The smaller your punch hole, the wider the band. A larger punch hole will produce more of a womens size ring. Here's how to get a 1/4" punch hole onto your mandrel.
No fancy tools coin ring - https://www.youtube.com/watch?v=548qCuDHe_Q
Annealing your coin. How hot is too hot? https://www.youtube.com/watch?v=eIEmmc0-lZY
Drift Pin Set - https://www.amazon.com/ATD-Tools-759-3-Piece-Taper/dp/B000OUUGCS/ref=sr_1_24?ie=UTF8&qid=1501431099&sr=8-24&keywords=drift+punch+set
Deluxe Coin Punch - https://www.etsy.com/listing/214631219/classic-self-centering-coin-ring-punch?ref=shop_home_active_44
Cheaper Coin Punch - https://www.etsy.com/listing/530378575/new-no-spacers-auto-punch-with-all-six?ref=shop_home_active_16
Compression Dies - https://www.etsy.com/listing/274571462/full-set-four-universal-reduction-dies?ref=shop_home_active_24
Folding Cones - https://www.etsy.com/listing/259053043/sale-universal-stabilizer-folding-cones?ref=shop_home_active_11
Rubber Sanding Mandrels - https://www.etsy.com/listing/267370914/sale-original-coin-ring-rounding?ref=shop_home_feat_4
Shaping Mandrel - https://www.riogrande.com/Product/Durston-Hardened-Ring-Mandrel-16/112575