The authoritative public forum
  for Metal Finishing since 1989
-----

Oil Field Tooling that uses Hard Chrome Applications

2002

Oil Field Tooling: Chrome Plating applications

I'm trying to educate myself on different types of applications and parts (names of parts)that require hard chrome.....example, Mud Motor screws......any type of machined part in this industry that may benefit from hard chrome applications.........

Thank you,

Greg Fotre
- Clarksville, Tennessee

The scope of parts requiring hard chrome plating is huge. Hard Chrome as you probably know is a very hard engineering finish used in a number of different industries.

Parts such as molds, hydraulic shafts and piston rods, rings, gears, rails, guides as well as thousands of other types of parts are plated every day with hard chrome. Hard Chrome greatly increases the usable life of parts in applications where wear is a problem. In sufficient thicknesses, Hard Chrome also increases the corrosion resistance. It can be applied with just a flash (usually .0001-.0002") or as thick as .050-.075". The thicker deposits require grinding after applications of several thousandths of chrome to ensure concentricity, flatness and to remove nodules that may occur in the deposit.

Hope this helps!

Daryl Spindler, CEF
decorative nickel-chrome plating - Greenbrier, Tennessee
2002

In oil tool products there is a lot of considerations to look at, and as far as life of product and type and thickness's etc is the projected quantities of sulfide in the well, If there is "high" sulfides in the well the crack pattern the Hard Chrome will actually be undermined very quickly, a nickel underlay is put on under the chrome, Depending on type of service, Might be Electroless Nickel, sulphate Nickel, Watts Nickel Hope this might help a little.

Chris Snyder
plater - Charlotte, North Carolina
2003

---

2003

To Mr. Chris Snyder,

How do you activate EN for subsequent hard chromium? This has been one of our headaches. We have used Woods but the results are unpredictable; when parts are small, room-temp-Watts bath cools them too much for the chrome. When they are massive the parts dry and the thin Woods passivates quickly so that we have found it to be quite tricky.

Also,
1- Do you rinse EN before going to the Watts? At what pH and temp?
2- Do you use live entry to chrome bath, or let it stand to gain bath's temp?
3- Do you ramp up or give it an initial kick?
4- What chrome chemistry are you using, mixed, fluoride?

Thanks,

Guillermo Marrufo
Monterrey, NL, Mexico

---

To answer some questions:

1.Yes you need to rinse E/N on large parts mask as needed hand scrub with pumice and then acid salt activator when put parts into Chrome do not let dry
2. Let part(s) warm to temperature would not reverse in chrome
3. Would strike hard and ramp down to running amps
4. I like conv. Chrome 100:1 for hard chrome but mostly for the reason of masking and no etching of unplated areas

Chris Snyder
- Charlotte, North Carolina
2003