Missing Chrome Inside a Button
Q. Hello Mr. Taylor, we buy buttons for shift knobs/automotive industry,
and noticed some areas missing chrome inside not visible to the user
aproximately 1/2 inch away from A surface. Could that represent a risk of
durability of the part? Or is this normal to get given the deepness of the
Thanks in advance
A. What you're referring to is called "throw in". I'm not aware of your
specific acceptance criteria for plating, but if you are referring to
evidence of a plated coating and the depth or distance it coats into holes
and recesses, there is a rule of thumb. If no other requirements, plating
should be present at least to a depth equal to 1/2 the diameter of the hole.
If the hole was .25 in diameter, the plating should throw into the hole at
least 1/8th of an inch deep from the edge, unless otherwise specified.
Irregardless, in my opinion, as long as there is 100% coating coverage on
the exterior, and little or no plating coverage inside the hole, the risk of
durability is fairly low. The risk of corrosion will be slightly greater if
the plated coating terminates at the edge of a hole and would increase if
the termination of the plated coating is outside a hole.