Carriage Bolts for Outdoor Use: What You Need to Know
Carriage bolts are widely used in outdoor structures such as fences, decks, playground equipment, and steel-wood connections. When exposed to rain, humidity, or salt air for long periods, the material and surface treatment of carriage bolts directly affect corrosion resistance and service life.
As a professional carriage bolt manufacturer, Xinchi is proud to introduce the differences between stainless steel grades and galvanized coatings, hoping it could help buyers choose the right carriage bolts for outdoor use and avoid premature rust or failure.
Stainless Steel Carriage Bolts: 304 vs 316 for Outdoor Applications
Stainless steel is a common choice for outdoor carriage bolts due to its natural corrosion resistance. Among available options, 304 and 316 stainless steel are the most frequently used.
304 stainless steel carriage bolts offer good resistance to general corrosion and are suitable for normal outdoor environments with moderate humidity. They are commonly used in residential outdoor furniture, garden structures, and general construction, where exposure conditions are not extreme.
316 stainless steel carriage bolts contain molybdenum, which significantly improves resistance to chlorides and salt corrosion. For high-humidity areas, coastal regions, or environments exposed to seawater or chemical vapors, 316 stainless steel carriage bolts provide longer service life and better stability compared to 304.
Galvanized Carriage Bolts vs Hot-Dip Galvanized Carriage Bolts
For carbon steel carriage bolts, surface treatment plays a key role in corrosion protection. Zinc plating and hot-dip galvanizing are two common options, but their performance outdoors differs greatly.
Zinc-plated carriage bolts have a thinner coating and offer basic corrosion resistance. They are suitable for short-term outdoor use or semi-outdoor environments where direct exposure to rain and moisture is limited.
Hot-dip galvanized carriage bolts feature a much thicker zinc layer formed by immersing the bolt in molten zinc. This coating provides stronger and longer-lasting protection against rust, making hot-dip galvanized carriage bolts a better choice for long-term outdoor structures, fences, and infrastructure projects.
Choosing the Right Carriage Bolts for High-Humidity and Coastal Environments
In high-humidity or coastal environments, selecting the correct carriage bolts for outdoor use is especially important. Salt spray, moisture, and temperature fluctuations can accelerate corrosion if the material is not suitable.
For coastal or marine-related projects, 316 stainless steel carriage bolts are generally recommended due to their superior resistance to salt corrosion. In non-marine but highly humid environments, hot-dip galvanized carriage bolts can also provide reliable performance when cost control is a consideration.
Evaluating the installation environment, expected service life, and maintenance conditions helps ensure the chosen carriage bolts meet both performance and budget requirements.
Why Choose Xinchi for Outdoor Carriage Bolts
Xinchi Fasteners is a professional manufacturer of carriage bolts for outdoor and industrial applications. The factory was established in 2007 and is equipped with a total of 102 cold heading machines, achieving a daily output of over 10 million pieces.
The newly completed factory covers an area of 30,000 square meters with two six-story buildings, supporting stable production capacity and consistent quality control. As a trusted fastener supplier, we offer nuts, screws, bolts, rivets, and washers, etc. Xinchi supplies fasteners in various materials and surface treatments to meet different outdoor usage requirements.