Mutuwar samarwa tana buƙatar dogaro da naushi (latsa) don samar da ƙarfi, girman mutuwa daban, nau'in tsari yana buƙatar zaɓar naushi daban don dacewa. Zaɓin naushi mai ma'ana na iya rage farashi da adana albarkatu.
Ana auna babban mizanin bugun zaɓi na mutuƙar nauyi, wanda yawanci ana samunsa ta hanyar adadin ƙarfin ɓoyewa, ƙirƙirar ƙarfi, danna matsi da ƙwanƙwasa ƙarfi. Babban shi ne blanking karfi.
Ba'a gyara ƙarfin ƙarfin ɓoyewa ba, kuma canjin sa a cikin aikin hatimi kamar haka: lokacin da naushin ya fara tuntuɓar samfurin hatimin, blanarfin ɓoye koyaushe yana cikin ƙaruwa. Lokacin da naushi ya shiga game da 1/3 na kaurin kayan, ƙarfin ɓoyewa ya kai iyakar ƙimar. Bayan haka, saboda bayyanar yanki yanki na ƙarfi, ƙarfin zai ragu a hankali. Sabili da haka, lissafin ƙarfin ɓoyewa shine lissafin matsakaicin ƙarfin ɓoyewa.

Lissafi na blanking da karfi
Tsarin kirgawa na karfi mara karfi: P = L * t * KS kg
Lura: P shine ƙarfin da ake buƙata don ɓoyewa, cikin kilogiram
L shine kewayen yankin kayan kwalliyar kwalliya, a cikin mm
T shine kaurin kayan, a cikin mm
KS shine ƙarfin ƙarfin abu, a cikin kg / mm 2
Gabaɗaya, lokacin da aka yi samfuran ɓoye da ƙaramin ƙarfe, ƙayyadadden ƙimar ƙarfin ƙarfin kayan abu kamar haka: KS = 35kg / mm2
Misali:
Yi tsammani kaurin kayan t = 1.2, kayan yana da farantin karfe mai laushi, kuma samfurin yana buƙatar bugi farantin rectangular mai siffar 500mmx700mm. Menene ƙarfin ɓoyewa?
Amsa: gwargwadon lissafin lissafi: P = l × t × KS
L = (500 + 700) × 2 = 2400
t = 1.2, Ks = 35Kg / mm²
Saboda haka, P = 2400 × 1.2 × 35 = 100800kg = 100t
Lokacin zaɓar nauyin, ya kamata a ƙara 30% a gaba. Saboda haka, nauyin ya kai tan 130.