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How to achieve black colour phosphating

Q. Dear Sir,

We are required to achieve the Uniform Black colour Phosphating in High Tensile Fasteners (Material AISI:4140).

Kindly give your suggestion.

Soma sundaram
Phosphating shop employee - Chennai, India
January 30, 2009

A. Dear friend,

Try Hot manganese phosphating, that's your solution, You would not only achieve dark black phosphating, but also support lubrication to the fasteners.

Do it now, don't look for options.

ALL THE BEST.

Shankar Omprakash Khandelwal [deceased]
- Coimbatore, TAMILNADU, INDIA
It is our sad duty to pass along the information that the knowledgeable Mr.Shankar was lost to Covid/Corona.
He was awarded with honorable medal by then Indian president Ms. Pratibha Patil. R.I.P.

adv.
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