in a box?
Standard packing is 6,000 seals per box, as 2,000 in each of two bags, in a 420 by 270 by 320 mm shipper. Tyvek bagging is available.
Does the all-aluminium tear-down seal contain any plastic?
No. It is made entirely from AA8011 aluminium with an epoxy lacquer coating, with no polypropylene disc and no plastic top. The tear-down with a riveted plastic disc is the separate aluminium-plastic FlipTop Tear-Down.
Is it available in other sizes?
Autofits holds full engineering-drawing data for the 20 mm all-aluminium tear-down seal. Other sizes are available on request; share your vial neck finish, stopper and delivery form and the technical team will confirm fit and supply.
Related reading
- Tear-down seals: the full range
- FlipTop® Tear-Down (aluminium-plastic)
- Tear-off seals
- Tear-off vs tear-down seals
- 20 mm seals by size
- ISO 8362-3: aluminium caps for injection vials
- All product families
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 8362-6, Caps made of aluminium-plastics combinations for injection vials (https://www.iso.org/standard/52806.html)
- ISO 8362-1, Injection vials made of glass tubing (https://www.iso.org/standard/74398.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.*
