34mm Pharmaceutical Vial Seals & Caps

This hub lists the 34mm vial cap and seal Autofits manufactures. The 34mm size is currently offered as the FlipTop® Optima aluminium-plastic flip-off, the largest size in the Optima range and the closure for the largest-neck injectable, lyophilised, and reconstitution vials, crimped over a 34mm rubber stopper to ISO 8362-1. Other 34mm constructions are available on request. Use the detail below to specify the part.

Key takeaways

Autofits offers the 34mm size as the FlipTop® Optima flip-off; it is the largest size in the Optima range.
Other 34mm constructions (pull-ring, tear-down, all-aluminium tear-off) are available on request.
The seal crimps over a standard 34mm vial neck and stopper to ISO 8362-1.
The 34mm Optima inner aluminium diameter is 33.60 to 34.00 mm with a total seal height of 15.00 to 16.00 mm and 8 taper bridges.
The 34mm top finish is glossy; finishes and colours are customised to requirement.
Opening force and standard pack quantity for the 34mm size are available on request, 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 34mm

The 34mm neck is currently supported by one construction, with the other constructions quotable on request:

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. The 34mm is the largest size in the range. See FlipTop® Optima 34mm.
Other constructions (pull-ring, tear-down, all-aluminium tear-off): not published at 34mm in the current dimension set, but available on request. Confirm feasibility and dimensions with Autofits at enquiry.

34mm 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	33.60–34.00	15.00–16.00	0.20–0.25	Flip plastic button up (8 taper bridges)	Optima 34mm
Pull-ring, tear-down, tear-off	On request	available on request	available on request	available on request	available on request	Products

The 34mm Optima has an outer disc diameter of 35.50 to 36.50 mm and a glossy top.

Vial neck and ISO 8362-1 sizing for 34mm

A 34mm 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 34mm seal is dimensioned to crimp cleanly over a matched 34mm stopper seated in that neck. The 34mm 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 34mm neck finish so the crimp seats square and the rolled skirt forms a consistent residual seal force.

Opening force and standard packing for 34mm

The FlipTop Seals dossier publishes opening force and standard packing up to the 32mm size, so there is no published 34mm opening-force or pack-quantity figure. Both are confirmed on enquiry. The 34mm Optima uses 8 taper bridges, and actual opening force varies with the taper and count of bridges in the specific design.

Seals ship in a 420 x 270 x 320 mm box, and Tyvek bagging is available. Seals can be delivered Regular, Ready-to-Use (RTU, gamma or ETO sterilized), or Ready-to-Sterilize (RTS), double-bagged for aseptic areas. Standard pack quantity, minimum order quantity, colour selection, and lead times are confirmed on enquiry.

Quality and standards

34mm 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 construction follows ISO 15378:2017 and ISO 8362-6. 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 34mm vial cap used for?

A 34mm vial cap is the largest-neck closure used on high-fill injectable, lyophilised, and reconstitution vials. It crimps over a 34mm rubber stopper seated in a 34mm vial neck finish to ISO 8362-1, compressing the stopper against the glass to form the sterile seal. Autofits supplies the 34mm size as the FlipTop® Optima flip-off; other constructions are available on request.

What constructions does Autofits offer in 34mm?

The 34mm size is currently offered as the FlipTop® Optima aluminium-plastic flip-off, the largest size in the Optima range. Pull-ring, tear-down, and all-aluminium tear-off constructions are not in the published 34mm dimension set but are available on request.

What is the opening force of a 34mm seal?

The dossier publishes opening force up to 32mm, so a 34mm opening-force figure is available on request. The 34mm Optima uses 8 taper bridges, and actual force varies with the taper and count of the bridges in the specific design.

How are 34mm seals packed and delivered?

The standard pack quantity for the 34mm size is available on request. Seals ship in a 420 x 270 x 320 mm box and 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 34mm 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. The 34mm Optima carries a glossy top as standard. 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.*