Summary for black colour phosphating Discussion
Black colour phosphating for high tensile fasteners is the focus of this thread. Soma Sundaram asks how to achieve a uniform black phosphate finish on AISI 4140 fasteners. Shankar Omprakash Khandelwal advises that hot manganese phosphating is the solution, saying it can produce a dark black phosphate coating and also improve lubrication for the fasteners. His reply is direct and confident, recommending that process rather than other options. The thread does not discuss process details, bath chemistry, or operating parameters, so the practical takeaway is limited to choosing hot manganese phosphating for the desired appearance and lubricity. A note in the source states that Mr. Shankar later passed away and is remembered as a knowledgeable contributor.
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.
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