Technical notes
Notes
These are the explanations we find ourselves giving most often. They are deliberately short, and they stop where the honest answer becomes “it depends on your specific case”.
Every note is also available as a PDF at the foot of its page.
Galvanic corrosion in mixed-metal assemblies
Why a stainless fastener in an aluminium bracket is a design decision, not a detail.
Chloride pitting and the limits of PREN
A single number is useful for ranking alloys and dangerous for specifying them.
Passivation of stainless steel, and why it fails
The film is only as good as the surface it forms on and the oxygen it can reach.
Sacrificial anodes or impressed current?
Choosing between the two systems is mostly a question of current demand and access.
Reading ISO 12944 before you write a coating specification
Durability ranges are not warranties, and the category is not a formality.
Hydrogen embrittlement in high-strength fasteners
Three conditions have to coincide. Removing any one of them prevents the failure.