If the hole is very small the material you are brazing with should fill it. A small piece sheet metal can be brazed in place to cover larger holes.
Blanking and punching are both shearing operation. The difference is only in the scrap. In blanking what you cut out is of interest.In punching what you cut from is of interest.For example: You cut a hole in a sheet metal. If you are interested in the disc that is cut out, then the process is called blanking. The sheet metal with a hole through it is the scrap. If you are interested in the sheet metal that now has a hole through it, then the process is called punching. The disc is the scrap.
With duct tape I install and maintain duct work for a living if you want to seal the joints just wrap the tape around the duct. If you need to cover a hole you will need to screw a piece of metal on the duct over the hole and tape over the edges of your patch. this is the simplest and cheapest way I know to do it.
The molds should be sand coated insides and a hole upside mold then introduce the molten metal.
A tek screw is a screw that has a drill bit tip for a point rather than coming to a sharp point like a needle. These are self-drilling screws and need no pilot hole. Tek is a brand name for self-drilling screws as Kleenex is a brand name for nose tissue. self-drilling screws are similar to sheet metal screws but have a drill point instead of coming to a sharp point and will drill their own hole. This eliminates the need to pre-drill a pilot hole.
A plasma cutter.
use a punch press or drill it
If the hole is very small the material you are brazing with should fill it. A small piece sheet metal can be brazed in place to cover larger holes.
The best way to make a hole in sheet metal is to use a drill with a metal-cutting bit. This method is precise and efficient for creating clean holes in different sizes. Alternatively, if you need a larger hole, punching or burning with a plasma cutter can also be effective, depending on the thickness of the metal.
Yes.
As the circular metal sheet is heated, it expands uniformly in all directions, including the hole. However, since the hole is not a separate entity but simply a void within the metal, it does not grow smaller or larger. The hole appears to change size relative to the expanding metal because of the way our eyes perceive the interaction between the sheet and the hole.
I think you are referring to a method of locating a nut in a piece of sheet metal. A rivet head nut is a nut with has a small projection not much thicker than the sheet metal to which you intend to fit it. This projection fits through a pre made hole in the sheet metal, and the small projection is peened over (deformed by hammering) to fix the nut to the sheet.
It would get larger due to the expansion of the metal (see the related links)
A circular piece of metal with a hole in it.
drill small hole in old seal use sheet metal screw drill small hole in old seal use sheet metal screw
Blanking and punching are both shearing operation. The difference is only in the scrap. In blanking what you cut out is of interest.In punching what you cut from is of interest.For example: You cut a hole in a sheet metal. If you are interested in the disc that is cut out, then the process is called blanking. The sheet metal with a hole through it is the scrap. If you are interested in the sheet metal that now has a hole through it, then the process is called punching. The disc is the scrap.
When you heat a metal all of the atoms try to get further apart including those on the inside edge of the capacity. The only way to do this is by increasing the size of the capacity. You can see this in action if you've ever got a glass stuck inside another. The best way to separate them is to heat them up in hot water so that the outer glass expands. Not sure what "with capacity inside" means. When you heat a piece of metal with a hole in it, the hole gets bigger. Imagine a sheet of metal with a circle drawn on it. Heat it up. Everything expands, Including the circle. The same is true if you actually remove the metal from inside the hole.