CURT 2-5/16 in. Chrome Trailer Ball 40039 — 12,000 lb Rated, Nickel‑Chrome Finish

CURT's 2-5/16-inch chrome trailer ball (model 40039) is a heavy-duty, VESC-tested tow ball rated to safely handle up to 12,000 pounds when used with compatible Class 5 hitch components.

This solid tow ball is built for demanding towing jobs where strength, fit and corrosion resistance matter. Hot-forged, heat-treated steel and a nickel-chrome finish give the CURT 40039 the durability needed for hauling dump trailers, toy haulers, dual-axle utility trailers, larger RVs and similar receiver-style trailers. Designed with standard dimensions, proven fasteners and VESC testing, it’s engineered to integrate with existing Class 5 setups while protecting against the elements.

How does this trailer ball deliver the strength I need for heavy loads?

The CURT 40039 is manufactured from hot-forged, heat-treated steel to maximize tensile strength and fatigue resistance under load. Its 12,000 lb gross trailer weight rating aligns it for heavier towing tasks when paired with matching hitch and vehicle capacities.

• 12,000 lb gross trailer weight (GTW) rating
• Hot-forged, heat-treated steel construction for high strength
• Tested to U.S. VESC specifications for consistent performance

Will this fit my coupler and hitch mount correctly?

The ball uses the industry-standard 2-5/16-inch diameter to match most 2-5/16-inch couplers, and the 1-inch shank diameter with a 2-1/4-inch shank length fits securely into compatible Class 5 ball mounts. Fine threads and supplied hardware ensure a snug, reliable installation when torqued to specification.

• 2-5/16" ball diameter for standard coupler compatibility
• 1" shank diameter, 2-1/4" shank length for secure mounting
• Includes zinc-plated hex nut and helical lock washer; 250 lb-ft torque required

How does the finish protect against weather and wear?

The CURT 40039 uses a nickel-chrome plating that creates a barrier to moisture, dirt and surface rust, extending service life and keeping the ball surface smooth for better coupler contact. Regular inspection and basic maintenance will preserve the finish and functionality through many towing seasons.

• Nickel-chrome plated surface for corrosion resistance
• Smooth, polished ball surface reduces wear on coupler components
• Simple cleaning and inspection prevent premature corrosion

What installation and safety checks should I follow before towing?

Secure the ball using the provided hex nut and helical lock washer, tightening to the recommended 250 lb-ft torque to prevent loosening under load. Always verify the lowest-rated component in your towing setup—vehicle, hitch, ball mount or trailer—to avoid exceeding safe limits.

• Use supplied zinc-plated nut and helical lock washer for secure install
• Tighten to 250 lb.-ft. torque for proper clamping force
• Confirm all towing components meet or exceed required ratings before use

Who is this for? The CURT 40039 2-5/16" chrome trailer ball is aimed at drivers who tow heavier trailers and need a rugged, industry-standard ball that pairs with Class 5 hitch systems. It’s a practical choice for contractors, farmers, RV owners, marina operators and anyone who regularly tows multi-axle utility trailers, toy haulers, dump trailers or larger recreational trailers—so long as the vehicle and hitch are rated for the same or greater load.