harden◼◼◼[UK: ˈhɑːd.n̩] [US: ˈhɑːr.dn̩] steel◼◼◻[UK: stiːl] [US: ˈstiːl] toughen◼◼◻[UK: ˈtʌf.n̩] [US: ˈtʌf.n̩] temper◼◼◻[UK: ˈtem.pə(r)] [US: ˈtem.pər] quench◼◻◻[UK: kwentʃ] [US: ˈkwentʃ] soak◼◻◻[UK: səʊk] [US: soʊk] season◼◻◻[UK: ˈsiːz.n̩] [US: ˈsiːz.n̩] | 