1/8" OD Tubing Induction Coil Mandrel

Wanted to wind a 1.29 uH coil for my induction brass anneal project (see https://www.mgnz-makes.com/project-overview)

Easily wound a very close to 1.29 uH 7.5 turn coil with an ID of 28mm.

Copper Tubing Used: https://www.amazon.com/gp/product/B07QDL1RQG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1