32mm Pharmaceutical Vial Seals & Caps

This hub lists every 32mm vial cap and seal Autofits manufactures: the FlipTop® Optima flip-off, the FlipTop® Pull-Ring flower, the tear-down flower, and the all-aluminium tear-off. The 32mm seal is the large-neck closure for high-fill injectable, lyophilised, and reconstitution vials, crimped over a 32mm 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 32mm size in four constructions: FlipTop® Optima flip-off, FlipTop® Pull-Ring flower, tear-down flower, and all-aluminium tear-off.
All four crimp over a standard 32mm vial neck and stopper to ISO 8362-1; they differ in how the seal opens and whether it carries a plastic top.
The 32mm Optima inner aluminium diameter is 32.10 to 32.90 mm with a total seal height of 14.30 to 15.50 mm and 12 taper bridges.
Maximum opening force for the 32mm range is 65 N, the highest in the Autofits line because the large diameter uses more bridges.
Standard packing is 1,400 seals per box (700 x 2 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 32mm

The 32mm neck is supported across all four constructions, with the larger designs built as flowers:

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. Bridge, Button, and Flower designs; glossy, matte, embossed, or printed finishes. See FlipTop® Optima 32mm.
FlipTop® Pull-Ring flower (aluminium-plastic): the whole seal detaches once the PP disc is detached; you pull the aluminium ring and open anticlockwise. Built as an 8-fin flower at 32mm. See pull-ring seals.
Tear-down flower (aluminium-plastic): a PP disc riveted to the aluminium; the disc is pulled and rotated anticlockwise so the whole seal comes off. Built as an 8-fin flower at 32mm. See tear-down seals.
Tear-off (all-aluminium): a one-piece aluminium seal opened by tearing the metal top away to expose the stopper. See tear-off seals.

32mm 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	32.10–32.90	14.30–15.50	0.21–0.25	Flip plastic button up (12 taper bridges)	Optima 32mm
FlipTop® Pull-Ring flower	Aluminium-plastic	32.15–32.40	14.30–15.30	0.20–0.26	Pull alu ring, open anticlockwise, full seal off (8 fins)	Pull-ring seals
Tear-down flower	Aluminium-plastic	32.40–33.15	14.30–15.30	0.20–0.26	Pull PP disc, rotate anticlockwise, full seal off (8 fins)	Tear-down seals
Tear-off	All-aluminium	32.40–32.60	13.00–13.60	(on request)	Tear aluminium top away	Tear-off seals

The 32mm tear-off has a perforation diameter of 17.80 to 18.20 mm.

Vial neck and ISO 8362-1 sizing for 32mm

A 32mm seal is specified to the vial neck finish, not to the vial volume. The crown bore, flange diameter, and flange thickness of the glass neck are defined in ISO 8362-1, and a 32mm seal is dimensioned to crimp cleanly over a matched 32mm stopper seated in that neck. The 32mm finish appears on the largest injectable and reconstitution vials, where the wide crown bore allows full withdrawal or reconstitution. Always confirm that the seal, the rubber stopper, and the glass vial share the same nominal 32mm neck finish so the crimp seats square and the rolled skirt forms a consistent residual seal force.

Opening force and standard packing for 32mm

From the FlipTop Seals dossier, the 32mm size has a maximum opening force of 65 N. This is the highest in the Autofits line because the large diameter uses more bridges; the 32mm Optima uses 12 taper bridges. The higher force reflects the larger crimp area on a wide-neck vial.

Standard packing is 1,400 seals per box (700 x 2 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

32mm 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 32mm vial cap used for?

A 32mm vial cap is the large-neck closure used on high-fill injectable, lyophilised, and reconstitution vials. It crimps over a 32mm rubber stopper seated in a 32mm vial neck finish to ISO 8362-1, compressing the stopper against the glass to form the sterile seal. Autofits supplies the 32mm size as a flip-off, a pull-ring flower, a tear-down flower, or an all-aluminium tear-off.

What is the difference between the 32mm 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 FlipTop® Pull-Ring flower and the tear-down flower both let the whole seal detach once the PP disc is removed, the pull-ring by an aluminium ring and the tear-down by pulling and rotating the disc. The all-aluminium tear-off has the metal top torn away entirely. All four seal the vial through the crimp; they differ in how you open them.

What is the opening force of a 32mm seal?

The maximum opening force for the 32mm range is 65 N, the highest in the Autofits line. The 32mm Optima uses 12 taper bridges, and actual force varies with the taper and count of the bridges in the specific design.

How are 32mm seals packed and delivered?

Standard packing is 1,400 seals per box (700 x 2 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.

Why are the larger 32mm seals built as flowers?

At 32mm the pull-ring and tear-down designs are built as 8-fin flowers. The fins give the aluminium the controlled tear and lift path needed on a wide-neck seal, so the whole seal can detach cleanly once the PP disc is removed. The flip-off Optima at 32mm uses 12 taper bridges for its larger crimp.

Are 32mm 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.*