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Stainless steels for springs and other demanding applications Sandvik Group The Sandvik Group is a global high technology enterprise with around 300 subsidiary compa- nies, 37,000 employees and activities in more than 130 countries. Sandvik’s operations are concentrated on its three core businesses of Materials Techno- logy,Tooling and Mining and Construction – areas in which the group holds leading global positions in selected niche markets.

Sandvik Materials Technology Stainless Sandvik Materials Technology is a world-leading strip and wire supplier of products with extensive added value in advanced metals, special alloys, metallic and ceramic resistance materials as well as process plants based on steel conveyor belts, and sort- ing systems.

Sandvik Materials Technology is a world leading manu- Quality assurance facturer of high quality stainless and high alloy steels. Sandvik Materials Technology has a quality man- Our production facilities are located in strategic markets agement system, approved by internationally recognised organisations.We hold for example: worldwide. ASME Quality System Certificate as a Material Organization, approval to ISO 9001 and QS To meet the needs of a variety of appli- from steel melt to the finished product. 9000 as well as approvals from LRQA, JIS and cations, we offer a wide range of steel Close controls throughout the entire other organisations as a material manufacturer. grades with different properties. Where manufacturing ensure high quality and special steel properties are called for, we product reliability. Environment can tailor our products to meet specific Our production equipment is customer demands. designed to produce strip and wire Environmental awareness is an integral part Our fully integrated mills include all within narrow dimensional tolerances of our business and is at the forefront of all stages in the manufacturing process, and with excellent surface quality. activities within our operation. We hold ISO 14001 approval.

We have full control of the production process

R & D Metallurgy Challenging demands Manufacturing process Tailor-made strip and wire

For more than a century, Melting is carried out in an Where special steel proper- By applying up to date tech- We have great flexibility our research has resulted electric arc furnace followed ties are called for, we can nology, we turn the latest when it comes to special in the development of new by AOD refining and ladle tailor our products to meet developments in alloying production of sizes, toler- grades of steel capable of furnace treatment before specific customer demands. and manufacturing pro- ances, grades, finishes, meeting the ever increasing the continuous casting. We cesses into the required forms of supply and demands of existing and also have vacuum remelting material properties. mechanical properties. new applications. facilities for materials with extremely high cleanliness.

2 Material for all types of springs and other demanding applications

Springs and other details made of stainless strip and wire from Sandvik Materials Technology are used in applications ranging from products in our daily lives such as cars, telephones and computers to parts in medical, aero- space and other special purpose applications.

Some springs will be exposed to millions Even though the main focus is set on of load cycles during service while others springs, our grades can also be used for have to maintain a constant force for a great number of other demanding several years.They may have to work in applications. corrosive environments, at high temper- We offer products with uniform mate- atures as well as in products where the rial properties and narrow tolerances to material needs to be completely non- ensure high production reliability for our magnetic. customers. Our modern and technically Where and how a spring will be used advanced production equipment, from is very important when selecting the steel melting to final product, provides precise spring material. It is equally clear, the ideal basis for any spring material i.e. that due to the complexity of possible a very clean steel with good surface combinations of required properties, quality. there may be no single material that can Our know-how from more than a fulfil all of them. century of spring steel production is also Our strip and wire product pro- at our customers disposal, both in the gramme comprises a wide assortment of form of comprehensive data sheets on grades, dimensions and properties with our steel grades and technical support specific characteristics for strength, and recommendations on the most suit- formability, relaxation resistance, fatigue able material for any given spring applica- strength, corrosion resistance or ductility. tion.

