GMW GMW15823 PDF

This specification covers basic requirements for a corrosion resistant electrolytic coating of the copper-nickelchromium type intended primarily for bulk processed small parts made from carbon steel and brass for parts such as bolts, tapping screws, thread rolling screws, self drilling tapping screws, nuts/J-nuts, and, particularly as a lower-cost substitute for nickel-chromium plated stainless steel screws.

This finish provides a shiny silver luster for highly visible exterior and interior parts. This is a premium finish, where customer perception of the shine and quality of these parts, often described as jewelry, is important. Also, relative to other fastener finishes, this finish is not galvanically attacked and quickly consumed when coupled to stainless steel or to other chrome-plated parts.

Note: Certain details, such as luster, are intended to be covered on drawings, purchase orders, and/or by agreement between individual purchaser, engineer, and supplier.

Note: When visibility makes corrosion resistance critical, a higher-performance plating system (GMW14672-A, B) or stainless steel substrate should be considered.

Material Description. Use of this finish on threaded surface and/or bearing surface of joints could affect the torque-tension relationship. It is recommended that a torque-tension study of the fastener joint be performed before releasing this finish on a new application. It is an ideal surface treatment for very small and minute parts. These serve as excellent candidates for this finish.

If there can be no marks on the finished fastener due to high visibility, individual racking of parts for plating may be needed.

Symbols. Not applicable.

Typical Applications. Typical applications are as follows:

• Carriage bolt for bumper attachment 

• Door striker bolts

• License plate attachments 

• Exterior cosmetic aesthetic bolt

• SEMS bolts 

• Flow bolts 

• Wheel nuts

• Flat lock fasteners 

• Clips/attachments for Chromium (Cr) plated parts

• All very small and minute parts

Use of this finish (or any other copper-nickel-chrome plating systems) against bare or painted aluminum is not recommended.

Remarks. Not applicable.