CFS Blind Fasteners & Rivets 2

Question 1

A 'Rivnut' (threaded insert or nutsert) is classified as a blind fastener because:

Accepted Answer

It is installed by pulling a threaded mandrel that deforms the insert body from one side, creating a nut thread

Answer

It uses a breaking mandrel identical to standard pop rivets

Answer

It requires no special installation tools

Answer

It can only be installed in thin sheet metal under 1mm

Question 2

According to IFI and industry standards, a blind rivet's nominal diameter is measured:

Accepted Answer

By the body (shank) outer diameter before installation

Answer

Across the set head on the accessible side

Answer

By the mandrel diameter after fracture

Answer

Across the blind-side bulge after installation

Question 3

What failure mode is most likely when a blind rivet is installed in a joint that exceeds the rivet's maximum grip range?

Accepted Answer

The rivet body will not fully collapse, leaving the joint under-clamped with a loose mandrel stub

Answer

The mandrel will not fracture during setting

Answer

The rivet head will pull through the material

Answer

The rivet body will fracture instead of the mandrel

Question 4

Which military or aerospace specification is commonly referenced for solid (non-blind) aluminum aircraft rivets, providing a baseline to which blind rivet specifications are often compared?

Accepted Answer

MS 20470 (AN470)

Answer

NAS 1738

Answer

ASTM A325

Answer

SAE J429

Question 5

A 'drive rivet' (or hammer-set rivet) differs from a pull-type blind rivet in that it is set by:

Accepted Answer

Driving a pin into the rivet body with a hammer or press, expanding the blind end

Answer

Pulling a mandrel with a pneumatic rivet gun

Answer

Threading a bolt through the rivet body

Answer

Applying heat to expand the rivet shank

Question 6

For a tri-fold (3-leg) blind rivet design, what is the main engineering advantage over a standard single-bulge design?

Accepted Answer

The three-petal blind-side flange distributes the clamp load over a larger area, improving performance in soft or thin materials

Answer

Three-fold rivets are smaller in diameter, reducing weight

Answer

Tri-fold rivets are easier to remove and reinstall

Answer

They are approved for use in flammable environments

Question 7

When inspecting a completed blind rivet installation, which visual indicator suggests the rivet has been properly set?

Accepted Answer

The mandrel head is flush with or slightly below the rivet head face, with a fully formed blind-side bulge

Answer

The mandrel is still visible and protruding above the rivet head

Answer

The rivet body shows longitudinal cracks along the shank

Answer

The material shows slight buckling around the rivet