3 Material selection guide Sandvik grades

Corrosion resistance

Fatigue strength Sandvik SAF 2507 As-delivered tensile strength Sandvik SAF 2205 Sandvik 11R51

Sandvik Nanoflex Sandvik 9RU10 Sandvik 11R51 Sandvik 11R51 Sandvik SAF 2205

Non-magnetic Sandvik 12R10 / Sandvik 13RM19 12R11

Sandvik 11R51/ SAF 2205

Sandvik 9RU10 Sandvik 9RU10

Sandvik 11R51 Sandvik Nanoflex Sandvik Nanoflex

Sandvik SAF 2205 Sandvik Sanicro 75X Formability Sandvik 9RU10 Elevated The performance of our most import- temperature Sandvik Nanoflex ant grades for different properties is illustrated above. Sandvik 12R10/12R11 is used as a base of comparison. Relaxation Moving away from the centre, along resistance the desired axis indicates property improvement by steel grade, e.g. Sandvik SAF 2507 is the most corrosion resistant grade. Except for formability and as-delivered tensile strength comparison has been made for the materials in the tempered Sandvik, SAF 2205, SAF 2507, condition. Tempering is made by the Sanicro and Nanoflex are trademarks customer. owned by Sandvik AB. 4 A common requirement for spring appli- increased up to 20% by tempering (e.g. cations is a material with high strength so Sandvik 9RU10) or even as high as 70% that it does not become plastically (e.g. Sandvik Nanoflex). Precipitation hard- deformed in service. For stainless steels ening also makes the material more this is achieved by cold working the structurally stable at high temperature. For material to the required tensile strength. a normal austenitic stainless spring steel The degree of cold work together the service temperature is from -200°C with the chemical composition of the up to 250-300°C.The precipitation hard- steel determines the tensile strength.This enable steels can be used up to 350- means that there is great flexibility in the 450°C.This also gives a very good relax- combination of size and tensile strength ation resistance at elevated temperatures. that can be obtained. A less alloyed For retained spring properties at even austenitic stainless steel will deformation higher temperatures, a precipitation hard- harden more and it is therefore possible enable nickel base alloy can be used (e.g. to reach a higher maximum strength. Sandvik Sanicro 75X).

A high strength spring steel brings also While non-magnetic in the soft annealed high fatigue strength and low relaxation. condition, normal austenitic stainless Our standard austenitic stainless spring spring steels become more and more grades, Sandvik 12R10/12R11/T302 are magnetic during cold working. It is there- very good spring materials that in most fore difficult to combine non-magnetic cases will fulfil demands regarding corro- material with high strength. It can, how- sion resistance, mechanical strength, ever, be achieved by a carefully chosen fatigue and relaxation properties. For chemical composition (e.g. Sandvik special requirements, we have a wide 13RM19). range of grades with enhanced and problem solving properties. The corrosion resistance of stainless steels is brought about mainly by high contents Mechanical strength, fatigue strength and of chromium, molybdenum and nitrogen. relaxation properties can in most cold It is therefore difficult to improve the cor- worked austenitic stainless steels be fur- rosion resistance of austenitic stainless ther improved by a tempering heat treat- steels and still achieve a high mechan- ment. It is typically performed at 350- ical strength. Duplex (austenitic-ferritic) 480°C up to a few hours, depending on stainless steels (e.g. Sandvik SAF 2205/ grade. In most grades an increase in SAF 2507) on the other hand combine strength of up to about 12% can be excellent general corrosion properties achieved (e.g. Sandvik 12R10/12R11/T302/ and very good resistance to chloride 11R51/ 13RM19).The higher the strength stress corrosion cracking with a high before tempering, the higher is the tem- mechanical strength. pering effect. A tempering treatment will also lower internal stresses caused by All of the different Sandvik stainless steel forming. grades, available as strip or wire, are described in tables on page 6 and 10 There are also grades especially alloyed respectively. More technical information to give a high tempering effect, the so on each grade is contained on separate called precipitation hardenable grades, data sheets. Contact your local Sandvik which are very suitable for springs with sales office or refer to our website complicated shapes. The strength can be www.smt.sandvik.com

