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Round Zinc Plated U-Bolt 3" x 9/16" Diameter x 7" Long Fine Thread Grade 5 (UB-R303-ZP)

$11.99
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Trailer Axle U-Bolt / Suspension Hardware

Round Zinc Plated U-Bolt 3" x 9/16" Diameter x 7" Long Fine Thread Grade 5

Silver zinc plated metal round U-bolt for compatible trailer axle and suspension applications where a 3" inside width, 9/16" diameter, 7" long U-bolt is required.

SKU: UB-R303-ZP 3" x 9/16" Dia. x 7" Long Fine Thread / SAE Grade 5

Key Measurements & Specs

Specification Detail
SKU UB-R303-ZP
Product Type Round trailer axle U-bolt
Size 3" x 9/16" diameter x 7" long
Thread Type Fine thread
Threads Per Inch 18 TPI
Grade SAE Grade 5
Material / Finish Metal, zinc plated
Color Silver
Quantity Included 1 U-bolt

Fitment / Application

Category Details
System Trailer axle and suspension hardware
Application Reference Fits compatible 7000# applications where measurements and hardware match
Matching Thread 9/16"-18 fine thread
Related Hardware Reference UBN-9C / TP-4 reference where correct for the application
Fitment Method Verify axle tube size, U-bolt width, bolt diameter, length, plate fitment, and nut thread before ordering

Top Features

Feature Buyer Benefit
Zinc Plated Finish Silver finish provides corrosion-resistant surface protection for trailer hardware use
9/16"-18 Fine Thread Matches compatible fine-thread nuts and suspension hardware
SAE Grade 5 Built for heavier-duty trailer suspension fastening applications where Grade 5 hardware is specified
3" x 7" Size Useful for compatible axle tube and U-bolt plate setups requiring this measurement

Overview

This listing is for one round zinc plated U-bolt, SKU UB-R303-ZP. The U-bolt measures 3" x 9/16" diameter x 7" long and uses 9/16"-18 fine thread. It is SAE Grade 5 hardware with a silver zinc plated finish for compatible trailer axle and suspension applications.

R&P Service Insight

U-bolts must be matched by measurement and thread, not by appearance alone. Before replacing axle hardware, confirm the complete suspension stack matches this 3" width, 9/16" diameter, 7" length, and 18 TPI thread requirement.

  • Measure First: Confirm U-bolt width, diameter, and overall length before ordering.
  • Thread Match: This U-bolt uses 9/16"-18 fine thread.
  • Hardware Match: Confirm the nut and plate match the U-bolt size and thread before installation.

R&P Knowledge Hub

Compatibility: Use for compatible 7000# trailer axle applications where the existing U-bolt dimensions, thread, and related hardware match.

Vehicle / System Fit: Trailer axle and suspension hardware applications using a round 3" x 9/16" diameter x 7" long U-bolt.

Installation Notes: Verify axle tube size, U-bolt plate, nut thread, and length before installation. Replace worn or mismatched suspension hardware as needed.

Performance Insight: Correct U-bolt size and thread engagement are critical for proper axle clamping and suspension hardware alignment.

Brand & Fitment Note

Selling Brand: R&P Carriages

Application Reference: 7000# application references are fitment guides only. Final fit depends on matching the U-bolt measurements and related suspension hardware.

What This Means: This listing is for one R&P Carriages round zinc plated U-bolt, not a complete U-bolt kit unless specifically stated.

Before Ordering: Verify measurements, thread pitch, axle tube size, plate compatibility, nut compatibility, and included components before installation.

R&P Repair Insight

When servicing trailer suspension hardware, U-bolts should be selected by exact measurement and thread specification. A mismatch in diameter, length, thread pitch, or plate fit can prevent proper installation.

  • Width Check: Confirm the 3" U-bolt width matches the axle tube and plate setup.
  • Thread Check: Confirm the mating nuts are 9/16"-18 fine thread.
  • Length Check: Confirm the 7" length provides the correct fit for the spring stack and plate arrangement.

Features

Round U-Bolt Design

Designed for compatible round trailer axle and suspension fastening applications where this size is required.

9/16"-18 Fine Thread

Fine-thread 9/16" diameter hardware with 18 threads per inch for matching compatible nuts.

SAE Grade 5 Hardware

Grade 5 specification for compatible trailer suspension applications requiring this hardware grade.

Silver Zinc Plated Finish

Zinc plated metal construction with a silver finish for clean appearance and surface protection.

Included Components

Quantity Item
1 Round zinc plated U-bolt, 3" x 9/16" diameter x 7" long, 9/16"-18 fine thread
Not Included Nuts, plates, washers, and additional suspension hardware unless separately selected or stated
Important Fitment Note: Verify all measurements, thread pitch, axle tube size, U-bolt plate fitment, nut compatibility, and included components before installation. This listing is for one U-bolt only unless otherwise stated.
UB-R303-ZP round zinc plated U bolt, 3 inch 9/16 diameter 7 inch long U bolt, 9/16-18 fine thread U bolt, SAE Grade 5 trailer axle U bolt, silver zinc plated metal U bolt, 7000 lb trailer axle U bolt, UBN-9C compatible thread reference, TP-4 trailer suspension hardware reference, R&P Carriages trailer axle suspension hardware