Many customers buy hemispheres rather than finished spheres, either because they cut their own artwork or because a half ball is what the design needs. Closing two halves into a true sphere depends almost entirely on the edge preparation.
Our spun hemispheres carry a 45° welding groove. The groove aligns the halves, gives the weld somewhere to go, and makes grinding and polishing straightforward afterwards. Hand assembled hemispheres do not have this and are much harder to close accurately.
Step By Step
Choose the forming route
Spun for welding into a sphere. Stamped for small sizes with a smooth face. Assembled only where no mould exists at that size.
Choose the thickness
Stay below your plasma cutter's maximum cut capacity to avoid heavy burrs. 6mm is common for fire pit work.
Fix and spot weld
Fix one hemisphere on the bench, load the second by crane onto position, then spot weld 5 to 8 points.
Full weld the groove
Run the full weld inside the 45° groove.
Cut before you grind
If you are cutting artwork, cut first. Some weld area will be removed by the cut, so final grinding after cutting saves time.
Grind and finish
Grind off welds and burrs on every cut edge, then paint or leave to patinate.
What This Covers
- 45° welding groove on spun hemispheres from ∅89mm to ∅3500mm
- Thickness 2mm to 16mm by spinning
- Stamped hemispheres ∅19mm to ∅700mm for small work
- Hand assembled hemispheres ∅200mm to ∅3500mm with no mould limit
Product Categories Involved
Carbon Steel Hemispheres
Spun half balls with a 45° welding groove up to 16mm thick the starting point for a fire pit ball or a welded sphere.
3 products
Stainless Steel Hemispheres
Stamped and spun half balls from ∅6mm to ∅3500mm for vessel ends mixing bowls ceiling domes and safety mirrors.
7 products
Brass Hemispheres
Mirror polished or raw H62 brass half balls for door knockers lampshades jewellery sculpture and church roofs.
4 products
Aluminium Hemispheres
Light aluminium half balls stamped to ∅700mm or hand assembled to ∅3500mm with powder coating for lighting.
2 productsExplore Further
Hemisphere To Sphere Assembly FAQ
Do I need the 45° groove?
Which thickness should I order?
Should I grind the weld before cutting the artwork?
What is the most economical size to order as a first sample?
Start With a Conversation
The cheapest change to a sphere project is the one made before production starts.