As the name suggests, a ring stretcher is a tool that can stretch or shrink a ring.
Use the upper part for stretching.
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It cannot be adjusted too drastically, but if you want to make it just a little bit larger, use this.
Use the lower part for shrinking.
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The true circle is mortised. It is also used when squeezing a ring into a perfect circle before welding, which is in the shape of a droplet, when making a ring.
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It is a heavy tool, so please be careful!
Talk about tools used for ring stretcher and engraving