Ngā rautaki whakapapa mō ngā waka toa me ngā waka hīkoi, ahakoa kāore i whakaritea i te āhua o te ipurangi, he momo hanga nui tēnā i hanga mai i ngā kaihanga matua hei whakangungu me te whakatumanu. He whanau e rua tuatahi ngā pūtango (tirohia ai ki te SAE J2429), he whakapapa 2-ira ki te kingpin, e tino whakaaetia ana mo ngā huanga porowhita e tuwhera ana ki te 20 tonne me ngā mahi drawbar e 80 tonne. He pūtango e hiki ana i te rautaki whatiwhati me te tohu whakamahere mō te karo, ko te rautaki uku (he upoko ake i te uku) e whakaiti haere i te tirotiro. Mo ngā tūranga nui rawa, he kingpin 3.5-ira ngā pūtango e toru, e whakapai ana i te hunga porowhita ki te 35 tonne. Ko te rautaki whakapapa i whakatakoto ki runga i te kauhanga kuhuawe (e taea ana te whakatika 500mm mua-muri) hei whakatika i te whakawāhanga o ngā taumata. He whakaaetanga anti-rattle (rubber buffers) hei whakaiti i te kōrero me te wehe, me te ao tūnga 1 million i ngā wāhanga whakapapa. Kei te whakaaetanga ia ngā pūtango ki ngā paerewa EC 1230/2009. Tuku tonu ki tā tātau tari parts hei whakahoki i ngā whakariterite o ngā rautaki whakapapa, ka kitea ai te mass, ngā taurea whakatakoto, me te whakaaetanga ki ngā momo toa rerekē.