Stainless steel nails make more sense than ever in today’s world of acid rain, pressure-treated building materials, and tight economics. Unlike galvanized and coated nails, stainless steel’s corrosion resistance is uniform through and through, and it offers protection that isn’t compromised by installation procedures that will crack, chip, or abrade coated or galvanized nails.
Naturally, stainless steel is most often used in projects where exposure to weather is most severe. However, even in mild environments, the tannic acid levels in Redwood and Western Red Cedar will rapidly cause staining with most coated nails, and even galvanized nails will eventually succumb and leave ugly stains. Pressure-treated lumber also causes deterioration of galvanized nails as the zinc coating combines chemically with the copper salts used in the pressure-treating process.
Stainless steel nails can help avoid the need to replace siding or decking every few years because of unsightly discoloration, or fastener failure. While stainless steel nails are obviously more expensive than ordinary galvanized nails, the difference is small when considering the total cost of construction, and the security in knowing that the job is done right the first time.
Why Two Different Grades?
The reason is simple: common 304 stainless offers significant corrosion protection in all but the harshest environments. For applications exposed to large concentrations of salt such as seaside docks, decks, or buildings, 316 stainless offers more protection through its increased nickel content.
What About Strength?
Stainless steel nails are STRONG! Wire tensile strength ranges from 125,000 to 145,000 psi; the ultimate lateral strength of stainless nails is about 20% higher than that of ordinary plain steel nails; stiffness is about equal.
About the Shank Style
“Ring-Shank” nails are most popular because they offer superior resistance to withdrawal. Annular rings on the shank act like one-way barbs as the nail enters the wood, locking it in securely. “Ring-Shank” nails are not suitable for use where substantial shear, racking, or lateral loads are present.
Note: Pilot holes are rarely needed with stainless steel nails, any more than they are needed with common steel or galvanized nails. However, you can eliminate splitting wood or bending nails by predrilling, using this table as a guide. Pilot holes should be 3/4 of the length of the nail used, for best results.