Exera® 11R51 / 11R51 HV medical wire Wire

Datasheet updated

2022-05-10 07:47
(supersedes all previous editions)

Exera® 11R51 and Exera® 11R51 HV (vacuum remelted) are austenitic stainless steels alloyed with molybdenum that are characterized by high tensile strength and high resistance to corrosion, fatigue and relaxation.

Vacuum-remelted Exera® 11R51 HV offers higher cleanliness compared to Exera® 11R51, which is usually required for medical applications.

Compared with the standard grade Exera® 12R10 medical wire, Exera® 11R51 and Exera® 11R51 HV offer:

  • Higher tensile strength and tempering effect
  • Higher relaxation resistance, especially at elevated temperatures
  • Higher fatigue strength
  • Better corrosion resistance, through the addition of molybdenum

Service temperature: -200 to 300°C (-330 to 570°F)
These grades are used for applications such as root canal files, reamers, broaches, surgical suture needles, braces, and acupuncture needles.

Standards

  • UNS: S30151
  • ISO: X9 CrNi 18-8
  • EN Number: 1.4310
  • EN Name: X10CrNi18-8

Product standards

EN 10270-3
ISO 6931-1
ASTM F 899, A 313/A 313M

Applications

Exera® 11R51 medical wire is used in applications such as root canal files, reamers, broaches, surgical suture needles, braces, and acupuncture needles.

Chemical composition (nominal) %

C Si Mn P S Cr Ni Mo
0.08 1.5 1.8 ≤0.025 ≤0.010 17 7.5 0.7

Forms of supply

Wire is delivered in a number of different forms to suit customers' requirements:

  • In coils with weights up to 150 kg
  • On various types of spools with wire weights up to 500 kg
  • In straightened lengths up to 4 m

Click on the following items for detailed information about surfaces finishes, delivery forms spools and coils, diameter tolerances and ovality.

Surface finishes and size range
Surface finishSize range, mm
Coated 0.20- 8.50
Nicoat A (nickel coating) 0.22- 2.50
Bright 0.11- 0.80
Nicoat P (nickel coating + bright) 0.40- 6.00
Mechanically polished 0.40 - 6.00

Mechanical properties

Mechanical properties in the `as delivered´ condition

Tensile strength and proof strength, MPa (ksi)

Wire diameter NominalNominal
Rm1Rp0.2
mmin.MPaksiMPaksi
0.15 – 0.20 0.0059 - 0.0079 2530 367 2150 312
>0.20 – 0.30 >0.0079 - 0.012 2470 358 2100 305
>0.30 – 0.40 >0.012 - 0.016 2420 351 2060 299
>0.40 – 0.50 >0.016 - 0.020 2365 343 2010 292
>0.50 – 0.65 >0.020 - 0.026 2310 335 1960 284
>0.65 – 0.80 >0.026 - 0.031 2260 328 1920 278
>0.80 – 1.00 >0.031 - 0.039 2200 319 1870 271
>1.00 – 1.25 >0.039 - 0.049 2150 312 1830 265
>1.25 – 1.50 >0.049 - 0.059 2100 305 1785 259
>1.50 – 1.75 >0.059 - 0.069 2040 296 1730 251
>1.75 – 2.00 >0.069 - 0.079 1990 289 1690 245
>2.00 – 2.50 >0.079 - 0.098 1880 273 1600 232
>2.50 – 3.00 >0.098 - 0.118 1830 265 1555 225
>3.00 – 3.50 >0.118 - 0.138 1775 257 1510 219
>3.50 – 4.25 >0.138 - 0.167 1720 249 1460 212
>4.25 – 5.00 >0.167 - 0.197 1670 242 1420 206
>5.00 – 6.00 >0.197 - 0.236 1610 233 1370 199
>6.00 – 7.00 >0.236 - 0.276 1560 226 1330 193
>7.00 – 8.50 >0.276 - 0.335 1505 218 1280 186
Other strength levels On request

1) tolerance on tensile strength + / - 7.0 % in accordance with En 10 270-3 grade 1.4310HS.

