Product Overview
Wheel Diameter and Width : 12 x 4
Bolt Pattern : 5 on 4.5"
Center Hole : 3.19"
Load Capacity : 1,520lbs per wheel (Heavy Duty)
Fits Tire Size(s) : 4.80x12, 5.30x12, ST145/R12
Hot Dipped Galvanized Steel
Recommended PSI : Limited to valve stem
This style wheel is commonly known as a mod wheel and is often used on boat trailers, utility trailers as well as small-medium trailers.
Hot Dipped Galvanization is the process by which a steel part is physically dipped into a molten bath of zinc at a temperature of around 840°F. The zinc adheres to the steel part (in this case a trailer wheel) and completely coats the steel trailer wheel. The zinc then reacts with oxygen to form zinc oxide, and then reacts with carbon dioxide to form zinc carbonate. The result is a dull grey, anti-corrosive finish that protects the trailer rim from rust and corrosion. Trailer Wheels are commonly galvanized as it is more cost effective than stainless steel.
Galvanization forms a protective layer between the steel rim and the environment. Zinc is an electro-negative metal in comparison to the steel. This is an important characteristic of galvanized rims, because in the event that the galvanized surface is damaged and the steel rim is exposed; the coating can continue to protect the wheel up to 5mm in diameter through galvanic corrosion. Damaged areas greater than 5mm are not protected as much because the electron transfer rate decreases.
The Hot-Dipped Galvanization Process:
- The Steel Rim is cleaned with a solution that removes any grease, dirt or oil. This solution is then rinsed off
- The steel wheel is pickled in an acidic solution to remove mill scale & rinsed
- A Flux is applied to the steel that inhibits any oxidation that may occur to the raw steel as it is exposed to oxygen
- The rim is then dipped into the bath of molten zinc until the temperature of the wheel matches that of the molten zinc bath
- The steel rim is cooled in a quench tank to bring the temperature back down in a controlled manner
