Alleima® 7C27 is a martensitic stainless chromium steel characterized by very good hardening properties and very good cold formability. After hardening and tempering, the grade has very good corrosion resistance and toughness.
Alleima® 7C27 is characterized by:
- Soft delivery condition
- Very good hardening properties
- Very good cold formability
- High corrosion resistance after hardening and tempering
Standards
- ASTM: 420
- AWS: ER 420
- EN Number: 1.4028 Mod./1.4031 Mod.
- W.Nr.: 1.4007
- DIN: X35Cr14
- SS: 2304
- AFNOR: Z 30C13(13H)
Product standards
- ASTM F899
- ISO 16061
Applications
Alleima® 7C27 can be used for surgical suture needles, dental burrs, drills and tartar removers.
Chemical composition (nominal) %
| C | Si | Mn | P | S | Cr |
|---|---|---|---|---|---|
| 0.32 | 0.2 | 0.3 | ≤0.025 | ≤0.010 | 13.5 |
Forms of supply
The wire is supplied coated with an anti-corrosion oil that should not be removed in storage. In cases where the first work operation is a straightening-cutting operation, the oil acts as an excellent lubricant and prevents scratching of the wire surface.
After the oil is removed, the wire should not be stored on premises with a high moisture content, since the material can be subject to corrosion in the unhardened state.
The wire surface is bright in diameters 0.10 - 2.50 mm (0.004 - 0.098 in.). Larger wire diameters can be manufactured on request.
| Dimension | Spool no | Wire weight | ||
|---|---|---|---|---|
| mm | in. | kg | lb | |
| 0.285 - 1,6 | 0.011 - 0.063 | 23 | max 16 | max 35 |
| Dimension, mm | Inside diameter of coil, mm | Wire weight, kg |
|---|---|---|
| 0.50 - 0.80 | 250 | max 16 |
| >0.80 - 1.60 | 300 | max 20 |
| >1.60 - 1.80 | 300 | max 20 |
| >1.80 - 2.50 | 450 | approx. 60 |
| Dimension, in. | Inside diameter of coil, in. | Wire weight, lb |
|---|---|---|
| 0.02- 0.031 | 9.8 | max 35 |
| >0.031 - 0.063 | 11.8 | max 44 |
| >0.063- 0.071 | 11.8 | max 44 |
| >0.071 - 0.098 | 17.7 | approx. 132 |
In exceptional cases, spools or coils of lower weight than given in the above tables can be included in a delivery.
Tolerances
The diameter tolerance is normally D3. The wire can also be supplied with tolerance grades D1 and D2.
| Dimension, mm | Diameter tolerance, mm +/- | ||
|---|---|---|---|
| D1 | D2 | D3 | |
| 0.10 - 0.125 | 0.007 | 0.004 | 0.002 |
| >0.125 - 0.25 | 0.009 | 0.005 | 0.003 |
| >0.25 - 0.50 | 0.011 | 0.007 | 0.004 |
| >0.50 - 1.00 | 0.014 | 0.009 | 0.005 |
| >1.00 - 1.60 | 0.018 | 0.011 | 0.006 |
| >1.60 - 2.50 | 0.023 | 0.014 | 0.008 |
| Dimension, in. | Diameter tolerance, in. | ||
|---|---|---|---|
| D1 | D2 | D3 | |
| 0.004 - 0.005 | 0.00028 | 0.00016 | 0.00008 |
| >0.005 - 0.010 | 0.00035 | 0.00020 | 0.00012 |
| >0.010 - 0.020 | 0.00043 | 0.00028 | 0.00016 |
| >0.020 - 0.039 | 0.00055 | 0.00035 | 0.00020 |
| >0.039 - 0.063 | 0.00071 | 0.00043 | 0.00024 |
| >0.063 - 0.098 | 0.00091 | 0.00055 | 0.00032 |
Mechanical properties
The wire is supplied in tensile strengths within the range shown in the table below. The smaller the diameter, the higher the tensile strength within the stipulated range.
| Tensile strength, Rm | MPa (ksi) |
|---|---|
| 730 - 900 (106 - 131) |
Other tensile strengths can be supplied on request.
Physical properties
Density: 7.7 g/cm3, 0.28 lb/in3
Heat treatment
Soft-annealing
When required, soft-annealing should be conducted for a period of one hour at a temperature of 650-680°C (1200-1250oF).
| Temperature, oC (oF) | 1050 - 1080 (1920 - 1975) |
| Holding time, minutes | 5 - 6 |
Quenching in oil or in protective gas.
To prevent oxidation, hardening should be carried out in a protective gas atmosphere using nitrogen or argon, alternatively in vacuum. The use of other gases can cause brittleness, blanks sticking together etc.
| Tempering time, minutes | 30 |
| Temperature , oC (oF) | 250-300 (480-570) Depending on the final hardness and ductility required |
Disclaimer: Alleima is not providing any products or services that are intended or may be construed to be recommending or otherwise advising on, in any manner, the design, suitability, appropriateness or effectiveness, from a medical/biological/safety perspective, of any medical material, instrument and/or medical device.