Plating & Finishes Guide
Plating & Finishes Guide
The finish on a fastener is its first line of defense against rust. The right coating depends on the environment, the base material, and how long the joint needs to last. Use this guide to match a finish to the job.
Plain / Uncoated
Bare steel with no surface treatment. The lowest-cost option, suited to dry indoor use, temporary work, or parts that will be painted or coated after install.
Zinc, Clear and Blue (Cr+3)
The most common general-purpose plating. A thin electroplated zinc layer with a trivalent (Cr+3) chromate that resists rust in indoor and light outdoor service.
Yellow Zinc (Cr+6 / Cr+3)
Zinc plating with a yellow chromate that adds a step up in corrosion resistance over clear zinc, often specified for automotive and equipment hardware.
Baked Zinc (Zinc Bake)
Zinc plating followed by a bake cycle that drives out absorbed hydrogen. This matters on hardened, high-strength bolts where hydrogen embrittlement is a risk.
Mechanical Zinc
Zinc deposited mechanically rather than electroplated. It coats hardened parts while sidestepping the embrittlement risk of standard electroplating.
Hot Dip Galvanized (HDG)
Parts are dipped in molten zinc for a thick, rugged barrier coating. This is the heavy-duty choice for outdoor, structural, and high-exposure applications.
Black Oxide and Thermal Black Oxide
A conversion coating that turns the surface black and adds mild corrosion resistance, usually with oil. Common on tooling, sockets, and indoor hardware for a low-glare finish.
Phosphate, Black and Gray (with Oil)
A phosphate conversion coating that holds oil or paint well and provides mild corrosion resistance. Standard on drywall, deck, and coated screws.
Specialty Exterior Coatings
Engineered proprietary coatings, including the Strong Shield coating on Strong-Point® outdoor screws, built for long-term corrosion resistance on exterior wood and decking.
| Finish | Corrosion Resistance | Typical Use | Notes |
|---|---|---|---|
| Plain / Uncoated | None | Indoor, dry, paint-over | Lowest cost |
| Zinc Clear/Blue (Cr+3) | Light | General indoor, light outdoor | Most common |
| Yellow Zinc | Light to moderate | Automotive, added coverage | Yellow tint |
| Baked / Mechanical Zinc | Light to moderate | Hardened, high-strength bolts | Reduces embrittlement |
| Hot Dip Galvanized | Heavy | Outdoor, structural, high-exposure | Thick, rugged coat |
| Black Oxide | Mild | Tooling, sockets, indoor | Black finish, low glare |
| Phosphate + Oil | Mild | Drywall, deck, coated screws | Holds oil and paint |
| Specialty Exterior | Heavy / long-term | Exterior wood and decking | Engineered coating |
Not Sure Which Finish Your Job Needs?
Call (714) 790-4042 or contact our team for help matching the right grade and finish to your application.
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