5 Strip

Stainless steel grade programme

Chemical compositions, nominal, %

Sandvik grade Standard designations 1) C Si Mn Cr Ni Mo Others SS EN ASTM UNS

AUSTENITIC STAINLESS STEELS 12R11 0.10 1.2 1.3 16.5 7 – – 2331 1.4310 (301) (S30100) 11R51 0.09 1.2 1.3 16.5 7.5 0.7 – 2331 1.4310 – – 13RM19 0.11 0.8 6.0 18.5 7 – N=0.25 – 1.4369 – – 3R12 ≤0.030 0.4 1.3 18.5 10 – – 2352 1.4306 304L S30403 316LVM ≤0.02 0.6 1.7 17.5 13.5 2.8 – 2253 1.4441 316LVM S31603 PRECIPITATION HARDENABLE STEELS 9RU10 0.08 0.5 0.9 16.5 7.5 – Al=1.0 2388 1.4568 631 S17700 Nanoflex ≤0.02 ≤0.5 ≤0.5 12 9 4 Cu=2.0 – – – – Ti=0.9 Al=0.4 1RK95 0.01 ≤0.5 ≤0.5 11.5 8.5 – Ti=1.2 – – – S45500 Cu=2.2 Nb=0.2 DUPLEX STAINLESS STEELS Springflex2) ≤0.03 0.5 0.9 22 5.5 3.2 N=0.18 – – – S32205 S31803 SAF 2507 ≤0.030 ≤0.8 ≤1.2 25 7 4 N=0.3 – 1.4410 – S32750 NI–BASE ALLOYS Sanicro 75X ≤0.030 0.3 0.6 16 72 – Al=0.7 – – – N07750 Ti=2.5 Nb=0.8 Fe=7.0

1) Designations within brackets indicate that the grade is close to the standard, but not completely fulfilled. 2) Cold rolled SAF 2205.

6 Tensile strength and size ranges

Sandvik stainless strip steels are manu- Sandvik grade Tensile strength Width Thickness factured in a wide range of sizes and ten- MPa mm mm sile strengths.The available ranges for dif- AUSTENITIC STAINLESS STEELS ferent grades in our standard production 12R11 800Ð1900 2Ð345 0.015Ð3 are shown in the table. Non standard 11R51 1700Ð2050 2Ð345 0.015Ð1.5 requirements are often available on spe- 13RM19 850Ð1600 2Ð345 0.015Ð3 cial request. 3R12 600Ð1300 2Ð325 0.015Ð2 It should be noted, however, that 316LVM 650Ð1300 2Ð320 0.015Ð5 there are some limitations. Strip thick- 2RK66 650Ð1200 2Ð270 0.015Ð3 ness limits the maximum tensile strength PRECIPITATION HARDENABLE STEELS and the minimum possible width. For 9RU10 1200Ð1700 2Ð360 0.015Ð3 thicknesses below 0.35 mm, the maxi- Nanoflex 950Ð1850 2Ð330 0.015Ð2 mum width is also reduced by 10 mm. DUPLEX STAINLESS STEELS Edge and surface finish are other para- SAF 2205 800Ð1500 2Ð300 0.015Ð3.5 meters that can restrict the possible size SAF 2507 900Ð1600 2Ð300 0.015Ð3.5 range. NI–BASE ALLOYS The standard tensile strength toler- Sanicro 75X 750Ð1350 2Ð200 0.015Ð4 ance is +/- 100 MPa, but closer tolerances can be supplied on request. Certain standard products are stocked in wide widths after final cold rolling to provide shorter delivery times. See the Standard programme below.

Standard programme = stock standard. = available combination.

Thickness Sandvik 12R11 Sandvik 11R51 Sandvik 9RU10 mm Tensile strength (MPa) Tensile strength (MPa) Tensile strength (MPa) 1300 1500 1700 1700 1900 2050 1300 1500 1700 0.015 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.50 0.60 0.70 0.75 0.80 0.90 1.0 1.5 2.0 2.5

7 Size tolerances Thickness tolerances Our cold rolling mills are equipped wider than 25 mm, the measuring point with automatic gauge control systems is at least 10 mm from the edge. For nar- for continuous thickness measurement rower strip the tolerance applies over and adjustment for process control. This the whole width of the strip. The stan- results in thickness tolerances superior dard tolerance class is T2. to those given in EN 10258. On strip

