Static Mixing Nozzle Types: Bayonet, Bell-Mouth, Cross & Square Connections Explained

The main static mixing nozzle types are sorted by two things buyers often blur into one list: the connection that locks the nozzle onto your cartridge (bayonet, bell-mouth, or integral nut) and the element geometry inside it (helical, square/quadro, or cross-grid). “Bayonet, bell-mouth, cross, and square” actually span both axes, two are how the static mixer attaches, two describe the mixing element. Get the connection wrong and the order go back: cross-brand compatibility is the single biggest reason a two-component (2K) consumables order is returned. This guide separates the axes, maps the cross-brand fit, decodes the part numbers, and shows how to identify your system from the cartridge base.

What a Static Mixing Nozzle Is, and Why the Connection Matters

A static mixing nozzle is a disposable plastic tube filled with internal elements that blend a two-part adhesive’s resin and hardener as you dispense, with no moving parts. Those elements split and recombine the two streams repeatedly, so the bead leaves the tip fully mixed — pick the wrong one and it cures off-ratio, or the whole order comes back.

The same component is sold under many names — static mixer nozzle, static mixing tube, mixing tip, mixing nozzle tips, disposable static mixer — and cheaper versions are marketed as generic static mixing nozzles. They’re all nozzles for two-part adhesives: tubes that mix two-part glue, sealers and foams at the point of dispense, whether the job is called glue mixing or 2-part dispensing. The University of Michigan Visual Encyclopedia of Chemical Engineering catalogues the same split-and-recombine principle. Whatever the label, fit depends on three things agreeing — the cartridge system, the connection type, and the mix ratio.

The 3-Match Rule

For a full primer on what these consumables do, see our overview of two-component static mixing nozzles. This article go one level deeper: the physical type categories themselves.

Takeaway: “Type” isn’t one axis – sort by how it connects first, then by the element inside.

Connection Types: How the Nozzle Locks On

The connection (or inlet) is the part of a static mixing nozzle that snaps onto the cartridge outlet. There are three working types- bayonet, bell-mouth, and integral nut- and the bell family further divides into round, square and rotary sub-connections. Bayonet inlets twist-and lock and accommodate 9-50 mL cartridges, bell inlets sit with a retaining nut and dominate 200 mL and larger, integral (threaded) inlets serve large cartridges directly and lacks a separate nut.

The Connection-vs-Geometry Split

Here’s the distinction most spec sheets bury: of the four terms buyers list – bayonet, bell-mouth, cross, and square – only bayonet and bell-mouth are connections. “Cross” and “square” describe the mixing element (covered next), with one exception: on patented interlock cartridges, a “cross” or keyed coding feature is the anti-cross-contamination lock, not an element. Patent records make the locking mechanics explicit- a two-component cartridge attachment patent describes pushing the element axially onto a cone, then turning it clockwise: a textbook bayonet engagement.

Takeaway: Sort by connection family (bayonet / bell-mouth / nut), then by cartridge size band- that pair determines the fit 80% of the time.

Element Geometry: Helical, Square (Quadro) & Cross-Grid, and the Pressure-Drop Tradeoff

Inside the tube, each element is a baffle that does the mixing; geometry determines mix quality, nozzle length, and squeeze force. Helical (spiral) elements use continuous twisted blades, square (quadro) elements use orthogonal channels that redirect the flow at sharp intersections, cross-grid elements use an intersecting lattice for multi-directional redistribution. Each shuffles the same two-part stream a different way, and each trades pressure drop against length- a 24-element helical at an 8 mm bore pushes harder than a 16-element square of the same diameter.

Geometry also sets dispensing force. More elements, a smaller inner diameter, or a higher-viscosity material all raise pressure drop — which is why a long, fine epoxy nozzle that a pneumatic dispenser pushes easily can be a fight for a manual dispenser, and why spray-bead nozzles run a wider bore. If the bead stalls or starts off-ratio, the element and diameter choice — not the adhesive — is usually the cause.

Takeaway: Choose helical for reliable, well-understood mixes; choose square (quadro) mainly to shorten the tube and trim a little waste — and budget the pressure drop against your gun.

Cross-Brand Compatibility: Mixpac, 3M, Nordson, Cox & Loctite

Can I connect a static mixer or cartridge from one company to a gun from another? Generally, yes, but only if the cartridge system, connection type, and ratio match. Sulzer’s Mixpac (medmix) system set has become the de facto interface standard, and other manufacturers such as 3M, Nordson, and Cox simply built their specific name conventions and adhesive cartridge types over that same standard set of connections, across adhesive cartridges from 50 mL up to 200mL cartridges and beyond. One exception to this open-system rule is patented: the Mixpac B-System and F-System use proprietary connection designs that generally do not cross-fit other manufacturers.

The Cross-Brand Fit Key

Takeaway: Cross compatible consumables can be used on most open system guns (A/C/K, 3M EPX, Nordson, Cox), but B and F connection nozzles are typically patented, proprietary designs that are OEM-only.

How to Read a Mixer Part Number

Static mixing nozzle part numbers fall into two families, and only one is readable. Geometry-coded numbers encode the specs directly; opaque catalog numbers do not, so you cross-reference them against a table. Patent filings such as US 7,484,881 B2 show why it is the geometry — jacket, element cross-section and count — that fixes the spec, not the catalog digits.

