Ring Pellet Mould - Whole Sizes

(2 Reviews)
£22.46 (Exc Tax)
£26.95 (Inc Tax)
Current Stock:

Never worry about metal clay shrinkage when you’re making rings again - the Ring Pellet Mould ensures your rings are perfectly sized every time!

A Ring Pellet (also called ring sizer, or ring stopper, shrinkage stopper), is a special pellet or plug that is placed inside a metal clay ring shank during firing to control the size. The pellet is made from a special material that does not shrink or burn during firing. Metal clay ring making can be hard to get right, this helps you get the right size every time.

As the metal clay sinters, it shrinks tightly around the pellet so the ring is the exact diameter of the pellet after firing. After cooling, the ring is put into water to dissolve the pellet. 

With this mould you can cast your own Ring Sizers as and when needed. A half sized mould creates one pellet of each whole size from H-X (4 to 12 in US sizes). We recommend using the Ultra Smooth Casting Powder for a really smooth pellet - just mix as directed and pour into the mould. 


  1. Make your ring as normal (please consult the clay manufacturer's instructions to figure out how many sizes it shrinks when fired, silver clay can shrink anything between 7-25% depending on brand and type). Don't build your ring directly on the Ring Sizer Pellet.

  2. Cast your ring pellet to the desired size.

  3. Once the ring and the pellet is fully dried, place the ring stopper pellet inside the ring and fire as per the silver clay's recommended firing schedule.

  4. After it’s fully cooled, place in a container of water to dissolve the pellet. 

*Never quench a ring with a pellet whilst hot as a potentially dangerous thermal shock can occur* 


  • Your ring pellet mould will last for years to come if well looked after.
  • Do not leave in direct sunlight. When not in use, wrap the mould in cling film, or place in its original box, or in a tightly sealed plastic container
  • Do not wrap in paper or leave sitting in paper (it will leach the oils from the mould and cause it to dry out)


These pellets are super-handy and will definitely give you an accurately sized ring every time. However, don't forget that stopping the clay from shrinking fully means you could create weak spots. Your clay wants to shrink, sintering and shrinking is what brings all the silver particles together to give you a strong silver piece. Please be extra careful with your shrinkage sizing when using pellets like this. 

Mould includes 9 Whole Sizes of Pellet, from H-X (4 to 12 in US sizes). This mould is also available in half sizes, click here.

Click here for more information 

Reviews (2)

So Pleased to have found this

Written by KC on 26th Sep 2019

I made a plaster cast of the sizes in order to make porcelain rings. This worked really well. It would be great if they did the same mould in larger sizes too.

Excellent Tool!

Written by undefined on 19th Dec 2016

Very easy to use and clean but requires a much thicker recipe than the stated guide. Took a few days not two hours as mentioned to set completely, I pop them out and dry them further in a cup warmer. Please let a have more CoolTools products please!

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