Thickness Width Thickness tolerances ± (mm) mm mm Tolerance class T2 T3 T4 <0.025 <250 0.002 0.0015 0.001 ≥250 0.003 0.002 0.0015 0.025Ð<0.050 <250 0.003 0.002 0.0015 ≥250 0.005 0.004 0.003 0.050Ð<0.10 <250 0.005 0.004 0.003 ≥250 0.006 0.005 0.004 0.10 Ð <0.15 <250 0.006 0.005 0.004 ≥250 0.007 0.006 0.005 0.15 Ð <0.20 <250 0.007 0.005 0.004 ≥250 0.008 0.006 0.005 0.20 Ð <0.25 <250 0.008 0.006 0.004 ≥250 0.009 0.007 0.006 0.25 Ð <0.30 <250 0.009 0.007 0.005 Width tolerances ≥250 0.011 0.008 0.006 The width tolerances are in accordance 0.30 Ð <0.40 <250 0.011 0.008 0.006 with EN 10258 regarding total range, but ≥250 0.012 0.009 0.006 with ±-tolerances around the nominal 0.40 Ð <0.50 <250 0.012 0.009 0.006 width instead of +-tolerances only. ≥250 0.014 0.010 0.007 Closer tolerances than BP can be sup- 0.50 Ð <0.60 <250 0.014 0.010 0.007 plied on request. ≥250 0.017 0.012 0.009 0.60 Ð <0.80 <250 0.017 0.012 0.008 ≥250 0.020 0.014 0.010 0.80 Ð <1.00 <250 0.019 0.013 0.009 ≥ Thickness Width Width tolerances ± (mm) 250 0.023 0.016 0.012 mm mm Tolerance class 1.00 Ð <1.20 <250 0.024 0.017 0.012 BN BF BP ≥250 0.026 0.018 0.013 <0.25 ≤40 0.085 0.06 0.05 1.20 Ð <1.50 <250 0.028 0.020 0.014 >40Ð125 0.10 0.075 0.06 ≥250 0.032 0.022 0.016 >125 Ð250 0.125 0.10 0.075 1.50 Ð <2.00 <250 0.033 0.023 0.017 >250 0.25 0.25 0.20 ≥250 0.038 0.026 0.019 0.25 Ð <0.50 ≤40 0.10 0.075 0.06 2.00 Ð <2.50 <250 0.035 0.025 0.017 >40Ð125 0.125 0.10 0.075 ≥250 0.040 0.028 0.020 >125Ð250 0.15 0.11 0.085 2.50 Ð 3.00 <250 0.040 0.028 0.020 >250 0.30 0.25 0.20 ≥250 0.043 0.030 0.022 0.50 Ð <1.00 ≤40 0.125 0.10 0.075 >40Ð125 0.125 0.11 0.085 >125Ð250 0.20 0.125 0.10 >250 0.35 0.30 0.25 1.00 Ð <1.50 ≤40 0.125 0.11 0.075 >40Ð125 0.15 0.125 0.085 >125Ð250 0.25 0.15 0.11 >250 0.50 0.35 0.30 1.50 Ð < 2.50 ≤40 0.20 0.125 0.10 >40Ð125 0.20 0.125 0.10 >125Ð250 0.30 0.20 0.125 >250 0.50 0.40 0.30 2.50 Ð3.00 ≤40 0.25 0.15 0.125 >40Ð125 0.25 0.15 0.125 >125Ð250 0.30 0.20 0.125 >250 0.60 0.50 0.40