The tensile strength can be increased by 150–300 MPa (22 - 44 ksi) by tempering. Please click on heat treatment for further information. The tensile strength variation between spools/coils within the same production lot is ±50 MPa (7 ksi) maximum. The proof strength in the tempered condition is approx. 90% of the tempered tensile strength. The tensile strength values are guaranteed and are measured directly after production. During storage, the strength will increase marginally due to ageing. Depending on the storage conditions, ageing can increase the strength by 0 - 80 MPa (0 - 12 ksi). S-2140

Straightened lengths

After straightening the strength is approx. 7% lower.

Static strength, tempered and pre-stressed cylindrical helical springs

Sandvik Product Research

The strength data below is based on laboratory tests performed by Sandvik R&D. The data applies at 20°C in normal, dry atmosphere, unless otherwise stated. They are not guaranteed values but should be taken as recommendations in the choice of wire gauge, stress level, etc. A description of the testing procedure can be found, together with explanations under the following items:

E- and G-moduli
S-2130

Strength and mechanical testing
S-2131

Physical properties

The physical properties of a steel are related to a number of factors, including alloying elements, heat treatment and manufacturing route , but the following data can be used for rough calculations.

Density: 7.9 g/cm3, 0.29 lb/in3

Specific heat capacity

500 J/kg °C in the temperature range 50 - 100°C
0.12 Btu/lb °F in the temperature range 120 - 210°F

Thermal conductivity

Temperature, °CW/m °CTemperature, °FBtu/ft h °F
20 15 68 9
100 16 210 9
200 18 390 10.5
300 19 570 11.5

Resistivity

Temperature, °CμΩmTemperature, °FμΩin.
20 0.90 70 35.0
100 0.95 210 37.0
200 1.00 390 39.0
300 1.05 570 41.5
Thermal expansion 1)
Temperature, °Cper °CTemperature, °Fper °F
20 - 100 17 68 - 210 9.5
20 - 200 17.5 68 - 390 9.5
20 - 300 18.5 68 - 570 10.0

1) Mean values in temperature ranges (x10- 6)

Magnetic permeability, μmax: about 35

Shear modulus, MPa (ksi)

as delivered: approx. 71 000 (10 295)
tempered: approx. 73 000 (10 585)

Modulus of elasticity, MPa (ksi)

as delivered: approx.185 000 (26 825)
tempered: approx. 190 000 (27 550)
The strength will decrease by 3–4% per 100°C (180oF) increase in service temperature.

Corrosion resistance

It is very important to avoid corrosion in spring applications so as not to impair spring properties. Exera® 11R51/11R51HV are austenitic stainless steels and have sufficient corrosion resistance in most spring applications.

The corrosion resistance of the material is slightly higher compared to Sandvik 12R10 and standard ASTM 301, due to the addition of molybdenum.

Compared to other stainless spring steels, Exera® 11R51/11R51HV have superior performance. However, all austenitic steels of this type are susceptible to stress corrosion cracking (SCC) when in contact with chloride solutions at elevated temperatures.

Heat treatment

By tempering at 425°C (780°F)/0.5 - 4 h, the tensile strength will increase by about 150-300 MPa (20 - 45 ksi). If a shorter tempering time is used the tempering effect will be lower.

  • In continuous conveyor furnaces, where the holding time at temperature is very short (min. 3 minutes), the temperature can be increased to about 475°C (780°F).
  • In the `as delivered´ condition the ratio of proof strength/tensile strength is about 0.85. After tempering the ratio will be about 0.90.

Please note that tension springs coiled with initial tension must not be tempered at the same high temperature as other types of spring.

We recommend batch tempering at 250°C (480°F)/0.5–3 h, or continuous tempering in a conveyor furnace with a holding time of 3–5 minutes at about 300°C (570°F). S-2131. Click here for information on heat treatment in batch, continuous furnaces and on Why temper springs? S-2140

Bending

The minimum bending radius should not be less than half the wire diameter. The wire surface should be free from any tooling damage, since slight imperfections in the surface can lead to fracture, even at large bending radii.

Further information

Material datasheets and in-depth technical information about Sandvik Bioline grades and products are available on the Sandvik website, www.sandvik.com/medical.

Disclaimer: Sandvik 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.