1.1191 Steel

aisi 1045

  • 1.1191steel belongs to Germany steel grade standard DIN 17200 and EN 10083. Which is carbon steel standard specification for machinery structural application.
  • 1.1191 steelis widely used in machinery manufacturing, 1.1191 medium carbon steel have good mechanical properties.
  • 1.1191 steelis defined as medium carbon steel, 1.1191 steel has 0.43%-0.5% Carbon.
  • 1.1191 steeloffers good weldability, good machinability, high strength and impact properties.
  • 1.1191 steelis low in hardenability, because of lack of suitable alloying elements.
  • 1.1191 steelcan obtain surface hardnesses 54-60HRC after flame or induction hardening.
  • 1.1191 steelis generally supplied in the black hot forged or normalized condition,and has a tensile strength of 570 -700 MPa with surface hardness170-210HB.

    1.Supply Form & Size & Tolerance

Supply Form Size(mm) Process Tolerance
Round Φ6-Φ100 Cold Drawn Bright/Black Best H11
Φ16-Φ350 Hot Rolled Black -0/+1mm
Peeled/ground Best H11
Φ90-Φ1000 Hot Forged Black -0/+5mm
Rough Turned -0/+3mm
Flat/Square/Block Thickness :120-800 Hot Forged Black -0/+8mm
Width:120-1500 Rough Machined -0/+3mm

Remark:Tolerance can be customized as per requests

2.Chemical Composition

Standard Grade C Si Mn P S Cr
ASTM A29 1045 0.43-0.50  - 0.60-0.90 ≤0.04 ≤0.05  -
EN 10083-2 C45 0.42-0.50 ≤0.04 0.50-0.90 ≤0.03 ≤0.035 ≤0.4
JIS G4051 S45C 0.42-0.48 0.15-0.35 0.60-0.90 ≤0.03 ≤0.035  -

3.Physical Property

Density, g/cm3 7.87
Melting point °C 1495
Modulus of Elasticity, psi 29 x 10^6
Coefficient of Thermal Expansion, 68-212˚F, /˚F 6.39 x 10^-6
Thermal Conductivity, Btu/ft hr ˚F 30
Specific Heat, Btu/lb ˚F 0.116
Electrical Resistivity, Microhm-in 6.42
  1. Mechanical Property

Section Size mm ≤ 16 17 – 40 41 – 100
Tensile Strength Mpa 700-850 6500-800 630-780
Yield Strength Mpa ≥ 500 ≥430 ≥ 370
Elongation in 50mm % ≥ 14 ≥ 16 ≥ 17
Impact Charpy J ≥ 30 ≥ 30 ≥ 30
Hardness HB 210-245 195-235 185-230

Remark:Water Quench at 820 oC -850 oC or oil quench at 830 °C-860°C and Tempered Between 540 °C – 680 °C


Heat 1.1191 steel with two steps,first heat the temperature to 750 oC – 800 oC ,hold for suitable time,then heat the temperature up to 1100 oC – 1200 oC,hold enough time for the steel to be thoroughly heated.Minimum forging temperature 850°C,so don’t forge below it.1.1191 steel should be cooled as slowly as possible in still air or in sand after forged.


Normalizing is used to refine the structure of forgings that might have cooled non-uniformly after forged,and considered as a conditioning treatment before final heat treatment.Normalizing temperature for 1.1191 steel should be carried out between 870℃-920℃. hold suitable time for the steel to be thoroughly heated to  complete the ferrite to austenite transformation.Soak for 10 – 15 minutes,then cool in still air.


Annealing  is considered as a treatment  suitable for machining.1.1191 steel should be carried our at a nominal temperature of 800℃-850℃,hold suitable time for the steel to be thoroughly heated, then furnace cooling.


1.1191 steel may be hardened to increase surface hardness and strength.It is usually heated to temperature  820oC – 860oC,hold suitable time for the steel to be  heated uniformly,soak for 10 -15 minutes per 25mm of section, and quench in water or oil.Tempering should be followed  immediately after quenched.


Tempering will be carried out to optimize the property after quench.1.1191 steel is usually heated  to 400oC – 650oC as required, hold until temperature is uniform throughout the section, soak for 1 hour per 25mm of section, and cool in still air.


Compared with 1.0402,1.1191 steel has low alloy,but can be flamed or induction hardening to obtain high strength,and is widely used in many industries which require more strength,wear resistance,

Typical applications includes Axles,Bolts, Connecting Rods, Hydraulic Clamps ,Rams, Pins , Rolls, Studs, Shafts, Spindles, Sockets, Light gears etc.