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Optical Coatings

Optical Coatings


The Optics Division is dedicated to metal finishing optical components such as a wide variety of optical lenses, x-ray incident grazing mirrors, lenticular rolls, and components used in space telescopes. We also have the capability to handle a wide variety of difficult precision engineering plating jobs. The Optics Division offers “Optical Grade Electroless Nickel” and Optakoat for the photonic, optic, and diamond turning industries.


We have the ability to handle small parts such as contact lens molds. We can plate them with our Optical Grade Electroless Nickel Tech Sheet, link to more information.

Optakoat I & II

Optakoat is a totally amorphous non-laminar nickel phosphorous coating. It reaches purity and phosphorous levels unattainable with even the finest optical grades of electroless nickel. It remains non-magnetic even when exposed to heat. An Optakoat deposit was tested by both Lawrence Livermore National Laboratory and the Marshall Space Flight Center. The conclusions were that Optakoat can outperform electroless nickel phosphorous deposits in the areas of low tool wear. In fact, a Talystep profile and scanning an Electron Microscopy revealed that Optakoat was not as damaging to the diamond tool as the electroless nickel phosphorous. Numerous companies have measured the flatness and surface quality of deposits with various interferometers. Typical results indicated a surface roughness of 9 angstroms. After using conventional optical lapping techniques the surface roughness was reduced to 2-3 angstroms. This is a finer surface roughness than electroless nickel phosphorous can offer. Optakoat has a higher phosphorous content allowing the coating to be totally amorphous and increasing tool life. This leads to lower void volume and fewer defects in the coating. Additionally, it can be plated in excess of 0.030″ thick.



This deposit is totally amorphous improving diamond turning results

Optakoat Techdata Sheet


Notice the Stratification
(Laminar deposit)

EN often has discrete sites of crystalline structure





  • Customers’ report that in production runs Optakoat lasts 4 to 7 times longer than copper. 
  • Improved turn around time by eliminating several steps in the roll manufacturing process. 
  • This corrosion resistant material stops image distortion often experienced with plating of chrome or nickel over the diamond  turned copper surface. 
  • Multiple cuts can be made in Optakoat with no need for replating in between cuts. 
  • Users report longer diamond tool life when cutting Optakoat compared to electroless nickel.


The Top 10 Advantages of Optakoat 

  • Increased productivity:  Lens & Mold manufacturers report up to 70% less product fall out by using this glass-like alloy due to fewer pits, voids, occlusions or other structure.   
  • Extended diamond tool life compared to Electroless Nickel: Customers have typically reported 80 to 90% improvement with this totally amorphous non laminar coating.   
  • Great stability: Near neutral stress to slightly compressive gives Optakoat great stability.
  • Non- Magnetic:  OPTAKOAT has a phosphorous content unattainable with Electroless Nickel; it is totally amorphous & remains non-magnetic even when exposed to heat.
  • Hardness: 48 to 52 Rockwell C gives this deposit improved wear while maintaining excellent corrosion resistance.
  • The non laminar, high phosphorous content of Optakoat allows it to be easily applied to rollers for a flawless polished surface or for cutting a lenticular lens.
  • Unlike Copper, it does not require a flash of Nickel or Chrome to prevent corrosion thus eliminating cost, time, and image distortion.
  • Easily applied in thickness over 0.015″ allowing multiple cuts making changes inexpensive and quick.
  • Plated on ferrous or non-ferrous materials.
  • Preferred by the major manufacturers of diamond turning equipment:  Optakoat has been reported to produce better results than Electroless Nickel, which has a laminar deposit with discrete sites of crystalline structure.




Get the competitive edge by using the latest technology “OPTAKOAT”. The preferred metal coating used on plastic extrusion rollers for cutting lenticular lenses and dynamic imaging.


Optical Grade Electroless Nickel

Optical Grade EN –P is a high phosphorous, high build electroless nickel deposit, which is formulated specifically for the optics industry.  This coating is perfectly uniform and can be plated to thickness exceeding 0.026″.  Optic grade EN uses the best chemistries in a controlled atmosphere.  It is highly suitable for single point diamond turning.

The Top 10 Advantages of  “Optical Grade Electroless Nickel”

  • Uniform deposit thickness with no edge build-up.
  • Ability to hold tight tolerances within  + 0.0001″.
  • It covers hard to reach areas that are difficult or impossible to coat with other coatings including Optakoat.
  • Preferred by diamond turning and polishing professionals over standard high phosphorous Electroless Nickel deposits.
  • Used for corrosion resistance, hardness, and lubricity.
  • It can be applied on ferrous or non-ferrous materials.
  • Has a Rockwell C hardness of approximately 49.
  • Phosphorous content exceeding 11%.
  • Less void volume than standard Electroless Nickel.
  • Deposit can be plated in excess of 0.015″ thickness.

 en surfaceroughness


Phosphorous Content, wt. % 10.5-12                                                                 

Coefficient of Thermal Expansion, u/m°C 13-15                                              

Electrical Resistivity, microhm-cm 50-100                                                         

Hardness Knoop hardness 100g load, 3.0 mil deposit, steel As Plated 500-580

For more information on properties please click on our Techdata sheet: 
Optical Grade EN-P


Melting Point (eutectic) 1620°F

Thermal Conductivity, cal/cm/sec/°C 0.0105-0.0135

Magnetic Properties Non-magnetic

TM IR Gold & Nishield I & Nisheild II , for infrared reflectivity, specific IR emissivity reflectivity,  and other high reflective or high energy type applications.

Techmetals also does: Silver Plating, Gold Plating, Nickel plating, and other plating processes along with anodize, electro polish, medical coatings,  PVD Physical Vapor Deposition. Please see our main processes page to select other coating needs.