Mtedza wosalowa madzi umagwiritsidwa ntchito mosiyanasiyana ndipo umabwera mosiyanasiyana kuti ukwaniritse zofunika zosiyanasiyana. Kumvetsetsa zodziwika bwino ndikofunikira pakusankha bwino ndikugwiritsa ntchito mtedza wosalowa madzi.
1. Diameter
Kuzama kwa mtedza wosalowa madzi ndizomwe zimafunikira. M3, yokhala ndi mainchesi ake ang'onoang'ono, nthawi zambiri imagwiritsidwa ntchito pazida zing'onozing'ono kapena pomwe malo ndi ochepa, monga kulumikizana kwamkati m'zida zazing'ono zamagetsi. M4 ndi M5 amagwiritsidwanso ntchito kwambiri polumikiza zigawo zing'onozing'ono zomwe sizikhala ndi katundu wambiri koma zimafuna madzi. M6 ndi M8 ndizofala kwambiri pamakina, zida, ndi zida zina, zomwe zimatha kupirira zovuta zina ndi torque. M10 ndi M12 nthawi zambiri amagwiritsidwa ntchito pamapulogalamu omwe amafunikira mphamvu yolumikizirana kwambiri, monga zida zamagalimoto ndi kulumikizana ndi zida zamafakitale.
2. Ulusi Pitch
Kuthamanga kwa ulusi kumatsimikizira kuthamanga ndi kulondola kwa kuwombera pakati pa nati ndi bawuti. Mtedza wosakanizidwa ndi madzi amakhala ndi ulusi wofanana ndi ma diameter osiyanasiyana. Kutsika kwa ulusi kumakhudza kulimba kwa nsonga pakati pa nati ndi bawuti komanso kukhazikika kwa kulumikizana. Zing'onozing'ono za ulusi zimalola kusintha bwino komanso kukwanira bwino, ndipo nthawi zambiri amagwiritsidwa ntchito pamapulogalamu omwe amafunikira kulondola kwambiri. Ulusi wokulirapo umalola kuti zibowole mwachangu, zomwe zimawapangitsa kukhala oyenera kugwiritsa ntchito komwe kuli kofunikira.
3. Kutalika
Kutalika kwa mtedza wosalowa madzi ndizomwe zimafunikira. Kutalika kofanana kumayambira mamilimita angapo mpaka makumi a mamilimita. Nthawi zambiri,{2}} mtedza wosalowa madzi ndi wochepa. Mwachitsanzo, mtedza waung'ono wosalowa madzi pazida zamagetsi ukhoza kukhala pakati pa 3 ndi 8 mm wamtali. Komabe, mtedza wosalowa madzi wopangidwa kuti usavutike kwambiri kapena umafuna kukhazikika kwa kulumikizana kumatha kufika 10 mpaka 20 mm kapena kupitilira apo.