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U-Bolts

U-Bolts

We maintain a complete stock of leaf spring U-bolts for all types of trucks and trailers. Don’t see the size you need? We bend U-bolts for custom applications. We only use cold-drawn, stress relieved, micro-alloyed, 1541 modified steel in our U-bolt kits.

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Found 386 Matching Products
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Grid List
v
SKU 8-14185K
$68.49
Leaf Spring U Bolt Kit | Semi-Round | Grade 8 | 7/8 x 3 x 21-1/8 | GMC

Semi-Round U-Bolt Kit with 2 Grade 8 U-Bolts that are 7/8 inches in diameter, 3 inches wide and 21-1...   Details

Typically ships in 1 business day.
  • Application:GMC
  • Rod Length:46"
  • Diameter (A):7/8"
  • Bend:Semi-Round
  • Grade:8
  • Width (B):3"
  • Length (C):21-1/8"
  • Note:Generic Images
  • MPN: 8-14185K
SKU 361-388
$46.11
Leaf Spring U Bolt Kit | Square | Grade 8 | 5/8 x 2-1/2 x 16-5/8

Square U-Bolt Kit with 2 Grade 8 U-bolts that are 5/8 inches in diameter, 2-1/2 inches wide and 16-5...   Details

Typically ships in 3 to 4 business days.
  • Diameter (A):5/8"
  • Bend:Square
  • Grade:8
  • Width (B):2-1/2"
  • Length (C):16-5/8"
  • Note:Generic Images
  • MPN: 361-388
SKU 8-1002K
$24.11
Leaf Spring U Bolt Kit | Square | Grade 8 | 5/8 x 2-9/16 x 6-3/8

Square U-Bolt Kit with 2 Grade 8 U-Bolts that are 5/8 inches in diameter, 2-9/16 inches wide and 6-3...   Details

2 In Stock
  • Rod Length:16"
  • Diameter (A):5/8"
  • Bend:Square
  • Corner Radius:0.250
  • Grade:8
  • Width (B):2-9/16"
  • Length (C):6-3/8"
  • Note:Generic Images
  • MPN: 8-1002K
SKU 8-1458K
$62.30
Leaf Spring U Bolt Kit | Square | Grade 8 | 7/8 x 3 x 18

Square U-Bolt Kit with 2 Grade 8 U-Bolts that are 7/8 inches in diameter, 3 inches wide and 18 inche...   Details

Typically ships in 1 business day.
  • Rod Length:40"
  • Diameter (A):7/8"
  • Bend:Square
  • Corner Radius:0.500
  • Grade:8
  • Width (B):3"
  • Length (C):18"
  • Note:Generic Images
  • MPN: 8-1458K
SKU 361-449
$48.69
Leaf Spring U Bolt Kit | Square | Grade 8 | 3/4 x 3 x 15-3/8

Square U-Bolt Kit with 2 Grade 8 U-bolts that are 3/4 inches in diameter, 3 inches wide and 15-13/8 ...   Details

Typically ships in 3 to 4 business days.
  • Diameter (A):3/4"
  • Bend:Square
  • Grade:8
  • Width (B):3"
  • Length (C):15-3/8"
  • Note:Generic Images
  • MPN: 361-449
SKU 361-400
$24.94
Leaf Spring U Bolt Kit | Round | Grade 8 | 5/8 x 2-7/8 x 6-3/4

Round U-Bolt Kit with 2 Grade 8 U-bolts that are 5/8 inches in diameter, 2-7/8 inches wide and 6-3/4...   Details

Typically ships in 3 to 4 business days.
  • Diameter (A):5/8"
  • Bend:Round
  • Grade:8
  • Width (B):2-7/8"
  • Length (C):6-3/4"
  • Note:Generic Images
  • MPN: 361-400
SKU 8-12255K
$41.79
Leaf Spring U Bolt Kit | Semi-Round | Grade 8 | 3/4 x 4 x 13 | Ford

Semi-Round U-Bolt Kit with 2 Grade 8 U-Bolts that are 3/4 inches in diameter, 4 inches wide and 13 i...   Details

Typically ships in 1 business day.
  • Application:Ford
  • Rod Length:30"
  • Diameter (A):3/4"
  • Bend:Semi-Round
  • Grade:8
  • Width (B):4"
  • Length (C):13"
  • Note:Generic Images
  • MPN: 8-12255K
SKU 8-1022-34K
$31.48
U-Bolt Kit | Round | 5/8 x 3 x 8-5/8, 5/8 x 3-1/2 x 9-1/2 Inch

Round U-Bolt Kit with 2 Grade 8 U-Bolts.   Details

Typically ships in 1 business day.
  • Rod Length:20"
  • Diameter (A):5/8"
  • Bend:Round
  • Grade:8
  • Width (B):3"
  • Length (C):8-5/8"
  • Note:Includes (1) U-Bolt 8-1022K: 5/8 x 3 x 8-5/8 and (1) U-Bolt 8-1034K: 5/8 x 3-1/2 x 9-1/2
  • MPN: 8-1022-34K
SKU 8-1256K
$40.68
Leaf Spring U Bolt Kit | Round | Grade 8 | 3/4 x 5 x 12