8 Shape tolerances

Flatness Straightness Deviation from Deviation from flatness in cold rolled The figure to the right shows how devi- Strip width straightness, a strip is difficult to specify, because it can ation from straightness is defined. The appear in a variety of forms. Crossbow, values in the table refer to slit strip and waviness and coil set are measurable – give the deviation from straightness for a see illustration.These different forms can length of 1 metre. The Sandvik standard also act in combination. One form or the finish is R1. Measured length, L other will predominate, depending on Deviations can be determined for other the width, thickness and tensile strength lengths using the following formula; 2 of the strip. a = b x L Maximum deviation from straightness, For strip less than 50 mm wide, devi- where in mm mesured on a length of 1 m. ation from flatness can be stated as a = the sought for deviation Width Tolerance class crossbow in percentage of width or as from straightness in mm for mm R1 R2 R3 coil set in mm/300 mm lengths. Both a given length, L, in m. TENSILE STRENGTH 1100-1800 MPa these properties can be measured with b = deviation from straightness <8 7 4 2.5 suitable instruments. The coil set is usu- according to the table 8Ð<20532 ally measured with the sample standing Comparison between two lengths, 20 Ð<50 4 2.5 1.5 on the edge. For maximum values, see L1 and L2 50 Ð <125 2.5 1.5 1.25 the table below. ≥125 2 1 1 2 Where wider strip is concerned, devi- a1 L1 TENSILE STRENGTH OVER 1800 MPa — = — ations from flatness occur in forms that are a ()L <10853 2 2 difficult to measure. Coil set, however, can 10 Ð<20 6 4 2.5 be measured rather easily, and maximum 20 Ð<50 5 3 2 values can therefore be given. 50 Ð <125 3 2 1.5 ≥125 2 1.5 1 The standard Sandvik finish is toler- Deviation from flatness ance class P1 (normal flatness), which corresponds to the requirements for a wide spring steel intended for slitting. In waviness coil set crossbow cases where the full width of the material is to be used and a superior standard of flatness is required, this should be the subject of special discussions.

Maximum deviation from flatness for cold rolled strip with a tensile strength exceeding 1100 MPa Tolerance class P1 Tolerance class P2 Tolerance class P3 Width Coil set Crossbow Coil set Crossbow Coil set Crossbow mm mm/300 mm % of width mm/300 mm % of width mm/300 mm % of width <20 35 0.6 20 0.4 10 0.3 20 Ð<50 35 0.8 20 0.6 10 0.4 ≥50 35 Ð 20 Ð 10 Ð

Finishes

Edge finish Surface finish Sandvik strip steel can be delivered Strip is normally supplied with a bright with a variety of edge finishes to suit and smooth surface. customers’ requirements. Surface roughness Class Class limit Class mean Mill edge. Untreated edge, generally Deburred edge. Slit edge from which R ,µm R ,µm with an uneven contour. the burr has been removed. a a Y6 0.2 Ð0.5 0.32 No width tolerance is normally stated. Y7 0.1 Ð0.25 0.16 Y8 0.05Ð0.125 0.08

Slit edge. Edge with the slitting burr left Round edge. Edge completely rounded. on.This edge is obtained by slitting with Obtainable in widths up to 150 mm and a circular shear. thicknesses over 0.1 mm.

