EN24T Steel

EN24T also known as 817m40 is normally supplied in the ‘T’ condition with a tensile strength in the range 850/1000 N/mm2. EN24T steel is a very popular grade of through-hardening alloy steel, this is down to its excellent machinability in the “T” condition.

EN24T is used in components such as gears, shafts, studs and bolts, its hardness is in the range 248/302 HB. EN24T can be further surface-hardened to create components with enhanced wear resistance by induction or nitriding processing.

EN24T steel is a high tensile alloy that offers excellent wear resistance and also high strength. EN24T is used in components that are subject to high stress and that have a large cross section. This can include automotive, aviation and general engineering applications. This includes propeller or gear shafts, connecting rods, aircraft landing gear components.

Typical chemical composition of En24T

C

SI

MN

S

P

Cr

Mo

Ni

0.36/ 0.44 0.10/ 0.35 0.45/ 0.70 0.040 max 0.035 max 1.00/ 1.40 0.20/ 0.35 1.30/ 1.70

EN24T Steel Mechanical Properties

Size
mm
Tensile
Strength
N/mm²
Yield
Stress
N/mm²
Elongation Impact
Izod J
Impact
KCV J
Hardness
HB
63 to 150 850-1000 680 Min 13% 54 50 248/302
150 to 250 850-1000 654 Min 13% 40 35 248/302

 

Hardening EN24: Heat uniformly to 823/850°C until heated through. Quench in oil.

Tempering:  Heat uniformly and thoroughly at the chosen tempering temperature, up to 660°C and hold at heat for two hours per inch (25 mm) of  total thickness.
Tempering between 250-375°C in not recommended as this can seriously reduce the steels impact value.

Stress Relieving: Heat slowly to 650-670°C, soak well. Cool the EN24 tool in a furnace or in air.