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Finishing / Coatings

Finishing and Coatings

Mirror Buffed, Hot Dipped Galvanizing, Epoxy Coating, Electro Polished, Passivation, Teflon Coating, Oxidized, Zinc Plating, Chrome Plating


COATING/PLATING OPERATING TEMPERATURES
  • Cadmium Electroplating
    - High Service Temp: 608o F.
    - Low Service Temp: N/A; solid below 607o F.
  • Zinc or Zinc-Nickel Electroplating
    - High Service Temp: 788o F.
    - Low Service Temp: N/A; solid below 788o F.
  • Hot Dip Galvanizing
    - High Service Temp 800o F. 
    - Low Service Temp: N/A; solid below 800o
  • DuPont Teflon®  857G Series PTFE
    - High Service Temp: 500o F.
    - Low Service Temp: N/A
  • Xylan® 1400 Series PTFE
    - High Service Temp: 450o F. continuous, 550o F. intermittent
    - Low Service Temp: -320o F.
  • Xylar 2® Cermet
    - High Service Temp: up to 1,000o F.
    - Low Service Temp: N/A
  • Zinc Phosphate
    - Ambient Temperature
Finishing and Coatings
STANDARD COATING OPTIONS AVAILABLE
  • Xylan® PTFE
  • Xylar® Cermet
  • DuPont® 857G Series PTFE
  • SermaGard® 1105/1280 Cermet
  • Hot Dip Galvanizing
  • Mechanical Galvanizing (up to 1-1/2” dia., 5 lbs. wt., and/or 16” length per unit.)
  • Zinc Phosphate
STANDARD PLATING OPTIONS AVAILABLE
  • Cadmium
  • Zinc
  • Zinc-Nickel

Note: Xylan and Xylar are U.S. Patent & Trademark registered trade names of Whitford Worldwide Corp.

SermaGard is a trade name registered by Praxair, Inc. 


PTFE Coated Studs, Bolts and Nuts

PTFE coated fastener's provides great corrosion resistance, very low coefficient of friction, consistent tensioning and ease of installation and removal. Extensive testing and field use have proven that the future of coated fastener's lies with Fluoropolymer coatings. Previously hot dip, galvanized, cadium or zinc plated fastener's were considered the standard. But these coatings could not stand up to the corrosive atmospheres prevalent in many industries. The most widely used application is on B7 studs with 2H nuts.


Dramatic improvements in efficiency, life expectancy and corrosion resistance are claimed to be imparted to Nut and Bolt connectors by the application of a low friction PTFE coating. PTFE coated connectors have out-performed all others in aggressive any noticeable effect.


Technical Specifications

Use Temperatures

Working temp. range up to + 260°C

Corrosioin Resistance

Salt Spray (ASTM B117) up to 3,000 hrs (Nuts not frozen)

Pencil Hardness

5H – 6H (ASTM D3363-92A)

Kinetic Friction Coefficient

0.06 – 0.08

Thickness

Nominal 0.001" (1 mil)

Impact

160 in lb (ASTM D2794-93)

Adhesion

5B (ASTM D3359-95)

Elongation

35%-50%

Tensile Strength

4,000 psi

Operating Pressure

Up to 100,000 psi


PTFE coating on fastener’s will have a uniform thickness of 20 ± 5 microns to 45± 5 microns thick.


Why to Coat Bolts with PTFE Coatings?
  1. Cleaning and painting of bare steel bolts in the field is likely to be difficult, expensive, and in some cases, not feasible.
  2. The plain bolts, after stuffing in the holes, are expected to sit out in the weather for an extended period of time and get dried out and rusty, making correct tightening difficult or impossible.
  3. Release or retightening of the bolt within the foreseeable future is necessary.
  4. Due to its unique benefits, Fluoropolymer Coating has been applied to various types and grades of fasteners. The water works industry takes advantage of the superior corrosion resistance properties by coating Hex-head bolts for underground service. Stainless steel fasteners, used in many different industries, are coated for lubricity and anti-galling.
  5. Fluoropolymer coatings are extremely durable and not easily removed. However, during assembly of fasteners in the field, the coating can sometimes be damaged. With most other fluoropolymer coatings, this results in exposed bare metal that quickly begins to show corrosion and causes the coating to fail. Our metallic base coat ensures superior corrosion resistance and continues to provide protection even under the harshest conditions.