ASTM SAE AISI 1045 Carbon Steel Heat Treatment, Chemical Composition, Properties

SAE AISI 1045 Steel

ASTM SAE AISI 1045 steel is one of the commonly used medium carbon steels with an average carbon content of 0.45%, medium tensile properties, good strength, toughness and wear resistance. It can be treated by annealing, flame treatment or induction hardening.

C1045 is also known as 1045 cold rolled steel (cold worked), and 1045 hot rolled steel is known as 1045 HR.


AISI SAE 1045 material is widely used in industrial applications where higher wear resistance and strength are required, typical applications including: Light gears, shafts, axles, spindles, pins, guide rods, connecting rods, bolts, worms, crankshafts, machine components, etc.

Datasheet & Specification

The table below gives the AISI SAE ASTM 1045 steel data sheet including chemical composition, physical properties, mechanical properties, etc.

Chemical Composition

AISI ASTM 1045 Chemical Composition (%)
Steel Grade (UNS) C Mn P (≤) S (≤)
1045 (G10450) 0.43-0.50 0.60-0.90 0.040 0.050

Physical Properties

AISI SAE 1045 coefficients of linear thermal expansion
Value (10-6/K) Temperature (°C) Treatment
or condition
11.6 0-100 Annealed
12.3 0-200
13.1 0-300
13.7 0-400
14.2 0-500
14.7 0-600
15.1 0-700
Material 1045 thermal conductivity
Value (W/m·K) Temperature (°C) Treatment
or condition
50.8 100 Annealed
Material 1045 thermal conductivity
Value (W/m·K) Temperature (°C) Treatment
or condition
50.8 100 Annealed
Electrical Resistivity of AISI SAE 1045 Carbon Steel
Value (μΩ·m) Temperature (°C) Treatment
or condition
0.162 20 Annealed
0.223 100

Mechanical Properties

1045 material mechanical properties are listed in the following table including tensile strength, yield strength, elongation, reduction and hardness, etc.

1045 carbon steel mechanical properties (sizes ranging: 19-32 mm)
Steel (UNS) Tensile strength (Mpa) ≥ Yield strength (Mpa) ≥ Elongation in 50 mm, % ≥ Reduction in area, % ≥ Hardness (HB) Processing, condition or treatment
AISI SAE 1045 (G10450) 565 310 16 40 163 Hot rolled
625 530 12 35 179 Cold drawn
585 505 12 45 170 Annealed, cold drawn

1045 Steel Heat Treatment


1045 normalizing temperature range is 830-900 °C and the typical normalizing temperature is 860 °C.


The austenitizing temperature for SAE 1045 induction hardening carbon steel is 800-845 °C.

Full Annealing

The annealing temperature for AISI 1045 carbon steel is from 790-870 °C, cooling cycle from 790 to 650 °C at a rate of 28 °C/h in furnace, and can get the HBW hardness range from 156 to 217. (Suitable for forgings with a section thickness of up to 75 mm. For the section up to 25 mm thick, the temperature time is usually at least 1 hour; for each 25 mm thick increase, 0.5 h is added.)


The austenitizing heating at 845 °C, the quenching medium is water or brine, and the workpiece with wall thickness ≤6.35 mm is oil quenched, and the hardness should be no less than 55 HRC.


For the thickness of the weldment is ≤13mm, the preheating and interpass temperature is at least 150 °C under low hydrogen condition, other than low hydrogen, the temperature is minimum 177 °C, heat treatment is required after welding and the temperature range is 590-675 °C.

For the weldment thickness (t) 13<t≤100mm, the preheating and interpass temperature is ≥205 °C (under low hydrogen condition), ≥230 °C (except low hydrogen), and the postweld heat treatment temperature is 590-675 °C.

1045 Steel Equivalent Grade

ASTM AISI SAE 1045 carbon steel equivalent to European EN (Germany DIN EN, British BSI, French NF…), Chinese GB and Japanese JIS standard.

AISI 1045 equivalent
US Germany China Japan ISO
Standard Grade (UNS) Standard Steel name (Steel number) Standard Grade Standard Grade Standard Grade
1045 (G10450) EN 10083-2 C45 (1.0503) GB/T 699 45 Steel JIS G  4051 S45C

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