Carbon & alloy steel · ASTM A29

AISI 1045 normalized

Also known as: 1045, AISI 1045

Full datasheet

Overview

US designation for medium-carbon 1045 steel in normalized condition — interchangeable with EN C45 for many shaft designs.

Typical supply: Cold- and hot-finished bars

Mechanical Properties

Young's modulus E210 GPa
Shear modulus G80.8 GPa
Yield / proof Re310 MPa
Ultimate Rm565 MPa
Poisson's ratio ν0.3
Endurance limit Se260 MPa
Hardness170 HB
Shear strength339 MPa
Bearing strength620 MPa

Thermal Properties

Thermal expansion α12 µm/(m·K)

For temperature derating, open Temperature Properties.

Physical Properties

Density ρ8e+3 kg/m³
Specific strength Sy/ρ3.95e+4 Pa·m³/kg
Specific stiffness E/ρ2.68e+7 Pa·m³/kg

Typical supply: Cold- and hot-finished bars

Density typically ~7800–7850 kg/m³. Bar and forging forms dominate machine design.

Applications

  • Shafts and spindles
  • Bolts and studs (selected)
  • Gears and sprockets
  • Hydraulic components

Advantages

  • Higher strength and hardenability than mild structural steel
  • Responds well to quench and temper for tailored properties
  • Good fatigue performance when heat-treated correctly

Limitations

  • Often needs heat treatment to reach published strengths
  • Weldability may require preheat / post-weld heat treatment
  • Corrosion resistance similar to carbon steel unless coated

Standards

  • ASTM A29 — General requirements for steel bars
  • SAE J403 — Chemical compositions of SAE carbon steels

Equivalent Materials

Compare with these grades →

Electrical Properties

Resistivity1.600e-7 Ω·m

Chemical Composition

ElementMin wt%Max wt%Typical wt%
C0.430.50.45
Mn0.60.90.75
P—0.04—
S—0.05—

Typical / limit values for reference selection only — verify against mill certs for certified work.

Machinability

Approximately 55–60% of AISI 1212 machinability index.

Cost

Commodity carbon bar pricing in North America.

Corrosion

Requires coating or oil for corrosion protection.

  • Oil-lubricated machineryfair
  • Outdoor uncoatedpoor

For allowance / life screening, open Corrosion Allowance.