Scratch hardness: Feem ntau yog siv los sib piv cov hardness ntawm cov minerals sib txawv. Txoj kev siv tus pas nrig nrog ib qho nyuaj kawg thiab lwm qhov kawg kom khawb cov khoom raug kuaj. Lub hardness ntawm cov khoom yog txiav txim los ntawm qhov chaw ntawm khawb. Hais lus zoo, ib qho khoom tawv ua rau khawb ntev dua, thaum cov khoom muag muag ua rau luv luv.
Indentation hardness: Feem ntau yog siv rau cov khoom siv hlau. Cov txheej txheem yuav tsum nias lub indenter teev rau hauv cov khoom nyob rau hauv ib tug tej yam load. Lub hardness ntawm cov khoom yog muab piv los ntawm qhov loj ntawm lub zos yas deformation ntawm qhov chaw. Vim qhov sib txawv ntawm qhov indenter, load, thiab lub sijhawm thauj khoom, muaj ntau hom indentation hardness, feem ntau Brinell hardness, Rockwell hardness, Vickers hardness, thiab microhardness.
Rebound hardness: Feem ntau yog siv rau cov khoom siv hlau. Cov txheej txheem cuam tshuam nrog kev tso me me rauj tshwj xeeb los ntawm qhov siab los cuam tshuam cov qauv ntawm cov khoom raug kuaj. Lub hardness ntawm cov khoom yog txiav txim los ntawm tus nqi ntawm strain zog khaws cia (thiab tom qab tso tawm) los ntawm cov qauv thaum lub sij hawm muaj kev cuam tshuam (ntsuas los ntawm lub rebound qhov siab ntawm rauj).
