- February 18, 2026
A pressure vessel is only as reliable as its weakest component. Dished ends, which are the curved closures that cap either end of a cylindrical pressure vessel, are among the most structurally critical parts in the entire assembly. Get the dished end manufacturing process right, and you get a vessel head that distributes stress evenly, maintains integrity under pressure, and performs safely for decades. At Dished Ends International, this is what we do, and is what we have done for decades.
In this article, we will walk you through the manufacturing process from raw material to finished product.
What Are Dished Ends?
Dished ends – also called pressure vessel heads, tank heads, or end caps – are shaped metal components used to close and seal the ends of cylindrical vessels. They appear across petrochemical, chemical processing, pharmaceutical, food and beverage, water treatment, and defence industries.
The term “dished” refers to the curved, concave shape. This curvature is engineered to distribute internal pressure loads across the surface of the head, preventing the stress concentrations that cause failure. The specific geometry determines the type of dished end, each with its own pressure rating, cost profile, and fabrication requirements.
Hot Pressing vs Cold Pressing
The two primary methods to form a dished end each have a direct impact on the mechanical properties and suitability of the finished end.
Hot pressing forms the dished end at elevated temperatures within the material’s normalising range, eliminating the residual stresses that would otherwise be built in during forming. The result is a finished product with superior ductility and improved resistance to cracking which is preferred for high-pressure, high-temperature applications such as petrochemical storage, pressure reactors, and defence systems.
Cold pressing forms the end at room temperature. It is faster and more cost-effective, making it the common choice for standard and low-to-medium pressure applications. The trade-off is that cold pressing introduces stresses into the component, meaning that post-forming heat treatment may be required depending on the material and degree of deformation.
For a detailed comparison of both methods, see our article on hot pressed vs cold pressed dished ends.
The Manufacturing Process: Step by Step
1. Material Selection
Dished ends are manufactured from carbon steel, stainless steel, duplex stainless steel, aluminium, and titanium, depending on the pressure rating, operating temperature, and chemical environment. We supply ends with material thicknesses from 2mm to 300mm, with all materials tested prior to forming using UT, RT, MT, PT, and TOFD methods.
2. Blank Cutting
The flat plate is cut into a circular disc (the blank) sized to account for the material drawn into the curved profile. Cutting is carried out by plasma, laser, or oxy-fuel methods depending on material and thickness.
3. Forming
This is the most critical stage. In hot pressing, the blank is heated to within the normalising range before being formed under a shaped die. We have refined a one-press technique that minimises heat exposure and maintains material quality. In cold pressing, forming may progress over multiple operations, particularly for non-standard sizes.
4. Flanging
A straight flange, known as the skirt, is formed around the perimeter. This is the section welded to the cylindrical shell of the vessel. Dished-only ends are produced without this flange, used in applications such as truck tanks and silos.
5. Trimming and Edge Preparation
The outer edge is trimmed to exact dimensions and prepared with the correct weld bevel profile, ensuring accurate fit-up during vessel fabrication.
6. Heat Treatment (Where Required)
Cold-pressed ends that exceed the allowable strain limit of the material, as defined by the applicable code, require stress-relief annealing to restore material properties. Hot pressed ends do not, as no stresses are built in during forming.
7. Surface Treatment
Depending on the application, this may include shot blasting, pickling (for stainless steel), or prime coat painting for carbon steel ends.
8. Quality Inspection
Every dished end undergoes rigorous inspection before leaving the facility, covering crown and knuckle radius, surface condition, weld seam integrity, and dimensional compliance.
Dished End Types
The process above produces a range of geometries to suit different applications. Torispherical dished ends are the most cost-effective option for standard industrial applications, featuring a shallower profile that reduces material and forming costs. Semi-ellipsoidal dished ends have a deeper profile that distributes stress more evenly, making them the preferred choice for high-pressure applications such as chemical reactors and compressed gas vessels. Dished-only ends are used where the connection design does not require a conventional flange.
View our full product range for the complete selection.
Why the Manufacturing Process Matters
For pressure vessel engineers and fabricators, understanding how a dished end is made directly informs purchasing decisions, design compliance, and safety outcomes. A component that has been incorrectly formed, insufficiently tested, or manufactured outside the relevant standard introduces risk into a vessel operating under significant pressure and temperature.
When evaluating dished end manufacturers, look for: control over the forming method, heat treatment applied where required, a rigorous NDE and inspection regime, standards compliance, and genuine experience in pressure vessel fabrication across the material grades and geometries you need.
We supply dished ends from 89mm to 10 metres in diameter, delivering across Australia, New Zealand, and globally. To discuss your requirements, call us on 0427 240 339 or request a quote online.