A clad plate is a metal plate made of two or more different metals that are permanently bonded together: a strong, economical base (usually carbon steel) and a thinner layer of a corrosion- or wear-resistant metal such as stainless steel, nickel alloy or titanium. Clad plates are also called clad steel plates or bimetallic plates. They give the performance of an expensive alloy at a fraction of the cost, because the alloy is only used where it touches the process medium.
Clad vs plated vs coated
The three terms are often confused. The difference is how thick the layer is and how it is attached:
| Clad | Plated | Coated | |
|---|---|---|---|
| How the layer is attached | Metallurgical bond between two solid metals | Thin metal layer deposited, usually electrochemically | Applied film: paint, polymer, thermal spray or hot-dip zinc |
| Typical layer thickness | Millimetres (e.g. 1–50 mm) | Micrometres | Micrometres to a few millimetres |
| Examples | Stainless-clad steel, titanium-clad steel, Triplate® | Chrome, nickel or zinc plating | Paint systems, epoxy lining, galvanizing |
| Durability | Permanent; the clad layer is a structural part of the plate | Wears or can be damaged; renewed by re-plating | Ages, can chip or wear; needs maintenance |
| Typical use | Pressure vessels, heat exchangers, reactors, ships | Decoration, wear surfaces, small parts | Corrosion protection of structures |
So clad is not the same as plated: plating is a thin surface finish, while cladding adds a full, bonded alloy layer that can be welded, formed and machined with the plate.
How clad plates are made
- Explosion cladding — a controlled detonation drives the clad metal onto the base at high speed, creating a solid-state metallurgical bond. Works for almost any combination, including titanium and aluminium on steel. Shockwave does this inside vacuum chambers. See explosion welding.
- Roll bonding — compatible metals are hot-rolled together at a steel mill.
- Weld overlay — the alloy is welded onto the base in layers.
Compare them in detail: explosion clad vs roll bonded vs weld overlay.
Typical materials
Clad layers include stainless steels (304L, 316L, 321), duplex and super duplex, nickel alloys (625, 825, C-276), titanium, zirconium, tantalum, copper-nickel and aluminium. Bases are usually pressure-vessel steels such as SA516 or P265/P355. See all clad plate material combinations.
What clad plates are used for
Pressure vessels, columns and reactors in oil and gas and chemical plants; heat exchanger tube sheets; desalination equipment; and transition joints that let engineers weld aluminium to steel. Read more on our clad plates page.
Frequently asked questions
What is a clad plate?
A plate of two or more different metals permanently bonded together: a strong base, usually carbon steel, and a thinner corrosion-resistant layer such as stainless steel, nickel alloy or titanium.
Is clad the same as plated?
No. Plating is a micrometre-thin surface layer, usually applied electrochemically. Cladding is a millimetre-thick alloy layer metallurgically bonded to the base and part of the plate structure.
What is the difference between cladding and coating?
A coating is an applied film such as paint, polymer or zinc that protects the surface. Cladding bonds a solid metal layer to the base, so it does not chip or wear off like a coating.
What is a bimetallic plate?
Another name for a clad plate: a plate made of two different metals bonded together.
How are clad plates made?
By explosion cladding, roll bonding or weld overlay. Explosion cladding works for the widest range of metals and thicknesses.
Written by Joeri Hofstede, CEO of Shockwave Metalworking Technologies — vacuum explosion welding specialists since 1985.