1. Application examples
With a carbon content of more than 1%, this material is very well suited for feeler gauge tapes and shims, as well as for highly stressed springs that are not subject to corrosion requirements.

Other areas of application: Wear strips, pressure blades, valves in shock absorbers

In DIN EN 10 132-4, 1.1274 is approved as a material for springs. Compared to the materials 1.1231 (C67S), 1.1248 (C75S) and 1.1269 (C85S), which have a lower carbon content, the material 1.1274 is also suitable for high mechanical loads and has a high fatigue strength. It is the only carbon steel used for shock absorber valves and reed valves.

If there is a risk of corrosion and the highest demands on the mechanical load, we recommend the material 1.4031Mo, which is available in thicknesses of 0.10 to 2.0 mm.

2. Material codes
German Norm: 1.1274, C100S+QT (former Ck101)
AISI: 1095
ASTM: G 10950
Engl. Norm: 95 (B.S. 5770 Part 1)
Franz. Norm: XC 100
Japanese Norm: SK 4-CSP (Norm G 4802)

3. Alloy Composition *
C: 0,95-1,05%
Si: 0,15-0,35%
Mn: 0,30-0,60
P: max. 0,025%
S: max. 0,025%
Cr: max. 0,40%
Ni: max. 0,40%
Mo: max. 0,10%

* the exact composition of each batch can be documented by a material certificate 2.2 or 3.1 according to DIN EN 10 204.

4. Delivery condition
Condition: hardened and tempered (martensitic condition)
Surface: white polished, please ask for roughness values
flatness: mostly P2 = 0,3% of the strip width
Ultimate tensile strength:
see table (depending on the thicknesses from 1600-1800 to 2000-2200 N/mm²)
Further mechanical data: see chapter 7 and 8.

5. Sizes
thicknesses: 0,02-3,0 mm
raw material width: depending on the thicknesses from 12,7 to 600 mm (see table) standard widths: 6 – 12,7 – 25 – 50 – 100 – 150 und 305mm (not in all thicknesses)

Edges: in widths 6 and 12.7 mm round edges in thicknesses from 0.25 to 2.0mm, all other sizes with cut edges

lengths: individual lengths from 5 to 10 000mm or as coil

In the thicknesses from 0.60 to 5.03 mm we have the hardened tool steel 1.2003 (75Cr1) on stock.

6. Tolerances
thickness tolerace: T3
width tolerance: B2
straightness: normal
Flatness: P3 = 0,2% of the strip width

7. Further mechanical data
Yield str. Rp0,2 : approx. 90 % of the tensile strength
Elongation A 80: no data available
Fatigue strength: high fatigue strength, suitable for shock absorber valves and flapper valves

If good tumbling is done, the following values can be achieved:
Reversed bending stress (Mean stress = 0):
620-680 MPa at a failure rate of 5 %.

Fluctuating bending stress (Minimum stress = 0):
520-580 MPa at a failure rate of 5 %

As the fatigue strength depends on different factors like the corrosive conditions and the edge treatment, no definitive endurance limit values can be guaranteed.

Please ask if the requested batch meets the high demands for shock absorber valves or compressor valves.

The operation temperature should not exceed 200°C. Please remember that the modus of elasticity decreases at higher temperatures. For higher operation temperatures we suggest the stainless hardened steels like the alloys 1.4031Mo (up to 2.0 mm thickness) and 1.4034 (from 1.0 to approx. 10.0 mm thickness)

8. Physical properties
Density: 7,9 g/cm³
Thermal conductivity: 49 W/(m °C) bei 20 °C
Heat capacity: 460 J/(kg °C) medium value at 50 – 100 °C
Thermal expansion:
   10,5 x 10 -6 (between 30 - 100 °C)
   11,5 x 10 -6 (between 30 - 200 °C)
   12,5 x 10 -6 (between 30 - 300 °C)
Electric resistance: ca. 0,20 Ohm x mm²/m (for 1.1231= C67S hardened)

Modus of elasticity: 210 000 MPa bei 20 °C

Relative permeability µr: maximum 400 (for 1.1231= C67S hardened)

9. Blanking
We recommend a punch-to-die clearance of 4-10 % of the strip thickness.
The corner radius should be at least 0.25 mm and the punching die should be at least twice the strip thickness.
After blanking a stress relieving at a maximum temperature of 250°C for 30-60 minutes is suggested.
The pieces should then be tumbled to receive a good edge roundness.
Bei Stanzteilen ist ein Nachbehandeln durch Gleitschleifen zur Erzielung einer guten Dauerfestigkeit notwendig.

We suggest to produce the pieces by photo etching.

10. Laser cutting
As the material melts at the edge during laser cutting, a higher hardness and therefore a lower toughness at the cutting zone is possible. We suggest to produce critical pieces by water jet cutting.

11. Photo etching
This alloy is very easy to etch.

12. Bending
As this material is supplied in the hardened and tempered condition, the rolling direction is not important regarding the bending.

13. Flat grinding
The alloy 1.1274 is magnetisable and can be fixed by magnetic clamping devices of flat grinding machines.

14. Welding
Due to the high content of carbon the alloy 1.1274 should not be welded.

15. Corrosion resistance
The alloy 1.1274 is not corrosion resistant. We supply this alloy with a light oil film. If used at normal conditions this alloy needs to be painted or galvanized.