About SEEGER® Rings
Maximum-quality products are essential to Seeger-Orbis
The reliability of SEEGER® products results from ongoing engineering development, reliable manufacturing processes, and a sophisticated quality assurance system certified to TS16949.
The raw materials used for manufacture are subject to stringent quality standards with inspections performed at all levels of production, including packaging and outgoing goods. All processes and inspection sequences are designed to ensure quality adherence; and test procedures are recorded and updated continuously.
Computer-assisted testing devices have been specially developed to enable the continuous monitoring and documentation of the production process. The Seeger-Orbis quality assurance system fulfills the maximum demands of the automobile industry.
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SEEGER® retaining systems are manufactured from high-grade spring steels which are selected on the basis of the special characteristics required for the various ring applications. The rings are hardened using the appropriate heat treatment processes (bainitic hardening or isothermal austempering) to enable them to absorb high axial forces when fitted in the groove, ensuring the rings can be assembled without any issues. It is interesting to note that larger rings have a lower hardness, because the stresses placed on them during assembly are not as high as the stresses placed on smaller rings. The hardness of rings is specified in terms of Rockwell or Vickers values depending upon ring size.
Carbon Spring Steel
Seeger-Orbis selects raw material based on its performance characteristics, such as a high modulus of elasticity, high yield point, high elastic elongation and good hardening abilities; which are best achieved by spring steels in accordance with DIN 17222. The material C75S, material No. 1.1248, is a good example. This is a high-purity carbon spring steel with a low phosphorus and sulphur content. This material, along with Mk 58 and spring steel wire in accordance with DIN 17223, are the primary steels used to manufacture Seeger retaining systems.
In addition to the above-mentioned carbon spring steels, corrosion-proof materials are also used. The following materials are also available to manufacture SEEGER® retaining rings:
Corrosion-Resistant Stainless Steels
1. Designation: X 39 CrMo 17.1, Material Number 1.4122 As a hardenable martensitic chrome steel, this material does not have the resistance of austenitic chrome nickel steels, but it suffices for numerous applications and is used above all in the manufacture of smaller and medium-size rings.
2. Designation: X l2 CrNi 17 7, Material Number 1.4310 This material is an austenitic, corrosion-proof stainless steel which is particularly suitable for work hardening. Both SEEGER® rings to DIN 471/472 with dimensions of more than 100 mm nominal diameter (concentric form) and snap rings SW/SB can be manufactured from this material.
All stainless steels are susceptible to specific types of corrosion, which in certain circumstances, may lead to sudden failure of the ring assembly due to brittle fracture. It is absolutely necessary to pay attention to the specific characteristics of these materials when used in conjunction with certain corrosive media. The risk of stress corrosion can be minimized by reducing the tension. Therefore, the depths of the grooves should be designed in such a way that the rings are assembled with a minimum of pretension.
Tin Bronze CuSn8, Material Number: 2.1020.34, DIN 17662 Although it has a high strength, this material has a lower elastic deformation than spring steel. Therefore, rings manufactured from this bronze tend toward plastic deformations in the higher-stress smaller dimensions; although, a tight fit in the groove is almost always guaranteed. In comparison with spring steel, this material's lower modulus of elasticity (115.000 N/mm²) results in a reduction in its load bearing capacity and its detaching speed. However, tin bronze is antimagnetic, and even at low temperatures, shows no tendencies towards embrittlement.
Spring steel components can basically be hardened in accordance with two different processes:
1. Martensitic Hardening with Subsequent Tempering:
By quenching from the austenitizing temperature (approx. 800-820°C) in oil at room temperature, a martensitic structure is achieved - which will attain the required degree of hardness and toughness by subsequent tempering in a salt bath or in air.
2. Isothermal Austempering:
By isothermic conversion in the bainite phase, the desired structure is achieved by quenching in molten salt with the following advantages:
- extreme toughness and thus higher permanent strength and a reduced risk of hardening cracks and better elimination of stress peaks
- less distortion due to a smaller temperature difference
- less sensitivity to hydrogen embrittlement
- energy saving and cost saving in comparison with martensitic hardening, as the subsequent tempering is inapplicable
Apart from a few exceptions, all Seeger retaining systems are always hardened by isothermic conversion.
To achieve corrosion protection adequate for storage and transport, most of our rings are zinc-phosphated and oiled. This results in a salt spray test resistance of 8 hours. If higher demands are placed on corrosion resistance, Seeger-Orbis retaining systems can be supplied with special surface finishes, which are applied either galvanically or mechanically. In the case of galvanically produced surface finishes, zinc is preferred for pollution control reasons. To improve corrosion protection features, chromate treatment is additionally carried out (hex-chrome VI free). The use of copper, nickel or chrome coatings is only used in special circumstances.
During both the cleaning phase and the coating processes of galvanic treatment, hydrogen atoms may be absorbed. In certain circumstances, this may lead to a hydrogen-induced delayed brittle fracture. As a rule, the risk of brittle fracture is avoided in Seeger-Orbis products by means of thorough degasification of the material after the galvanization process, but this risk cannot be excluded completely (see also DIN 267, part 9).
In a special process, zinc or tin particles (or mixtures of these) are hammered or impinged onto the ring in a drum by means of glass balls of a suitable size.
The standard Seeger-Orbis range contains a large number of galvanized and mechanically plated rings to DIN 471/472 and DIN 6799, which are available from stock.
The following surface treatment processes can also be mentioned:
Electrophoretic Painting (also named KLT-Coating)
The phosphated surface is additionally protected in a subsequent painting process. This produces outstanding corrosion resistance. However, the relatively thick coating of approximately 0.04 mm must not be overlooked.
Other processes of surface coating based on hardened synthetic resin and zinc compounds are available upon request.
All of the processes mentioned above require specific batch sizes to be economically justifiable. When using Seeger-Orbis retaining systems with additional surface coatings, please note that the coating thickness increases the ring thickness, and this must be taken into account when dimensioning the grooves. The product designations include details of the coating material (abbreviated with the coating thickness in µ). The surface protection designations are given after the ring designations. Please refer to the Seeger-Orbis data charts or the Seeger-Orbis range and price list for further information concerning ring designations.