Hotop 8 Pcs 304 Stainless Steel Square U-Bolt, 1/2 D x 3 1/16 W x 5 5/16 Inch, Corrosion-Resistant Kit with Nuts & Washers

This complete set contains eight square U-bolts plus matching stainless flat washers, lock washers, and nylon-lock nuts so you get everything required to fasten rectangular tubing and wooden beams. Machined from 304 stainless steel, the components resist rust and hold steady in marine and humid environments. The bolts are sized to fit 3 x 3 inch sections and include 2-1/2 inches of thread for flexible clamp thickness.

What sizes and parts are included in the kit?

The pack includes 8 square U-bolts sized 1/2 D x 3 1/16 W x 5 5/16 L, each with 2-1/2 inches of thread. Also included are 16 stainless flat washers, 16 stainless nylon-lock nuts, and 16 lock washers—matching quantities allow secure fastening on both ends where needed.

• U-bolt dimension: 1/2" diameter, 3 1/16" inside width, 5 5/16" overall length
• Thread length: 2-1/2" for varied clamp thicknesses
• Hardware: 16 flat washers, 16 lock washers, 16 nylon-lock nuts
• Quantity: 8 complete U-bolt assemblies

How durable are these U-bolts in outdoor or marine use?

Made from 304 stainless steel, these U-bolts stand up to moisture, salt spray, and most common corrosive environments. While no metal is invulnerable, 304 stainless offers excellent general-purpose corrosion resistance for trailers, docks, and outdoor equipment.

• 304 stainless construction reduces rust and pitting
• Nylon-lock nuts help prevent loosening under vibration
• Suitable for rainy, humid, and seaside conditions
• Each bolt rated for typical clamp loads in general fastening tasks

How do I select and install the right square U-bolt for my project?

Choose the U-bolt when the tube or beam measures roughly 3 x 3 inches inside the U shape. Mark and drill matching holes into the parts to be clamped, place the U-bolt around the beam, then secure with washers and nylon-lock nuts using a hand wrench or socket—avoid impact drivers to protect threads and the nylon insert.

• Verify beam/tube dimensions before ordering
• Drill clearance holes aligned with U-bolt legs
• Tighten nuts using a hand wrench or socket ratchet
• Do not use high-speed impact tools on nylon-lock nuts

Where are these square U-bolts typically used?

They are commonly used to fasten or secure square and rectangular timber or metal members in vehicle trailers, marine trailers, plumbing runs, and industrial frames. The square profile keeps the bolt stable against flat surfaces and resists rotation in the clamp.

• Boat and sailboat trailer mounting brackets
• Securing square tubing in rack and frame assemblies
• Plumbing and conduit supports on rectangular runs
• General-purpose fastening for outdoor hardware

Who is this for: This Hotop kit is aimed at DIYers, repair shops, trailer owners, and small fabricators who need a ready assortment of high-quality square U-bolts and matching hardware. If you work on boat trailers, outdoor racks, or any project with 3 x 3 inch square members and want corrosion-resistant fasteners with reliable locking nuts, this set supplies the fasteners and extras to complete multiple installations.