Blacksmithing
and Cutlery
by Gérard HEUTTE
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Steel standard classification
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Here are some information to help with
standardized (finally more or less standardized) steels designations.
European Numerical designation
This designation refers to standard NF EN 10027-2.
Each matter is coded in numerical form:
| X.YYZZ |
X: Family of matter (1 for steel) |
| YY: Number of the group |
| ZZ: Sequence number in the group |
Obviously, with this system, not question of intuition
or deduction. You know or you do not know!
For example, steel 1.1620 is XC70 (1070).
This designation is practically unused except in industry and almost
never in cutlery... Guess why!
French Symbolic Designation system (by use)
This designation refers to standard NF EN 10027-1.
This simple system is based on the use of steel. Well
known E24 is a mechanical construction steel with an elastic limit (E)
of 24 MPa.
This system is never used in cutlery, because it is dedicated
to steels which cannot be hardened!
European Symbolic Designation system (by physicochemical
constitution)
This designation refers to standard NF EN 10027-1.
This system is based on the chemical composition of steels.
The first information relates to the Carbon rate. Then,
all depends on the presence of elements of alloy and their content.
Non-allied steels
A steel is called non-allied when alloy elements are
less than a threshold. The threshold is given in
the table of the alloy elements at the end of this page.
Thus a steel containing 0.2 % of Silicon will be
considered as non-allied.
Such a steel is noted by:
- A prefix "C" or "XC"
- Centesimal carbon content.
For example, a XC65 is a non-allied steel with 0.65% of Carbon.
Slightly allied steels
A steel is known as slightly allied when one or
more its elements exceeds the threshold while remaining lower than 5%.
Such a steel is noted by:
- Centesimal carbon content.
- The list of the alloy elements (higher than the threshold),
indicated by their chemical or metallurgical symbol and classified by
decreasing rate.
- Numbers giving the values of the contents affected of a
coefficient. These coefficients are given in the same order as
the list of the elements. If an element does not have
associated content, one knows simply that it has a content higher than
the threshold, without more precision.
For example, the 90MCV8 is a low alloy steel with 0.90% of
Carbon, 2 % (i.e. 8 the number / 4 the coefficient) of Manganese,
Chromium (> 0.30%) and Vanadium (> 0.10%).
Strongly allied steels
A steel is known as strongly allied when one or
more its elements is present at 5% or more.
Such a steel is noted by:
- A Prefix "Z"
- Centesimal carbon content.
- The list of the alloy elements (higher than the threshold),
indicated by their chemical or metallurgical symbol and classified by
decreasing content.
- Numbers directly giving (without coefficient) the rate of
the contents assigned to each element in %.
If an element does not have associated content, one
knows simply that it has a content higher than the threshold, without
more precision.
For example, Z100CDV5-1 is a high alloy steel with Carbon 1%,
Chromium 5%, Molybdenum 1% and Vanadium (> 0.10%).
Alloy elements
Here is a list of the alloy elements usually included in steels.
The table below gives for each one of them:
- Name
- Chemical Symbol
- Metallurgical symbol
- Coefficient (used for the notation of slightly allied steels)
- Threshold (limit below which the element is not
included in description).
| Element |
Chemical
Symbol |
Metallurgical
Symbol |
Coefficient |
Threshold (%) |
| Chromium |
Cr |
C |
4 |
0.30 |
| Manganese |
Mn |
M |
4 |
1.65 |
| Molybden |
Mo |
D |
10 |
0.08 |
| Nickel |
Ni |
N |
4 |
0.30 |
| Silicon |
If |
S |
4 |
0.50 |
| Tungsten |
W |
W |
4 |
0.10 |
| Vanadium |
V |
V |
10 |
0.10 |
"Homemade" Designation
Sometimes steel industries have
(often) their own denomination for their steels. There is no
precise system. However you can find correspondences in their
catalogues or Web sites.
Thus at Eurotechni, the XC75 is called "DNH7"...
The "15N20", more and more used to make Damascus is 75Ni8.
American designation
To find itself there in the literature in English (often coming
from USA), it is necessary to speak about the US designations managed by two
organizations: SAE and AISI. These references are:
(1) Alphanumeric codes which do not have a link with the chemical
composition of these steels, but rather on the
use of steel. For example, you will find of D2, W1.
(2) Numeric digital codes whose first figure indicates
one or more alloy elements. For example, you can find 1080 or 52100.
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