Lub hardness ntawm lub sib tsoo log yog hais txog qhov nyuaj ntawm cov nplej abrasive nyob rau saum npoo ntawm lub sib tsoo log ntog tawm nyob rau hauv qhov kev txiav txim ntawm lub sib tsoo quab yuam. Lub softer sib tsoo log hardness txhais tau hais tias lub sib tsoo log abrasive nplej yog ib qho yooj yim mus poob, thiab ib tug nyuaj sib tsoo log hardness txhais tau hais tias lub sib tsoo log abrasive nplej tsis yooj yim rau poob. Sib tsoo log hardness thiab abrasive hardness yog ob lub ntsiab lus sib txawv. Tib lub abrasive tuaj yeem ua rau hauv kev sib tsoo lub log ntawm qhov sib txawv hardness, uas feem ntau yog nyob ntawm cov khoom thiab ntau npaum li cas ntawm cov ntawv khi thiab cov txheej txheem ntawm kev sib tsoo. Qhov sib txawv tseem ceeb ntawm kev sib tsoo thiab txiav yog tias lub log sib tsoo muaj qhov ua haujlwm "tus kheej sib tsoo". Xaiv lub hardness ntawm lub sib tsoo log yog tiag tiag xaiv tus kheej-sib tsoo ntawm lub sib tsoo log. Nws cia siab tias cov abrasive yuav tsis poob los yog ua npub ntxov ntxov.
Lub hauv paus ntsiab lus dav dav rau xaiv qhov hardness ntawm lubdawb aluminium oxide sib tsoo logthiabxim av aluminium oxide sib tsoo logyog: thaum ua cov hlau mos, txhawm rau tiv thaiv cov abrasive los ntawm kev poob ntxov ntxov, lub log nyuaj yog xaiv. Thaum ua cov hlau tawv tawv, txhawm rau ua kom cov pob zeb nto abrasive poob tawm hauv lub sijhawm thiab nthuav tawm cov nplej tshiab nrog cov npoo ntse (xws li cov nplej zom nws tus kheej), xaiv cov khoom sib tsoo mos. Cov qub yog vim thaum sib tsoo cov ntaub ntawv mos, ua hauj lwm abrasive ntawm dawb aluminium oxide sib tsoo log thiab xim av aluminium oxide sib tsoo wheelwears maj mam thiab tsis tas yuav poob tawm ntxov; qhov tom kawg yog vim tias thaum sib tsoo cov ntaub ntawv nyuaj, kev ua hauj lwm abrasive ntawm dawb aluminium oxide sib tsoo log thiab xim av aluminium oxide sib tsoo log hnav sai dua thiab yuav tsum tau hloov kho sai. Nyob rau hauv kev sib tsoo precision, thiaj li yuav xyuas kom meej sib tsoo raug thiab roughness, ib tug me ntsis nyuaj dawb aluminium oxide sib tsoo log thiab xim av aluminium oxide sib tsoo log yuav tsum tau xaiv. Cov khoom siv ua haujlwm muaj cov thermal conductivity tsis zoo thiab ua rau kub hnyiab thiab tawg (xws li kev sib tsoo carbide, thiab lwm yam), cov xim dawb aluminium oxide sib tsoo log thiab xim av aluminium oxide sib tsoo log yuav tsum mos.
