The path through the fastener - not the joint between the sheets.

The body is a cup rather than a tube, so nothing passes through the rivet itself.

The interface between the two sheets is a separate path and needs its own sealant, gasket or lap detail.

A closed-end rivet in an unsealed lap joint gives a watertight fastener in a leaking seam.

That distinction is worth being explicit about, because it is a common misunderstanding.

Where both must be sealed, the rivet and the joint detail are specified together.

Because a loose metal stub inside an enclosure is a hazard, not an untidiness.

Open-end rivets hold the mandrel stub by friction alone, and vibration can free it.

In electrical enclosures a loose conductive fragment can bridge terminals.

In ducting, hydraulic and pneumatic systems it becomes debris in the flow.

In hollow sections it rattles, which is a persistent complaint in vehicle bodies.

Closed-end rivets trap the stub inside a sealed cavity where it cannot go anywhere.

Yes - the closed body is stiffer and there is more material to upset, so setting force is higher.

Hand tools reach their limit at smaller diameters than with open-end rivets.

Steel and stainless closed-end rivets generally need a lever, pneumatic or hydraulic tool.

Under-setting is the usual result of an inadequate tool, and it looks the same as a correct set from the front.

Checking the tool's stated capacity against the largest rivet in use is worth doing before buying.

Nosepieces are size-specific, as with any blind rivet.

Narrower than an open-end rivet of the same diameter, because the closed cavity limits how the body collapses.

That makes correct grip selection more important rather than less.

It is also a common reason a closed-end substitution into an existing design does not drop straight in.

The two failure modes are the same as for any blind rivet and equally invisible.

More part numbers are therefore needed to cover a given range of thicknesses.

Where thickness varies widely, a sealed joint may be better achieved another way.

Vehicles, marine work, enclosures, ducting and electrical equipment - anywhere the fastener must not be a path.

Vehicle bodies use them where water would otherwise track through the panel.

Marine and coastal work uses them for the same reason and for the corrosion benefit.

Electrical enclosures use them mainly for mandrel retention.

Ducting and air handling use them to prevent leakage at every fixing.

Anywhere an ingress protection rating is claimed, the fixings have to be consistent with it.

With more difficulty than an open-end rivet - more material, a retained mandrel and a sealed cavity.

The mandrel head is inside the closed body, so there is more to drill through.

There is no mandrel hole to centre the drill on, which makes it easier to wander and damage the parent hole.

Centre-punching the head before drilling helps considerably.

If the hole is enlarged, a larger or large-flange replacement is needed.

Where joints will be opened routinely, threaded fasteners are a better starting point.

The same reasoning applies - match the sheets, or use stainless where they differ or the joint is exposed.

Sealed joints are frequently in wet or exposed positions, which raises the corrosion stakes.

A riveted seam has many holes and therefore many potential galvanic couples.

Stainless closed-end rivets need more setting force again, which pushes the tool requirement up.

Aluminium closed-end rivets set easily and suit aluminium sheet.

The mandrel material matters as much as the body, since it stays permanently inside the joint.