Abubuwan da ba daidai ba: Ƙaƙƙarfan ƙaƙƙarfan ƙaƙƙarfan ƙaƙƙarfan ƙaƙƙarfan ƙaya ne.Gabaɗaya, su ne nau'i-nau'i waɗanda ba su dace da ma'auni na waje da kayyade na kasa ba, wato, duk wani nau'i na waje wanda girmansa ya bambanta da ma'auni na kasa.Babban fasalinsa shine ƙananan ƙarancin gabaɗaya, galibi don kayan aiki na musamman da lokatai na musamman, ƙananan batches, da samfuran gwaji na sabon bincike da kayan haɓaka kayan aiki na mafi yawan;amma saboda rashin sikelinsa da samar da tsari, babu kamfanonin samarwa da yawa da farashi mai yawa , Farashin ya fi tsada.Daidaitaccen bearings: Diamita na ciki ko na waje, nisa (tsawo), da girman daidaitattun bearings sun dace da GB / T273.1-2003, GB / T273.2-1998, GB / T273.3-1999 ko wasu ma'auni masu dacewa.Girman samfurin.Rashin daidaituwa ba daidai ba ne wanda bai dace da girman da tsarin daidaitaccen albashi ba, wato aunawa gwargwadon buƙatun abokin ciniki.Wanda ba daidai ba a ciki da waje 49, daidaitaccen 50, duk sauran abubuwa iri ɗaya ne.49 ba daidai ba ne, kuna buƙatar bin girman da tsarin tsarin a cikin littafin abokin ciniki, in ba haka ba ba ku sani ba idan 49 na ƙasa ne ko kuma ba daidai ba.Sauran tsarin sun bambanta.Alal misali, akwai da yawa karfe ball rollers.Ko ƙasa da haka.Wannan ba kasafai, gabaɗaya na iya zama cikakken suna na duniya ba daidai ba ne.