~Understand the properties and benefits of various materials to ensure optimal performance and cost-efficiency~
Selecting the proper material for an application requires a general knowledge of what is available for use in our flat wire products, and it depends on the environment in which the spring/retaining ring is to be used.
Specifying the correct material can prevent additional costs and failure in operation. Carbon steel is the most commonly specified material. Although more costly than carbon steel, stainless steel has far superior corrosion resistance and higher temperature operating limits. Please find below a range of available materials and their characteristics. If you have any questions or require guidance, please don’t hesitate to contact our engineers at +44 (0)1435 866011 or enquries@tfc.eu.com.
Carbon Steel
TFC offers two standard carbon steel materials for retaining rings and wave springs. Carbon steel is highly magnetic, cost-effective and durable but has low corrosion resistance. Carbon steel products are oil-dipped for protection during shipment and shelf storage.
Maximum recommended operating temp.: 121°C / 250°F
Colour: various, including blue, black and grey
Oil Tempered SAE 1070-1090
SAE 1070-1090 high carbon spring steels are oil-tempered and are the most commonly used carbon steels. Tensile and yield strength are maximised because of the oil-tempered martensitic structure.
Hard Drawn SAE 1060-1075
SAE 1060-1075 high carbon cold drawn spring steels receive their strength from cold rolling.
In either temper, carbon steel is suited for use in a protected environment, as it corrodes if not oiled and sealed from the elements. Additional corrosion protection can be achieved with special finishes.
Stainless Steel
TFC offers three stainless steel materials for retaining rings and wave springs. 302 and 316 are standard materials for retaining rings, and 17-7 PH is the standard material for wave springs. Although more costly than carbon steel, stainless steel is only slightly magnetic, is more corrosion-resistant and can withstand higher temperature limits. Stainless steel products usually undergo ultrasonic cleaning and vapour degrease finishing processes.
302
302 is specified because of its combination of corrosion resistance and physical properties. 302 stainless steel gains spring temper condition by cold working. Although it is categorised as a nonmagnetic stainless, 302 becomes slightly magnetic because of the cold working. It cannot be hardened by heat treatment.
Maximum recommended operating temp.: 204°C / 400°F
Colour: silver-grey
316
316 is nearly identical in physical properties and heat resistance to 302. It provides more corrosion resistance because of the addition of molybdenum, particularly against pitting. As with 302, the magnetism of 316 increases as the wire is cold-worked. It cannot be hardened by heat treatment.
Maximum recommended operating temp.: 204°C / 400°F
Colour: silver-grey
17-7 PH Condition CH900
17-7 PH Condition CH900 is similar in corrosion resistance to 302 and offers high tensile and yield strength. In fatigue and high-stress applications, 17-7 outperforms even the finest grade of carbon steel. Spring properties are achieved by precipitation hardening Condition C to Condition CH900. As a result, the material may be subjected to a temperature of 343˚ C without a loss of spring properties. Its magnetism is similar to carbon steel.
Maximum recommended operating temp.: 343°C / 650°F
Colour: After precipitation hardening, 17-7 has a blue, brown or silver colour due to open-air heat treatment, although passivation provides a bright finish.
Super Alloy
TFC offers super alloys when carbon and stainless steel do not meet an application’s unique requirements. Super alloys maintain material properties in extreme operating conditions. These materials exhibit no magnetism and can be blue, brown, or silver in colour.
Materials may be heat treated in open-air or in an atmosphere-controlled furnace. Open-air heat treatment may produce scale, which often results in a dark residue. An atmosphere-controlled environment eliminates scale and produces a part with a brighter finish.
Inconel®1 X-750
Inconel X-750 is a nickel-chromium alloy and precipitation heat treated to a spring temper condition. Additional temper methods are available to achieve slightly different physical properties. TFC can also offer NACE (The National Association of Corrosion Engineers) approved materials to meet your requirements.
Maximum recommended operating temp.: 371°C / 700°F
A286 Alloy
A286 is a nickel-iron-based alloy that exhibits similar properties to Inconel X-750. Its spring temper condition is obtained by precipitation hardening.
Maximum recommended operating temp.: 538°C / 1000°F
Colour: blue/silver-grey
Elgiloy®2
Elgiloy is a cobalt-based alloy known for its high strength and excellent corrosion resistance. Elgiloy shows improved resistance to sulfide stress cracking over other NACE approved materials.
Maximum recommended operating temp.: 427°C / 800°F
Colour: Blue-brown in colour as a result of heat treatment
MP35N®3
MP35N is a nickel-cobalt-based alloy known for its high strength and corrosion resistance. It is often specified for oil and gas applications.
Maximum recommended operating temp.: 316°C / 600°F
Hastelloy®4 C-276
Hastelloy C-276 is a nickel-based alloy commonly used in chemical processing industries with proven performance in corrosive applications. Similar to other nickel-based alloys, it is ductile, easy to form, and has excellent resistance to stress corrosion cracking in chloride solutions. It can be used in environments up to 399˚ C.
Maximum recommended operating temp.: 399°C / 750°F
Monel®1 K-500
Monel K-500 is a nickel-copper-based alloy known for its excellent corrosion resistance, strength, and hardness properties. It can be used in environments up to 288˚ C.
Maximum recommended operating temp.: 288°C / 550°F
Copper
When magnetism or conductivity is important to your application, TFC offers a range of copper materials. There are two major types of copper alloys available as custom materials.
Beryllium Copper Alloy #25
Beryllium copper is nonmagnetic and one of the most electrically conductive materials TFC offers. Typically specified in a hard temper, it combines low modulus of elasticity and high ultimate tensile strength. The alloy gains its physical properties by precipitation hardening. In contrast to other copper alloys, beryllium copper has the highest strength.
Maximum recommended operating temp.: 204°C / 400°F
Phosphor Bronze, Grade A
Phosphor bronze is a nonmagnetic alloy with fair electrical conductivity. It is purchased in a spring temper condition to maximise spring characteristics and can be hardened only by cold working. Phosphor bronze exhibits fair spring properties and is rated a step below beryllium copper in performance.
Additional Materials
In addition to the materials listed above, TFC offers 410 Stainless Steel, Waspaloy and others. If you have questions on these materials or do not see your desired material listed, please get in touch with TFC Engineers for further details.
Manufacturing Specifications
Although industry and government specifications specify properties for flat wire, there are not many. In most cases, Smalley procures and/or rolls its material to internal specifications that are appropriate for the products they are used for. In addition to controlling tensile strength, thickness, and width, strict inspection procedures have been established to check for details such as edge contour, camber, coil set, and other physical imperfections.
Material Testing – Ultimate Tensile Strength
Tensile strength, rather than hardness, is used to measure the strength of our wire. This test method is preferred over hardness testing because flat wire may have different hardness values at various test points. As a result of cold rolling, the top and bottom surfaces (“A”) become harder as they are cold-worked over multiple passes. The round edge areas (“B”) are not compressed in the same manner, resulting in a different hardness. Tensile tests are more consistent as they evaluate the entire cross-section, not just a single point as in a hardness test.
Finishes
Whether you need added corrosion resistance or wish to change the appearance of your part, we can offer a wide range of finishing processes to ensure that your retaining rings and springs perform the way they need to in your application. Find out more about the finishes we offer HERE
To learn more about Materials and Finishes for Smalley products, download this Technical Overview
