MATERIAL TO PROCESS

GLOSSARY

• Hardness : Characterizes the resistance of a material to penetration. there are 3 hardness measurement scales for steels : Brinel ( HB), Rockwel (HRc Hra), Vickers ( HV) depending on the shape of the testing tool.
• Elasticity : aptitude of a material to find its initial form after having undergone an effort. The rated yield strees Re, measured in N / mm2, indicates the acceptable maximum effort before permanent deformation
• Ductility : aptitude of a material to accept permanent deformation. The A% rating expresses the lengthening capacity as a percentage
• Resilience : rupture resistance characteritic under the effect of shocks
• Tensile strength : Is the maximum load which the material can withstand before breaking; it is usually expressed in N / mm2 or in Kg / mm2.

Erroneous ideas :
"Whatevermore can,less can" or, in other words " a tap for hard steel will work well in a normal steel" : this is false and dangerous because a tap for hard steel has very little "cut", thus it will require an exaggerate force while working and will snap off.
"Stainless steels are hard" : Generally not, except for superalloys, most of the current stainless steels are rather ductile and require a tool with a lot of " cut".