The plating film compositions of both plating methods are metallic chromium. However, decorative chrome plating is a plating method that aims at appearance and corrosion resistance, while hard chrome plating is a plating method that mainly aims at hardness and wear resistance. Therefore, decorative chrome plating does not need to have a thick film, while hard chrome plating needs a film thickness of at least 10 to 100 μm. Similarly, decorative chrome plating mostly has nickel plated as undercoating in order to increase corrosion resistance, while hard chrome plating is normally applied directly onto a substrate because it attaches greater importance to adhesion force.

Chromating is a chemical conversion coating applied onto zinc plating or zinc alloy plating. After zinc plating surfaces are activated, by immersing them into a chromate solution mainly consisting of hexavalent chromium, a chromate film will be deposited onto the zinc plating surfaces. Chromate films have excellent corrosion resistance because of their self-healing action. Chromate films used to be formed using hexavalent chromium plating solutions. However, because the films formed this way contain hexavalent chromium, in recent years, chromate films formed using trivalent chromium plating solutions are becoming mainstream because of environmental considerations.

Hard chrome plating is electrolytically deposited as metallic chromium by reducing hexavalent chromium in a plating solution. This means that hexavalent chromium is not contained in hard chrome plating films. The results of demonstration experiments conducted by Technology Research Institute of Osaka Prefecture have revealed that hexavalent chromium does not dissolve from our plating. For details, refer to this PDF file.

Hard chrome plating can be applied to steel, copper, brass, stainless steel, aluminum, and titanium.

The size of workpieces to which hard chrome plating can be applied differs according to materials, accuracy, specifications, and other conditions. For any inquiries about target workpieces, please send an inquiry form or phone us.

Hard chrome plating has poor throwing power and macrothrowing power, which means that it is very difficult to plate to a uniform thickness over a complex-shaped workpiece. However, Otec manufactures dedicated jigs to enable hard chrome plating to be applied to various shaped workpieces. For any inquiries about target workpieces, please send an inquiry form or phone us.

Yes, it is possible. We can also handle precision grinding, honing, and other machining for hollow cylindrical parts. However, restrictions apply to machining, depending on the relationship between the diameter and length. For any inquiries about target workpieces, please send an inquiry form or phone us.

This is technically possible, but we do not handle hard chrome plating on large castings at present. For hard chrome plating, anodic electrolysis must be performed in a plating bath to increase adhesion force. However, if a casting is subject to anodic electrolysis, free carbon will dissolve from the casting, causing plating defects such as pits and particles.

It is difficult to apply hard chrome plating directly onto PVD coatings. PVD films must be removed. The same applies to hard chrome plating on CVD coatings and thermal spray coatings.

Chrome plating can be removed by grinding, immersion into hydrochloric acid, or anodic electrolysis in a plating solution, and then reapplied.

Product samples are available for Tfe-Lok and Chroamor. For other trial products, please consult with us.

Teflon coating is a surface treatment method that applies a membrane of polytetrafluoroethylene (PTFE) onto workpiece surfaces, while Tfe-Lok is a surface treatment method that is based on chrome plating and physically embeds PTFE into cracks on the chrome plating surface. For this reason, the film strength of Tfe-Lok is as high as that of chrome plating, providing excellent durability and wear resistance.

Tfe-Lok can be reapplied by removing its film.

The plating thickness of Tfe-Lok is 50 μm or more.

The maximum surface roughness of Tfe-Lok is approximately 1.0S because its plating surface is etched when polytetrafluoroethylene (PTFE) is embedded.

Several types of Tfe-Lok surface condition are available, ranging from smoothness with a surface roughness of approximately 1.0S (as above) through to various types of satin finish specifications, any of which can be selected according to customer needs.

The maximum size of a workpiece that can be Tfe-Lok plated using the current facilities is 3,500 mm in overall length. For any workpieces larger than the maximum limit, please consult with us separately.

Tfe-Lok can be applied to complex-shaped workpieces as long as chrome plating can be applied to them.

The hardness of Tfe-Lok is approximately Hv850.

Only Otec provides Tfe-Lok plating in Japan.

We will send a Tfe-Lok sample at your request. Please send an inquiry form.

The heat resistance of Tfe-Lok is below the melting point of PTFE (327ºC). For continued use, we recommend that Tfe-Lok be used around 250ºC.

Chroamor is an alloy plating of chromium and carbon. Chroamor has an amorphous structure when a plating film is deposited, but the structure changes to a crystal structure when it is subject to heat treatment. When the structure changes to a crystal structure, the plating film hardens.

Chroamor can be reapplied by removing its film.

The maximum plating thickness of Chroamor is 5 μm. It is possible to plate to a thickness exceeding 5 μm, but macrocracks will occur. Chroamor forms a crack-free and very hard film that provides sufficient wear resistance and corrosion resistance even when its thickness is 5 μm or less.

Chroamor forms a thin film with a thickness of 5 μm or less, which means that its film thickness is less uneven than other platings such as hard chrome plating. For this reason, Chroamor has been used for a variety of precision molds and other applications.

Chroamor cannot be applied onto other surface treatments such as chrome plating.

Chroamor-plated workpieces cannot be subject to abrasive machining because its film is very thin.

Because Chroamor-plated workpieces cannot be subject to abrasive machining, its surface roughness is influenced by the surface roughness of its substrate. Rolls can be finished with a surface roughness of approximately 0.4S.

We can handle workpieces that can be put in our plating bath with dimensions of 400 mm × 400 mm × 3,000 mm. For any workpieces larger than the maximum limit, please consult with us separately.

Only Otec provides Chroamor plating in the world.

We will send a Chroamor sample at your request. Please send an inquiry form.

We will send catalogs and specific technical documents about Chroamor at your request. Please send an inquiry form or phone us.

The maximum size of rolls that we can machine in-house is 600 mm diameter × 6,000 mm long. Rolls larger than the maximum size can be machined by our partner companies. For details, please send an inquiry form or phone us.

Yes, we can. We have a track record in manufacturing a large number of precision rolls with a special structure, such as double wall coaxial rolls for forming films or sheets.

We can repair rolls by replacing shafts, overlaying, or taking other measures. First, please let us look at the target roll and then let’s discuss how to repair it. However, depending on the condition of the roll, we may recommend replacing with a new roll.

We have much experience in repairing knife rolls. Please consult with us about any repair requests such as repairing blade edges and structural repairs.

The precision level of rolls that we can machine differs according to the size, shape, material, and other conditions of the roll to be machined. We have a track record in machining a large number of precision rolls in the order of 1/1,000 mm. Please consult with us, based on the actual drawings of the target roll.

We do not perform engraving in-house, but we can handle engraving in collaboration with our partner companies.