Round U-Bolt Kit with 2 Grade 8 U-Bolts that are 3/4 inches in diameter, 5 inches wide and 12 inches...   Details

Typically ships in 1 business day.
  • Rod Length:28"
  • Diameter (A):3/4"
  • Bend:Round
  • Grade:8
  • Width (B):5"
  • Length (C):12"
  • Note:Generic Images
  • MPN: 8-1256K
SKU 361-200
$37.44
Leaf Spring U Bolt Kit | Square | Grade 8 | 3/4 x 4 x 12-7/8

Square U-Bolt Kit with 2 Grade 8 U-bolts that are 3/4 inches in diameter, 4 inches wide and 12-7/8 i...   Details

Typically ships in 3 to 4 business days.
  • Diameter (A):3/4"
  • Bend:Square
  • Grade:8
  • Width (B):4"
  • Length (C):12-7/8"
  • Note:Generic Images
  • MPN: 361-200
SKU 361-444
$27.44
Leaf Spring U Bolt Kit | Semi-Round | Grade 5 | 1/2 x 2-9/16 x 10-7/8

Semi-Round U-Bolt Kit with 2 Grade 5 U-bolts that are 1/2 inches in diameter, 2-9/16 inches wide and...   Details

Typically ships in 3 to 4 business days.
  • Diameter (A):1/2"
  • Bend:Semi-Round
  • Grade:5
  • Width (B):2-9/16"
  • Length (C):10-7/8"
  • Note:Generic Images
  • MPN: 361-444
SKU 8-1257K
$41.79
Leaf Spring U Bolt Kit | Round | Grade 8 | 3/4 x 5 x 13

Round U-Bolt Kit with 2 Grade 8 U-Bolts that are 3/4 inches in diameter, 5 inches wide and 13 inches...   Details

Typically ships in 1 business day.
  • Rod Length:30"
  • Diameter (A):3/4"
  • Bend:Round
  • Grade:8
  • Width (B):5"
  • Length (C):13"
  • Note:Generic Images
  • MPN: 8-1257K

How do I measure a Leaf Spring U-Bolt?

Truck and trailer leaf spring u-bolts come in all different dimensions, widths and lengths and many are custom bent, so getting your measurements correct is key.

Here is a video on how to measure U-Bolts. How To Measure Leaf Spring U-Bolts
type of ubolt bends

Step 1: Type of Bend

The typical U-bolt is rounded just like the letter "U". Yet there are a number of different of U-bolt types. The three primary types of bends are round, square and semi-round. Your vehicle's leaf spring suspension style and the shape of its parts will determine which type of bend is necessary. We do stock other types of u-bolts like Forged Bend, but they are not as common.

how to measure a u-bolt

Step 2: Rod Diameter

After you determine the bend you need, measure the rod diameter (A). The diameter can easily be measured with a wrench.

The socket sizes below will help to determine your rod size.

  • 11/16 socket = 7/16” diameter rod
  • 3/4 socket = 1/2” diameter rod
  • 13/16, 7/8 or 22mm socket = 9/16” diameter rod
  • 15/16 socket = 5/8” diameter rod
  • 1-1/16 or 1-1/8 socket = 3/4” diameter rod
  • 1-5/16 socket = 7/8” diameter rod

Step 3: Length and Width

Measure the inside width (B) and the length (C) of the U-bolt legs as well. With this information in-hand, you will be well on your way to a quick and easy U-bolt installation.

What is a Leaf Spring U-Bolt and What Does It Do?

leaf spring ubolt installed

You are not alone if you haven't heard of a leaf spring U-bolt. Most people have no idea what type of function this little part plays in the average truck's operation. Truck U-bolts are used within vehicle suspension to connect leaf springs. They offer the force necessary to clamp the leaf spring along with its related components to one another, providing a lasting attachment to the axle.

When installed correctly, U-Bolts help eliminate spring flexing and allow a vehicle to maintain its ride height and handling. A firm connection between the leaf spring and the axle seat offsets the horizontal pressure on the center bolt. If this connection is loose, the increased horizontal pressure can cause the center bolt to break, leading to leaf spring failure.

Tight U-bolts help prevent broken leaf springs. For more information, read this article on broken leaf springs and what causes leaf springs to fail. You can do your truck an enormous favor by having your leaf spring U-bolts inspected during your next service maintenance appointment.

Why Replace Your Truck or Trailer U-Bolts

Ordinary vehicle use wear and tear causes U-Bolts to stretch and lose shape or even loosen. The threads wear as they contact the Hi-Nuts. Weather takes its toll and can cause them to rust. As aging occurs, the U-bolt slowly loses its clamping function, increasing the likelihood of leaf spring failure.

Replacing U-Bolts ensures they provide adequate clamping force that safeguards against spring failure and other harm to the suspension. It is an essential component of doing a complete repair.

