Pallavi the bezel or collette being a little small is a correct step

provided the seat for the stone is not yet cut or added on. A bezel

can then be tapped up to the exact size and adjusted to the exact

profile on an oval mandrel, on the horn of a bench anvil, or by

pinching all around with a pair of flat/round-nose pliers.

Calculating the length of strip for an oval is quickest by treating

it as a circle. If the oval is bent into a round, the diameter of the

round will be the long length of the oval + the short width of the

oval divided by two. In your example 6 + 4 / 2 = 5. Make a round

bezel of 5 diameter and then force it into an oval. The length of

strip needed for a round of 5 diameter is D, so it is x 5

Is 22/7 or 3.14 so 3.14 x 5 = 15.7… but if you use just = 3 the

bezel will be a little smaller and can be stretched up to “fitting

size”!

Alastair