The 2K Mixer Part-Number Decoder

Take Sulzer/Infinity-style codes such as MFQX 08-24T or EDSQ05-7YLS: the series letters give the family and geometry (MFQX = F-system quadro), the first number group is the inner diameter, the second is the element count, and the suffix flags the tip or connection. EDSQ05-7YLS reads as a 5.3 mm inner diameter, 7-element square nozzle. That is decodable.

Now the trap: many catalog numbers encode nothing. A 3M static mixing nozzle SKU such as 08193 or 08194 is just a catalog number — the digits do not tell you the diameter or element count, and neither do entries like 2397788 or HEAE00001. For those, you read the specs from the data sheet, not the number. When you replace a nozzle, match the geometry-coded spec or look up the opaque SKU in a cross-reference — guessing from the digits is how the wrong tube arrives.

Top tip: Geometry encoded numbers (MxQ/Mx H, EDSQ), are decoded to diameter-element-tip; non-transparent SKUs (3M 08193) require lookup.

Identify Your Connection From the Cartridge Base

If you possess a cartridge or gun with no documents, using base profile (shape) is currently your quickest way to the proper static mixer. This eliminates a number of the possibilities to a single connection family, although base profile doesn’t tell all; the best fit often hinges upon minute coding within the unit.

The Bayonet-to-Square Base ID Flowchart

Why limit ourselves to “likely?” Because within that patent sit those fatal details. A cartridge-mixer coding patent, for example, tells you the fit of can be determined by coded ledges, diameter of inner tube (relative to outer by 1:2 – 1:10), width of the groove the inlet slides in and in this case, a 1/4 turn orientation -none of which are evident on what can appear as two identical bases. It’s the difference between an innocent looking nozzle and one that simply refuses to dock. Indeed, 2K consumables come back to us more than anything on account of this compatibility mismatch, so when a base has ambiguous labeling we’ve our sales reps pull a photo of the base from the customer along with the code in the base, then have our engineer check fit before processing the order.

Takeaway: Base shape lets you pick a family fast, but you still verify the fine coding before ordering — a visual match alone is necessary, not sufficient.

Sizing the Mixer: Element Count, Diameter, Length & Ratio

When your connections are in place, the sizing determines mix quality. Levers are number of elements, inner diameter, and length, read off of the curve from your materials viscosity and mix ratio. Use the following curves as general guidance, and not as gospel; as one engineer from Sulzer Mixpac told us in an industry article, crude formulas, such as “all epoxies use 24 elements” are potentially misleading; overall mix quality is a function of viscosity, diameter, element count and geometry together, a point the academic work on helical static mixers reinforces.

Worked example. A urethane at a wide 10:1 ratio sits at the top of the band. Start at about 24 elements; if the first beads streak or cure soft, step up toward 36 and widen the inner diameter so the higher count does not spike back-pressure beyond what a manual gun can push. If the squeeze gets too hard, move to a pneumatic two-component dispensing gun rather than dropping element count and risking an off-ratio mix. For diameter, thin materials (under 5,000 cps) run 0.093″–0.25″ (2.4–6.4 mm); thick materials (over 50,000 cps) need 9.3 mm or more. As a reference point, a typical 50 mL epoxy nozzle carries 17 elements at a 3.0 mm inner diameter with a 0.090 inch (2.3 mm) outlet orifice.

Advice: Begin with mid-band, adjust count, diameter, and gun together – don’t chop elements to fit a squeeze.

Choosing the Right Nozzle for Your Adhesive

Selection is connection + geometry + size read against your chemistry and your rate of production. This grid is a rapid first pass; for a deeper buyer’s walk-through of an exact scenario, we have a whole tutorial on how to select a static mixer. One caveat underlies it all: A nozzle that fits isn’t necessarily a nozzle that mix well.

“We view the static mixer as a central part of the adhesive system. Choosing a device with the proper configuration shouldn’t be an afterthought.”

Ken Lambert, Product Manager, ITW Plexus, in ASSEMBLY Magazine

Takeaway: Pick the connection and size for the chemistry, then confirm the mix — for cross-system jobs lean on Mixpac- and Nordson-compatible cartridges.

What’s Changing in 2K Mixer Connections

The new shape of connectivity isn’t born of new geometry-but of IP. Square (quadro) elements is actually the second-generation next step but (as we discussed above) its benefits were marginal. What this means for purchasers on the ground is a significant legal shift that’s beginning to move the question of supply away from “who’s my OEM?” toward “of all my formats which is open and which is locked?”.

Patent status alone is no guarantee that any branded interface is now freely open — expiry, assignment and litigation are legal facts, not usage data; Sulzer Mixpac’s EP 0 815 929 B1, still listed active in 2024, is a case in point. But trend counts for buying. Before your next buy, categorize your cartridge fleet into open systems (A/C/K, 3M EPX, Nordson, Cox) where interchangeable consumables are easy, and patented systems (Mixpac B/F) where you’ll want to verify OEM and freedom-to-operate conditions in writing. Market itself is stable not booming – trackers have the static mixer group growing in low-to-mid single digits year-on-year growth through to early 2030s, with projections that differ depending on analyst – the advantage must come from procurement discipline not from a forthcoming rush of new interface types.

Key take away: Assess at what point your configurations open vs oem-locked, it won’t be a new geometry where future 2026 buyers find value, avoid future returns.

Frequently Asked Questions