Carbon Steel

C45 · 1.0503

Also known as 1045 / S45C / Ck45

Medium-carbon engineering steel for general machine parts.

C45 (material 1.0503, equivalent to AISI 1045) is an unalloyed medium-carbon engineering steel with a good balance of strength, wear resistance and machinability. Supplied hot-rolled, normalised or cold-drawn (bright), it is one of the most common general-purpose grades for shafts, bolts and machine components.

International equivalents.

The same steel by country and standard — near matches; mill certificate governs.

C45 (1.0503) · EN 1045 · AISI / SAE S45C · JIS 45 · GB

Chemical composition.

Indicative, % by weight per EN 10083-2. Mill certificate governs.

Element%
C 0.42 – 0.50
Si ≤ 0.40
Mn 0.50 – 0.80
Cr ≤ 0.40
Mo ≤ 0.10
Ni ≤ 0.40
P ≤ 0.045
S ≤ 0.045

Mechanical properties.

Indicative; depends on dimension and heat treatment.

Tensile strength (Rm)
580 – 700 MPa (normalised)
Yield strength (Re)
≥ 305 MPa
Elongation (A)
≥ 16 %
Hardness (annealed)
≤ 207 HB

Available forms.

Round bar Flat bar Square bar Bright / cold-drawn bar

Size range: Ø 6 – 250 mm

Typical applications.

  • Shafts & axles
  • Bolts & fasteners
  • Gears
  • General machine parts
Standards: EN 10083-2EN 10277-2

FAQ.

What is C45?

C45 (material 1.0503, equivalent to AISI 1045) is an unalloyed medium-carbon engineering steel with a good balance of strength, wear resistance and machinability. Supplied hot-rolled, normalised or cold-drawn (bright), it is one of the most common general-purpose grades for shafts, bolts and machine components.

Is C45 the same as 1045?

Yes — C45 is the European (EN) designation, while 1045, S45C, Ck45 are the matching names used in other countries and standards (for example AISI/SAE in the USA, JIS in Japan, GB in China, former DIN in Germany). They are near equivalents and may differ slightly in chemistry; the mill certificate governs the exact specification.

What are the international equivalents of C45?

C45 corresponds to C45 (1.0503) (EN), 1045 (AISI / SAE), S45C (JIS), 45 (GB). Equivalents are nearest matches by country/standard; the mill certificate governs the exact specification.

In which forms is C45 available?

C45 is supplied as Round bar, Flat bar, Square bar, Bright / cold-drawn bar, in Ø 6 – 250 mm.

What is C45 used for?

Typical applications include Shafts & axles, Bolts & fasteners, Gears, General machine parts.