Ma hope o ka hoʻopio ʻana a me ka hoʻomaloʻo ʻana, hana ʻia ka paʻakikī o ka induction mid frequency, e hōʻoiaʻiʻo ana i ka ikaika o ke kumu a me ke kūpaʻa o ka ʻili o waho.
Ma hope o ka carburization, hana ʻia ka paʻakikī induction waena alapine (mid frequency) o ke kumu pine i loko a me waho, e hōʻoiaʻiʻo ana i ka paʻakikī o ke kumu kūpono a me ke kūpaʻa o ka ʻaʻahu ʻana o nā ʻili o loko a me waho.
