13mm Pharmaceutical Vial Seals & Caps

This hub lists every 13mm vial cap and seal Autofits manufactures: the FlipTop® Optima aluminium-plastic flip-off, the all-aluminium tear-off, and the tear-down construction. The 13mm seal is the small-neck closure used on low-fill injectable and lyophilised vials, crimped over a 13mm rubber stopper to ISO 8362-1. Use the matrix below to compare construction, dimensions, and opening method before you specify a part.

Key takeaways

Autofits offers the 13mm size in three constructions: FlipTop® Optima flip-off, all-aluminium tear-off, and FlipTop® Tear-Down.
All three crimp over a standard 13mm vial neck and stopper to ISO 8362-1; the difference is how the seal opens and whether it has a plastic top.
The 13mm Optima inner aluminium diameter is 13.36 mm (min) with a total seal height of 7.62 to 8.38 mm and 6 taper bridges.
Maximum opening force for the 13mm range is 30 N, the lowest in the Autofits line because the small diameter uses fewer bridges.
Standard packing is 15,000 seals per box (5,000 x 3 bags), with Tyvek bagging and RTU or RTS delivery available.
For the full size index see products by size; for all constructions see the products page.

Which Autofits products come in 13mm

The 13mm neck is supported across the aluminium-plastic and all-aluminium families:

FlipTop® Optima (aluminium-plastic flip-off): a moulded plastic button you flip up to expose a small injection point while the aluminium skirt stays crimped. Available in Bridge, Button, and Flower designs and glossy, matte, embossed, or printed finishes. See FlipTop® Optima 13mm.
Tear-off (all-aluminium): a one-piece aluminium seal with no plastic top, opened by tearing the metal away to expose the stopper. See tear-off seals.
FlipTop® Tear-Down (aluminium-plastic): a PP disc riveted to the aluminium; the disc is pulled and rotated anticlockwise so the whole seal comes off, used mainly for oral vaccinations. See tear-down seals.

13mm product matrix

All dimensions in millimetres, transcribed from the Autofits engineering drawings.

Product	Construction	Inner Ø (D1)	Total height	Alu thickness	How it opens	Product page
FlipTop® Optima	Aluminium-plastic flip-off	13.36 (min)	7.62–8.38	0.16–0.20	Flip plastic button up (6 taper bridges)	Optima 13mm
Tear-off	All-aluminium	13.20–13.60	6.90–7.70	(on request)	Tear aluminium top away (2 bridges)	Tear-off seals
FlipTop® Tear-Down	Aluminium-plastic	13.30–13.50	6.80–8.30	0.18–0.22	Pull PP disc, rotate anticlockwise, full seal off	Tear-down seals

How to choose between the 13mm constructions

For routine injectables, colour-coded identification, and a small exposed injection point, the FlipTop® Optima flip-off is the usual 13mm choice; the Button design also gives intrinsic tamper evidence through its 12-stem flower under the button disc. Where the full stopper needs to be exposed, the all-aluminium tear-off removes the metal top entirely. Where the whole seal should come off in one action, for example certain oral vaccination workflows, the FlipTop® Tear-Down uses a PP disc that is pulled and rotated anticlockwise. Construction choice also depends on whether the line needs an aluminium-plastic or an all-aluminium closure and on the sterilization route. Share the application and we can recommend a part.

Vial neck and ISO 8362-1 sizing for 13mm

A 13mm seal is specified to the vial neck finish, not to the vial volume. The dimensions of the glass neck (crown bore, flange diameter, and flange thickness) are defined in ISO 8362-1, and a 13mm seal is dimensioned to crimp cleanly over a matched 13mm stopper seated in that neck. In practice the 13mm finish appears on smaller injectable and lyophilised vials. Always confirm that the seal, the rubber stopper, and the glass vial share the same nominal neck finish so the crimp seats square and the rolled skirt forms a consistent residual seal force.

Opening force and standard packing for 13mm

From the FlipTop Seals dossier, the 13mm size has a maximum opening force of 30 N. Opening force varies with the number and taper of the bridges, and the 13mm Optima uses 6 taper bridges. The lower force suits low-fill vials handled by hand at point of use.

Standard packing is 15,000 seals per box, supplied as 5,000 x 3 bags in a 420 x 270 x 320 mm box. Tyvek bagging is available, and seals can be delivered Regular, Ready-to-Use (RTU, gamma or ETO sterilized), or Ready-to-Sterilize (RTS), double-bagged for aseptic areas. Minimum order quantity, colour selection, and lead times are confirmed on enquiry.

Quality and standards

13mm seals are produced under the Autofits quality system: ISO 9001:2015, ISO 14001:2015, and ISO 15378:2017 (GMP), supported by a Drug Master File (DMF 18100) and CFDA registration. The aluminium-plastic constructions follow ISO 15378:2017 and ISO 8362-6; the all-aluminium tear-off relates to ISO 8362-3. PP discs are moulded in-house on Japanese Toyo injection machines, washing is fully automated, and every seal passes 100% high-speed camera inspection. Assembly takes place in an ISO Class 8 cleanroom inside the 75,000 sq ft Nashik facility. AQL is critical nil, major NMT 2.5%, minor NMT 4%, and is tailorable. Full certification detail is on the quality page.

Frequently asked questions

What is a 13mm vial cap used for?

A 13mm vial cap is the small-neck closure used on low-fill injectable and lyophilised vials. It crimps over a 13mm rubber stopper seated in a 13mm vial neck finish to ISO 8362-1, compressing the stopper against the glass to form the sterile seal. Autofits supplies the 13mm size as a flip-off, a tear-off, or a tear-down.

What is the difference between the 13mm constructions?

The FlipTop® Optima flip-off has a plastic button you flip up to expose a small injection point while the aluminium stays crimped. The all-aluminium tear-off has no plastic top and is opened by tearing the metal away. The FlipTop® Tear-Down has a PP disc that is pulled and rotated anticlockwise so the whole seal comes off. All three seal the vial the same way through the crimp; they differ in how you open them.

What is the opening force of a 13mm seal?

The maximum opening force for the 13mm range is 30 N. This is the lowest in the Autofits line because the small diameter uses fewer taper bridges. Actual force varies with the bridge count and taper of the specific design.

How are 13mm seals packed and delivered?

Standard packing is 15,000 seals per box, supplied as 5,000 x 3 bags in a 420 x 270 x 320 mm box. Tyvek bagging is available. Seals can be supplied Regular, Ready-to-Use (gamma or ETO sterilized), or Ready-to-Sterilize, double-bagged for aseptic filling areas.

Are 13mm seals available in different colours?

Yes. The seals are available in a wide range of colours, matte or glossy, customised to requirement, and the aluminium can be printed or embossed. Specific colours and any printing are confirmed at the quotation stage.

Sources

Autofits engineering drawings and FlipTop Seals product dossier (on file).
ISO: ISO 8362-1, Injection containers and accessories, Part 1: Injection vials made of glass tubing (https://www.iso.org/standard/63461.html)
ISO: ISO 15378:2017, Primary packaging materials for medicinal products, GMP requirements (https://www.iso.org/standard/70326.html)

*Last updated: 2026-06-26. This page is general technical information, not regulatory or compliance advice; confirm current dimensions, standard editions, and requirements with Autofits and the issuing bodies.*