How They Make Stainless Steel Spheres

There has been a small clip of an explosive going off in large spheres in various video compilations on Youtube late 2021. I did not know what the clip was or what was happening. So I started doing some research to explain it. I found a company in China who makes Stainless Steel Spheres for art sculptures. The companies name is Shenzhen Maoping Sculpture Arts, they have been making stainless steel sphere for 23 years and can create any size stainless Steel sphere up to 20 feet in diameter, all crafted by hand. it can take about 15 days for a 6 foot diameter sphere. Based off my research, there seems to be 4 common ways to create a hollow metal sphere, Spinning, Mold Pressing, Water Pressure Hydroforming and Explosive Hydroforming. This video shows explains what the compilation video was and shows the process of how to make a Stainless Steel Sphere using the Water Pressure Hydroforming method from start to finish. Thanks for watching. The 4 ways are = Spinning, Mould