Rivets for Permanent Joints in Sheet Metal and Construction Profiles
A rivet does one thing well: permanent joint without rear access. You can undo a screw. A rivet - not easily. That's the advantage and the limitation.
Two main families:
Pop rivets (blind rivets) - the most common in construction and installation. Rivet gun: rivet goes through the hole in both parts, mandrel pulls through, the head expands on the back face and snaps off. Diameter: 3.2, 4.0, 4.8, 6.4mm. Length is chosen by total thickness of the materials being joined.
Material:
- Aluminium - light, moderate strength. Not for exterior in contact with steel or stainless - galvanic corrosion.
- Galvanised steel - stronger, for construction and thicker sheet.
- Stainless A2/A4 - for outdoor, marine, permanent moisture exposure.
Solid rivets - for structural joints under dynamic load. Driven with hammer and bucking bar. Rarely used in general construction - more common in aerospace and industrial structures.
Large-flange pop rivets - 12-14mm head prevents pulling through thin material (thin sheet, polycarbonate).
Rivet length: total material thickness + 1.5x diameter to form the closing head. For two 2mm sheets with a 4mm rivet: 2+2+6 = 10mm.
Grip length (beyond the head) = total material thickness + 1.5x rivet diameter to form the closing head. For two 2mm sheets with a 4mm rivet: 2+2+6 = 10mm total length. Every rivet pack states the grip range it covers.
Steel for joints under higher mechanical load or with thicker sheet. Aluminium for light joints, thin aluminium sheet, or where weight matters. Important: don't combine aluminium rivets with steel parts in outdoor conditions - galvanic corrosion will attack the shank.
Drill rivet adaptors exist and work fine for medium volumes. For intensive work, pneumatic or electric rivet guns are faster and more accurate. Manual hand rivet pliers are for occasional use - up to about 100 rivets per session.
Yes, but with destruction. Drill through the rivet head using a bit sized to the mandrel diameter - the head pops off and the mandrel falls through. Place a new rivet in the same hole if the dimensions allow. Rivets aren't designed for removal - if you need the joint to come apart, use a bolt and nut.
Pop rivets in galvanised steel or stainless steel, 4.8 or 6.4mm diameter, length chosen for the combined sheet and profile thickness. Outdoors - hot-dip galvanised or stainless is mandatory. Aluminium rivets on steel roof sheeting outside will corrode in 2-3 seasons.
