Batteriekontakt Gutekunst FormfedernAdditional Surface treatments can not only make machined surfaces smoother or more attractive. You can also use the electric conductivity of Form springs , Flat springs , Contact springs , Leaf springs , Stamped and bent parts and Laser parts improve or even produce first. Depending on the spring material to be refined and the conductive application, different surface technologies are available:


Copper plating (Cu): Corrosion protection and improved electrical conductivity

With this galvanic surface treatment, different metals such as spring steel, stainless steel, brass or aluminum can be reworked. Copper plating not only protects the metal from corrosion and fretting corrosion (tribo-oxidation) – it also increases the electric conductivity of Form springs and reduces the risk of sparks. This is particularly important for contact springs that are to be used in explosion-proof environments. Another advantage: the copper layer acts as a diffusion barrier and makes hardening and soldering of the components easier.

An overview of copper plating:

  • Corrosion protection
  • improved electrical conductivity
  • Protection against fretting corrosion
  • Build-up layers with undersize
  • improved run-in properties
  • Diffusion barrier (hardening / soldering)
  • Anti-sparking in an explosion-proof environment
  • Conductivity copper σ ~ 56 MS / m
  • Specific resistance Ω ~ 0.018 µΩ m

Gold plating (AU): decorative and wear-resistant


Are suitable for gilding Spring steel , stainless steel , Copper as well as aluminum and its alloys. Gold plating increases protection against corrosion, makes the technical spring wear-resistant and seawater-resistant, and improves it conductivity , reduces their contact resistance and increases their solderability. In addition, gold ensures a high surface hardness: between 120 and 190 HV (Vickers hardness) are available with a purity of 99.8 percent. And decorative are gold-plated Metal clips and contact springs too.

Gilding at a glance:

  • Corrosion protection
  • high seawater resistance
  • wear-resistant
  • improves electrical conductivity
  • lower contact resistance
  • easy to solder
  • Surface hardness 120 to 190 HV
  • Purity 99.8%
  • decorative
  • Gild conductivity σ ~ 44 MS / m
  • Specific resistance Ω ~ 0.022 µΩ m


Silver plating (Ag): food safe and very good conductivity

One of the most important processes for surface finishing is silvering. It can be used with copper, spring steel, and brass aluminum can be applied. Silver-plated Form springs , Flat springs , Leaf springs , Spring clips and Contact springs offer a whole range of advantages: They are chemically resistant and food safe , exhibit a greatly increased conductivity and a lower contact resistance, are easy to solder and have less tendency to spark off. In addition, the silver forms a sliding layer in the high temperature range of up to 850 degrees Celsius.

Silver plating at a glance:

  • great improvement in electrical conductivity
  • less tear-off sparks
  • chemically resistant
  • Sliding layer in the high temperature range up to 850 degrees Celsius
  • lower contact resistance
  • food safe
  • good solderable
  • Silver conductivity σ ~ 62 MS / m
  • Specific resistance Ω ~ 0.016 µΩ m

Nickel plating (Ni): very good corrosion protection and magnetic

Technical springs received with the nickel-plated surface an improved conductivity and a very good one Corrosion protection over a wide temperature range. So treated Metal springs are also wear-resistant and resistant to chemicals. The applied nickel layer acts as a diffusion barrier, makes soldering the components easier and makes them magnetic.

Nickel plating at a glance:

  • Corrosion protection over a wide temperature range
  • wear-resistant
  • improved electrical conductivity
  • solderable
  • Chemical resistance
  • Repair of surfaces
  • Diffusion barrier
  • Ferromagnetic
  • Nickel-plated conductivity σ ~ 13 MS / m
  • Specific resistance Ω ~ 0.082 µΩ m


Tinning (Sn): chemical resistant and food safe

Tinned Form springs , Flat springs , Contact springs , Leaf springs , Stamped and bent parts and Laser parts are particularly interesting for the electrical and food industries. With this type of Surface treatment With the help of electricity, an even material coating with very good layer thickness distribution on the Metal spring upset. The process can be used with spring steel, stainless steel, brass or copper. Tinned components are chemical and corrosion resistant and let yourself just solder . They have a low contact resistance and very good sliding properties.

Tinning at a glance:

  • food safe
  • good solderable
  • good corrosion protection
  • good sliding properties
  • low contact resistance
  • chemically resistant
  • very good layer thickness distribution
  • Tin conductivity σ ~ 9 MS / m
  • Specific resistance Ω ~ 0.11 µΩ m


Delta®-Tone: coatings with tailor-made properties

With a Delta®-Tone coating, tailor-made solutions for Functional characteristics , Friction behavior and the corrosion resistance of metal spring surfaces. With the Delta®-Tone process, an inorganic and micro-layer-forming basecoat is applied to the component, which contains zinc and aluminum flakes. During the subsequent baking process, a silver-metallic, shiny coating with a uniform thickness is created. This has excellent corrosion protection properties and ensures very good electrical conductivity. This enables cathodic protection and avoids the risk of hydrogen embrittlement.

Depending on the requirements for the coating, users can select the right Delta® basecoat:

  • Delta®-Tone 9000 is especially suitable for Metal springs , Spring band clamps and Stamped and bent parts .
  • Delta-Protekt® KL 100 was specifically developed for threaded parts and is often used in the automotive industry. The base layer can withstand constant temperatures of 96 hours at 180 degrees Celsius.
  • Delta-Protekt® KL 105 with integrated lubricant makes the use of a topcoat superfluous. The coating is adjusted to the specific coefficient of friction. The 2-in-1 system saves costs.
  • Delta-Protekt® KL 130 is dark gray and intended as a base for black covering tones, as the impact points are no longer visible.
  • Delta-Protekt® KL 120 is particularly suitable for connecting elements with threads as well as for springs or spring band clamps. The red and white corrosion resistance goes far beyond the requirements of other surface finishes.


Electric Isolation

All the coatings presented lead to improved electrical conductivity of shaped springs, flat springs, leaf springs, spring clips and contact springs. If the surface treatment of the technical spring is to have an isolating effect, are Thick-film passivation, powder coating, galvanizing or phosphating the right procedures.


Surface treatment at Gutekunst form springs

Would you like more information about Surface treatments or need advice on the right surface technology for your Shaped spring , Leaf spring , Contact spring , Flat spring , Laser part or your Stamped and bent part ? Then contact our experts. The engineering department of Gutekunst Formfedern GmbH can be reached by phone at (+49) 07445 8516-30 or by e-mail to:


Individual manufacture of contact springs

You need the right one Contact spring or one special battery contact for your application? Then send your CAD data, a drawing or a sketch, as well as information on the installation situation, operational environment and the desired function via the following Inquiry button contact springs or at .


Inquiry form contact springs from Gutekunst Formfedern

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Electrically conductive surface treatments
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