Symbol and units of measure

FATT Transition temperature at which the inter-granular failure area is 50% of the original area after failure of various Charpy V-notch specimens.  
Various temperatures may be used from – 180° C (liquid nitrogen) up to + 150°C and above
                     
E / G E = Modulus of elasticity longitudinal   G = Modulus of elasticity tangential
                     
Em Failure energy with pendulum hammers test for impact strength, types:  Kv  –  KCU –  DVM –  Mesnager – KW
                     
N Force:   Newton                 
                     
J Energy: Joule                 
                     
Ksi Stretch: thousands of pounds– force per square inch 
                     
lbf Force – pound                 
                     
Rm – R – TS Tensile strength calculated with proportional tensile specimens, expressed in N/mm²
                     
Rp 0.2  YS 0.2 Yield strength normally taken at 0.2% and in some cases at 0.02%. Value obtained from tensile test, expressed in N/mm²  / Mpa
                     
Re – ReH Total strength, read directly on the gauge of the tensile testing equipment as it corresponds to a stop in the increase in load   
                     
E% – A% Percentage elongation after fracture. Value obtained from tensile test
A% = [ (Lu – Lo) : Lo ] x 100   
Lu = final gauge length after fracture  
Lo = original gauge length 
Z% – C% Reduction of area after failure. Value obtained from tensile test
C% – Z%  = [ (So – Su) : So ] x 100  
So = original cross-sectional area of the parallel length
Su = minimum cross-sectional area after fracture
                     
Kcu Impact strength with U notch, proportional specimens tested with pendulum hammers with energy measurement expressed in J     
                     
Kv Impact strength with V notch
                     
HB
10/3000
Brinell hardness EN 10003, calculated on the surface of the material. It is useful for knowing the approximate tensile strength of the material 
HB 10/3000 10 = ball dia. in mm, 3000 = pressure in kg
                     
HRC
Scale 150 
Rockwell hardness “C” EN 10109, normally used on materials with a tensile strength of from 760 N/mm²  to 2420 N/mm²   
                     
HV Vickers hardness, normally used on materials with a tensile strength of from 1320 N/mm² to above 2500 N/mm²  
                     
Most commonly used terms
                     
  USA – UK Germany   Italy   France
R – TS Tensile strength Zugfestigkeit    Rottura   Resistance
Rp – YS Yield strength Streckgrenze    Snervamento   Limite d’elasticité 
A% Elongation  Dehnung    Allungamento   Allongement 
C% Reduction  Einschnurung    Contrazione   Striction 
Kv, Kcu
etc
Impact strength Kerbschlagzahigkeit    Resilienza   Resilience 
HB HV HRC Hardness test Härte    Durezza
    
  Dureté