9 Round and flat wire

Stainless steel grade programme

Chemical compositions, nominal, % Sandvik grade Standard designations C Si Mn Cr Ni Mo Others SS EN/ISO ASTM JIS UNS AUSTENITIC STAINLESS STEELS 12R10 0.08 0.6 1.2 18 9 Ð Ð 2331 1.4310 302 SUS 302/ Ð 304ÐWPB T302 0.07 0.5 1.3 18.5 8 Ð Ð 2331 1.4310 302 SUS 302/ Ð 304ÐWPB 11R51 0.08 1.5 1.8 17 7.5 0.7 Ð 2331 1.4310 HS 302 SUS 302 Ð Mod. 5R10 0.04 0.4 1.3 18.5 8.5 Ð Ð 2333 1.4301 304/ Ð S30400/ 304H S30409 5R60/5R62 2) 0.05 0.6 1.2/ 17 11 2.6/2.1 2) Ð 2343 1.4401 316 SUS 316 Ð 1.5 WPA 8R70 0.05 0.5 1.5 17.5 11 2.1 Ti≥6x(C+N) Ð 1.4571 (316Ti) Ð Ð 2RK66 0.020 0.4 1.8 20 25 4.5 Cu=1.5 2562 1.4539 904L Ð N08904 11RM20 0.09 0.5 5.9 17.0 5.0 Ð Ð Ð 1.4371 Ð Ð Ð 13RM19 0.11 0.8 6.0 18.5 7 Ð N=0.25 Ð 1.4369 Ð Ð Ð PRECIPITATION HARDENABLE STEELS 9RU10 0.08 0.5 0.9 16.5 7.5 1) Ð Al=1.0 2388 1.4568 631 SUS 631 Ð J1ÐWPC Nanoflex3) ≤0.02 0.5 0.5 12 9 4 Cu=2.0/ Ð Ð Ð Ð Ð Ti=0.9/ Al=0.4 DUPLEX STAINLESS STEELS SAF 2205 0.020 0.4 1.5 22 5.5 3.0 N=0.17 2377 1.4462 Ð Ð S31803 NI–BASE ALLOYS Sanicro 75X 0.030 0.3 0.5 16 72 Ð Ð Ð Ð Ð Ð N07750

1) For better cold formability the upper limit for the Ni content can be increased to 8.30% in accordance with note d in EN 10270-3. 2) Sandvik 5R60 flat rolled wire with Mo 2.6 and Sandvik 5R62 round wire with Mo 2.1. 3) In-house grade designation is IRK91.

Tensile strength Size range Sandvik Sandvik Sandvik and size ranges 2RK66 1) SAF 2205 1) 13RM19 1) ROUND SPRING WIRE 0.15Ð0.20 1720 2250 2200 Round spring wire > 0.20Ð0.30 1670 2200 2150 For tensile strength please refer to data- > 0.30Ð0.40 1670 2100 2100 sheet: > 0.40Ð0.50 1610 2100 2100 Sandvik 12R10 S-2160 > 0.50Ð0.65 1560 2000 2000 Sandvik 9RU10 S-2161 Sandvik 11R51 S-2162 > 0.65Ð0.80 1560 2000 2000 Sandvik 5R60/5R62 S-2163 > 0.80Ð1.00 1500 1900 1900 Sandvik 8R70 S-2164 > 1.00Ð1.25 1450 1900 1900 Sandvik SAF 2205 S-2170 > 1.25Ð1.50 1450 1800 1800 Sandvik 2RK66 S-2171 > 1.50Ð1.75 1400 1800 1800 Sandvik 13RM19 S-2172 > 1.75Ð2.00 1400 1650 1800 Sandvik Sanicro 75X S-2174 > 2.00Ð2.50 1400 1650 1650 Sandvik Nanoflex S-2614 > 2.50Ð3.00 1400 1650 1650 The tensile strength for Sandvik > 3.00Ð3.50 1400 1650 1500 Nanoflex and Sandvik 11RM20 depends > 3.50Ð4.25 1350 1550 1500 on the application and can be supplied > 4.25Ð5.00 1350 1550 on request. > 5.00Ð6.00 1350 1450 The size range for wire is 0.15–10.00 > 6.00Ð7.00 1300 1450 mm (depending on steel grade) – wire > 7.00Ð8.50 1240 1450 with coated surface 0.20–10.00 mm and wire with bright surface 0.15–6.00 mm. 1) +/- 100 MPa

10 Flat rolled wire Sandvik grade Tensile strength Proof strength 1) nominal nominal

Rm,MPa Rp0.2 ,MPa Sizes 12R10 800Ð1900 0.85 * Rm Flat rolled wire is available in widths from 11R51 800Ð2050 0.85 * Rm 0.5-7.0 mm and thicknesses from 0.05- 9RU10 850Ð1700 0.85 * Rm 4.00 mm and with round or sharp rolled SAF 2205 800Ð1700 0.85 * Rm edges. 5R10 800Ð1300 0.85 * Rm 5R60 800Ð1300 0.85 * Rm 2RK66 800Ð1300 0.85 * Rm Other strength levels can be supplied on request. 1) In the cold rolled condition.

