Structural steel
C45N / 1.0503 normalised carbon steel
C45N is C45 supplied normalised. The W.Nr. is still 1.0503. +N gives a more uniform ferrite-pearlite structure than hot-rolled bar – that is what the drawing means when it writes C45N and not just C45. Same chemistry as C45; the difference is the condition. 42CrMo4 when the core has to hold in a coarser cross-section.
- Designation
- C45N
- W.Nr.
- 1.0503
- Condition
- +N (normalised)
- Standard
- EN 10083-2
- EN designation
- C45+N
- Group
- Non-alloy structural steel
- Typical forms
- round bar, flat bar, square bar
Typical applications
- Shafts and machine parts with predictable machining without normalising yourselves
- Shafts, bolts and machine parts in small cross-sections
- Parts where the drawing requires +N
Delivery conditions
- +N (normalised)
Designations
- W.Nr.
- 1.0503
- EN standard
- C45+N
- DIN
- C45N
- AISI/SAE
- 1045
- UNS
- G10450
- JIS
- S45C
- Group
- Non-alloy structural steel
Chemical composition
Typical range to EN 10083-2 (cast analysis)
| Element | Range |
|---|---|
| C | 0.42–0.50 % |
| Si | max. 0.40 % |
| Mn | 0.50–0.80 % |
| P | max. 0.045 % |
| S | max. 0.045 % |
| Cr + Mo + Ni | max. 0.63 % (residual alloying) |
C45N is the same chemistry – +N is a condition, not a different analysis. C45E (1.1191) has tighter phosphorus and sulphur.
What C45N is
C45N is C45 supplied normalised. The W.Nr. is still 1.0503, and the standard is EN 10083-2. +N gives a more uniform ferrite-pearlite structure than hot-rolled bar. It is a non-alloy carbon steel: the carbon gives hardness after hardening, and through-hardening is limited to small cross-sections. It is not S355, and it is not 42CrMo4.
Typical applications
Shafts and machine parts with predictable machining and uniform hardness without normalising yourselves. Shafts, bolts and machine parts in small cross-sections, where C45N is hardened or used in +N.
- Shafts and machine parts that have to machine predictably
- Bolts and machine parts in small cross-sections
- Parts where the drawing writes C45N and not just C45
Delivery condition and dimensions
The condition is +N (normalised) – the condition the mill has supplied. We source C45N from European partners as round bar, flat bar and square bar, cut to your dimensions and ship the certificate with it. From a single cut piece to larger batches – no minimum charge, so you do not have to buy a full commercial length to get what you need. Send dimensions, quantity and form, and we confirm what can be cut. Stock status is confirmed on enquiry.
Machining and welding
Pieces are cut to length in C45N. +N is the condition the mill has supplied – cutting does not change it. C45N is chosen when the part has to machine predictably with uniform hardness. Through-hardening only reaches in small cross-sections: 42CrMo4 when the diameter grows. S355 when the part has to be welded.
Certificates and documentation
C45N can be supplied with a material certificate to EN 10204, depending on the producer, the dimension and the specified requirements for the delivery. The condition is what the certificate has to carry on C45N: as-rolled, +N and +QT are not the same product, and if a hardness or strength has to be documented in the delivered dimension, the requirement belongs on the enquiry. EN 10204 3.1 can be supplied on a wide range of our materials. 3.1 is included at no charge.
C45 or C45N
Same chemistry. The difference is the delivery condition. C45N when the part has to machine predictably with uniform hardness without normalising yourselves. C45 when the drawing does not require +N and the price has to stay down. C45E (1.1191) has tighter phosphorus and sulphur. +N, +QT and as-rolled bar are covered together in the guide on how bar is supplied.
- C45 / 1.0503 – same chemistry, no +N requirement
- C45N / 1.0503 – C45 in the normalised condition (+N)
- C45E / 1.1191 – tighter phosphorus and sulphur
- 42CrMo4 / 1.7225 – when the core has to hold in a coarser cross-section
Dimension programme
| Form | Range | Note |
|---|---|---|
| Round bar | Ø20–200 mm | Same chemistry in +N. Still not S355. |
| Flat bar | Cut to order | State cross-section. |
| Square bar | Cut to order | State side length. |
Parts of the range are held by European partners; other dimensions can be sourced. The range is not a current stock status in every diameter — stock is confirmed on enquiry.
Frequently asked questions
- What is the difference between C45 and C45N?
- Same chemistry and the same W.Nr. 1.0503. The difference is the delivery condition: C45N is supplied normalised (+N), which gives a more uniform ferrite-pearlite structure than hot-rolled bar.
- Does cutting change the +N condition?
- No. +N is the condition the mill has supplied – cutting does not change it.
- When should I choose 42CrMo4 instead of C45N?
- When the core has to hold in a coarser cross-section. Through-hardening in C45N only reaches in small cross-sections.
- Do you supply C45N cut to length with a certificate?
- Yes. Send dimensions, quantity and form, and we confirm what can be cut. 3.1 is included at no charge.
Read more
Looking for C45N / 1.0503?
Send dimensions, quantity and form, and we confirm what can be cut. We cut to length and ship with EN 10204/3.1. Stock status is confirmed on enquiry.