branding iron 
noun
A metal implement which is heated and used to brand livestock (or, in former times, criminals or slaves).Later Charley and my husband heated branding irons and burned as many brands as they could remember all over the logs....
- The slave trade is also explored through a selection of sometimes harrowing photographs: a coffle chain with shackles, the Cape Coast dungeon doors in Ghana, and a slave branding iron.
- To get the best brands, we hold the cooled branding irons on the hide for 60 seconds.