Half round sterling wire is 18 gauge AWG, which is xmm x xmm. Inside diameter is mandrel size, not actual ring size. These rings are sold individually.

Half round Argentium wire is 18 gauge AWG, which is xmm x xmm. Inside diameter is mandrel size, not actual ring size. These rings are sold individually.

Half round silver filled wire is 18 gauge AWG, which is xmm x xmm. Inside diameter is mandrel size, not actual ring size. These rings are sold individually.

Half round yellow gold filled wire is 18 gauge AWG, which is xmm x xmm. Inside diameter is mandrel size, not actual ring size. These rings are sold individually.

Half round rose gold filled wire is 18 gauge AWG, which is xmm x xmm. Inside diameter is mandrel size, not actual ring size. These rings are sold individually.