SURFACE FINISHES

Standard Finishes:

·         Clear Iridite on aluminum.

·         Clear Zinc on Steel. 

Custom Finishes

Chemical Film per MIL-C-5541, Class 1A for aluminum parts requiring corrosion protection.  Color: Yellow, unless specified clear.

Chemical Film per MIL-C-5541, Class 3 for aluminum parts requiring low electrical resistance.  Color:  yellow, unless specified clear.

Chromeric Anodize per MIL-A-8625, Type I, Class 1* for aluminum parts that are welded or where extrapment is possible.  Color:  clear-metallic gray. *Specify Class 2 for dyed colors.

Sulfuric Anodize per MIL-A-8625, Type II, Class 1* for aluminum parts where no overlapping surfaces or pockets are present.  *Specify Class 2 for dyed colors.

Hard Anodize per MIL-A-8625, Type III, Class 1* for aluminum parts requiring durable wear surfaces.  Thickness is .003 normally.  *Specify Class 2 for dyed colors.

Bright Tin Plate per MIL-T-10727, min thickness of .003 for copper parts requiring corrosion protection or galvanic compatibility.

Electroless Nickle Plate per MIL-C-26074, Class 1, Grade A for steel and copper parts requiring corrosion protection.

Zinc Plate per ASTM B633, Type III, Class SC3 for steel parts requiring corrosion protection.  Color is clear and bright in appearance.

General

The criteria provided in this section relates to visual appearance of parts which have been plated, painted, or both. Of major importance are those surfaces that will be highly visible on critical surfaces; somewhat less stringent requirements are imposed in other areas. This section is to be used for in-process activities only; assessment of received materials shall be performed using appropriate Procurement specifications, and/or detailed Incoming Inspection criteria and techniques.

Major Defect    The type of defect that:

Is clearly visible in an un-highlighted condition

Exposes bare metals or substrate surface

Exceeds stated criteria or other specific requirements

Is easily felt with a fingernail (dents or scratches)

Would leave a greater flaw if removed or reworked (inclusion)

Is non-uniform surface finish (shaded appearance)

Would cause corrosion, rust, peeling, delamination, etc. 

Minor defect    The type of defect that:

Is clearly not visible in an un-highlighted condition or when assembled in an assembly

Barely felt with a fingernail

Tends to fade out or blend in with surrounding surface

Would be concealed during next process or assembly level (label, paint or other finishing process).

Normal Viewing Plane   

The normal viewing plane is defined as the view obtained when observing the assembled unit top, front, sides, and back exterior surfaces in a plane perpendicular to these surfaces.  The part will not be rotated except to eliminate any glare from surrounding light that tends to produce a “highlighted” condition.