Size tolerances Shape tolerances

Round wire Re-straightened round wire The tolerances below are standard. For production of torsion springs and Closer tolerances can be supplied on bent parts with straight ends, polished H request. Ovality is according to the wire in the re-straightened condition is L standard EN 10270-3. The tolerances used. for roundness, i.e. the difference between the largest and smallest diame- Wire diameter Distance Archeight in Coil Coil ter in the same cross-section of the wire, mm L, mm centre H, mm ID, mm weight, kg do not exceed half of the tolerance of 0.25Ð0.31 200 10 300 10Ð12 the diameter. >0.31Ð1.35 400 40 400 12Ð40 >1.35Ð1.50 600 70 600 40Ð60 >1.50Ð2.50 800 130 600 60Ð70 Wire diameter Diameter tolerance mm mm +/- 0.15Ð 0.20 0.005 >0.20Ð 0.40 0.008 Circular and helix cast for Flat rolled wire >0.40Ð 0.80 0.010 round wire Straightness >0.80Ð 1.60 0.015 1. Helix cast Max (X)1.5 mm for 500 mm length (L). >1.60Ð 3.20 0.020 2. Circular cast >3.20Ð 6.00 0.025 >6.00Ð10.00 0.035 2. L X

Flat rolled wire Thickness and width tolerances should 1. be agreed for each order. Please refer to The values are according to the standard brochure S-2180. EN 10270-3.

11 Surface finish – round wire

Wire can be drawn in powder or in oil, which results in either a coated or a bright drawn surface. Both finishes are also available with a thin layer of nickel, which results in a wire with very good lubricating properties and better tolerances in production.

Coated surface Nickel coated surface The coating consists of a lubrication layer, Nickel is one of the most common metal which is practically free from chlorides coatings for spring wire in stainless steels. (approx. 0,1 %) and made up mainly of Mechanical properties are the same as sodium and calcium compounds. The for the basic wire but nickel coating coating is sensitive to moisture, which improves spring coiling precision, gives a means that the wire must be protected better production yield and reduces tool during storage and transit. The coating wear. After cleaning, nickel coated springs can be left on the finished spring, but it are brighter and have very good soldering can also easily be removed, using alkaline properties. agents. All Sandvik standard grades can be supplied with nickel coating in the coated Bright surface or bright drawn condition. Bright drawn wire has a surface covered Nickel is not resistant to corrosion in with a very thin oil film. sour environments such as oxidising acids Mechanical polishing of lubricated wire and nitric acid will dissolve the nickel layer meets the standards for a clean, bright completely. surface which are often set for stainless springs – not only for appearance but also for hygiene. A suitable lubricant should be added in spring coiling, except for the smallest wire diameters.

Nickel Lubricant Spring wire

12 Our well developed distribution system means that we can provide a high quality delivery service wherever our customers are located. Forms of supply

Strip Strip material can be delivered in the following forms: Coils: Widths >13 mm Pancake coils: Widths ≤13 mm Bundles: Widths ≤13 mm oscillated with welded strands of max. 650 kgs Plastic spools: Widths ≤13 mm oscillated with welded strands of max. 100 kgs Lengths of 400-4000 mm

Wire Wire is supplied in quantities and delivery forms adapted to customer requirements. We supply coils, spools and straightened lengths in quantities of a few kilograms up to units weighing up to one ton. See brochures S-2120 and S-2180 for details.

Further information on packaging can be found on our internet website www.smt.sandvik.com BSNVKMTRASTCNLG,S-1 1SNVKN WDN HN 4 62 00 A TI 4 62 25,FAX WIRE +4626-26 PHONE+4626-263000FAX STRIP+4626-260257, SWEDEN, AB SANDVIK MATERIALS SE-81181SANDVIKEN, TECHNOLOGY, www.smt.sandvik.com 0262

S-3411-ENG. Jan 2003. Printed in Sweden: AB Sandvikens Tryckeri. Ason&Co.