If you don't replace the U-Bolts when installing leaf springs, you void the manufacturer's warranty.

Most at-home mechanics can replace leaf spring U-bolts without trouble. We have a few tips to help you along the way. Read more.

Can't find the right U-Bolts for your application? We stock grade 5 and grade 8 steel threaded rods and can custom bend to your requirements.

Need Help? Call 1-800-358-4751 Today!

U-Bolts Reviews

Out of 15 reviews, the average customer rating for U-Bolts: 4.9 out of 5.

u-bolt kit 5-0995k reviewer
U-Bolts - L&H 5-0995K Rating: 5 Stars

Yes

very pleased with my purchace and michigan spring

Read the Review

round u-bolt kit – grade 8 - 5/8 x 3-1/2 x 11-1/2 8-1038k reviewer
U-Bolts - L&H 8-1038K Rating: 5 Stars

Would Buy Again

Best price around. Shipping was decent. Will shop here again when I need more

Read the Review

round u-bolt kit - grade 5 - 1/2 x 3 x 6-3/4 5-0816k reviewer
U-Bolts - L&H 5-0816K Rating: 5 Stars

Great Product, Great Service

Very high quality product, ease of shopping, and super fast shipping. Thank you!

Read the Review

round u-bolt kit – grade 8 - 5/8 x 3 x 9-5/8 8-1024k reviewer
U-Bolts - L&H 8-1024K Rating: 5 Stars

Chevrolet C 50 Project Truck

courteous and helpfull service team quick shipping and quality products, custom 67 chevrolet c50 truck rolls on your products keep up the great service

Read the Review

3/4 x 2-9/16 x 12-1/2 inch - square u-bolt kit 361-422 reviewer
U-Bolts - Dayton 361-422 Rating: 5 Stars

Spring U Bolts Entry

High quality spring bolts. Fast shipping. Looking forward to winning the !

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round u-bolt kit – grade 5 - 1/2 x 3 x 7-3/4 5-0818k reviewer
U-Bolts - L&H 5-0818K Rating: 5 Stars

Fast Shipping Quality Products

Fast shipping. Used the new U bolts to lift my RV. Work like advertised!

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round u-bolt kit – grade 8 - 5/8 x 3-1/2 x 11-1/2 8-1038k reviewer
U-Bolts - L&H 8-1038K Rating: 5 Stars

Quality Workmanship

outstanding

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round u-bolt kit – grade 5 - 1/2 x 3 x 7-3/4 5-0818k reviewer
U-Bolts - L&H 5-0818K Rating: 5 Stars

Excellent U Bolts

Used these to bolt up a Ford 9" rear axle to my '75 Jeep rock crawler

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round u-bolt kit – grade 5 - 1/2 x 3 x 7-3/4 5-0818k reviewer
U-Bolts - L&H 5-0818K Rating: 5 Stars

Amazing U Bolts

Used these for my jeep cj5 rock crawler that I installed a Ford 9" rear axle. The quality is amazing and the price is the best. Won't use any other companies bolts from here on out.

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round u-bolt kit - grade 5 - 1/2 x 3 x 6-3/4 5-0816k reviewer
U-Bolts - L&H 5-0816K Rating: 5 Stars

Threads Long Enough To Alow Tighting

only place I could find these. Answered my questions quick and with all the specs.

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round u-bolt kit – grade 5 - 9/16 x 3 x 9-3/4 5-0922k reviewer
U-Bolts - L&H 5-0922K Rating: 5 Stars

Perfict Fit

The reason i like this product so much is more to the company having the available part when others didn't. I needed the part fast and got nowhere with other companies and this company gave the details i wanted to know i was buying the right bolt for the suspension i was installing.

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semi-round u-bolt kit – grade 8 - 3/4 x 4 x 7 8-12260k reviewer
U-Bolts - L&H 8-12260K Rating: 3 Stars

Quality Problems

The first batch that I ordered were perfect. They matched up with pre-drilled holes in heavy metal perfectly. The second batch that I ordered had quality control issues as the threaded ends were off by as much as 1/4 inch, requiring much drilling and grinding to use.

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square u-bolt kit – grade 8 - 5/8 x 2-9/16 x 9-3/8 8-1008k reviewer
U-Bolts - L&H 8-1008K Rating: 5 Stars

Ubolts

They have a great selection of ubolts at fair prices

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round u-bolt kit – grade 8 - 3/4 x 3-1/2 x 8-1/2 8-1228k reviewer
U-Bolts - L&H 8-1228K Rating: 5 Stars

Solid Product

Perfect replacement for my 67 Chevy C-10 rear axle U-bolts.

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round u-bolt kit – grade 8 - 5/8 x 3-1/2 x 11-1/2 8-1038k reviewer
U-Bolts - L&H 8-1038K Rating: 5 Stars

What I Expected. Good Quality

I'm using this product for a offroad project. I had a difficult time finding the correct product until i found your website. Product fit perfect.

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