Semi-Round U-Bolts 1" + diameter - Grade 8

To Purchase Grade 8 Semi-Round U-Bolts

The chart below provides quick reference to the 1" diameter and larger Semi-Round u-bolts we have in stock. Each kit contains:

Round U-Bolt Kit
  • 2 u-bolts
  • 4 washers
  • 4 nuts

Once you find the u-bolt that meets your requirements, click on the 'buy' link to add the u-bolt to your cart, and review pricing. On the cart page, specify the number of KITS you would like to purchase, and checkout.

How to Measure a Semi-Round U-Bolt

How to Measure U-bolts

  • Determine the type of bend (Round, Semi-Round, or Square)
  • Measure the diameter of the Rod ("A")
  • Measure the distance between the Legs ("B")
  • Measure the length of the leg ("C")

In the chart below, Part #8-16100K is 1" diameter x 4-1/8" wide x 13-3/4" long.

Grade 8 Common Semi-Round U-Bolts - 1" Diameter & Larger
      Rod   Click for
Part # Dimension Bend Length Application Price
8-16100K 1 x 4-1/8 x 13-3/4 Semi-Round 32 Peterbilt Buy
8-16110K 1 x 4-1/8 x 14-3/4 Semi-Round 34 Peterbilt Buy
 
8-18100K 1-1/8 x 4-1/16 x 12-1/2 Semi-Round 30 Mack Buy
8-18110K 1-1/8 x 4-1/16 x 13-1/2 Semi-Round 32 Mack Buy
 
8-20100K 1-1/4 x 4-1/16 x 13-1/2 Semi-Round 32 Mack Buy
8-20110K 1-1/4 x 4-1/16 x 14-1/2 Semi-Round 34 Mack Buy
8-20120K 1-1/4 x 4-1/16 x 15-1/2 Semi-Round 36 Mack Buy
8-20130K 1-1/4 x 4-1/16 x 16-1/2 Semi-Round 38 Mack Buy
8-20140K 1-1/4 x 4-1/16 x 17-1/2 Semi-Round 40 Mack Buy
8-20150K 1-1/4 x 4-1/16 x 18-1/2 Semi-Round 42 Mack Buy
8-20160K 1-1/4 x 4-1/16 x 19-1/2 Semi-Round 44 Mack Buy
 
8-20180K 1-1/4 x 5-1/16 x 16-1/4 Semi-Round 38 Mack Buy
8-20190K 1-1/4 x 5-1/16 x 17-1/4 Semi-Round 40 Mack Buy

Need Custom Bent U-bolts?

Call 1-800-358-4751 for expert advice on U-Bolts. Or send us an email. We're open (Eastern Time Zone):
  • M-F: 7am - Midnight
  • Sat: 8am - 1pm
Secure online ordering is available 24 hours a day, 7 days a week.

Threaded Rod & U-bolt Links

About U-Bolts

U-Bolts on many suspensions provide the force necessary to create what is called the center clamp. This provides the permanent tie between not only the spring leaves, but between the spring and spring seat as well. The clamp performs the following functions:
  • Attach the spring firmly to the axle seat
  • Prevent leaf breakage through the center bolt section
  • Prevent center bolt breakage due to shear

U-Bolt Q&A

Q.  If I'm replacing a spring, can I re-use the old u-bolts?

A.  No, you should never re-use u-bolts. A properly installed U-Bolt stretches a little bit under torque. The results of this small amount of stretching and its effects on the U-Bolt threads and deep nut, lower a used U-Bolt's ability to sustain the required clamping torque.

Q.  Is torque important when I tighten u-bolts?

A.  You bet it is. The following are a list of common problems resulting from improperly torqued u-bolts:
  • looseness in seat area
  • excessive wear on chassis components
  • possible spring breakage
  • possible axle slippage and misalignment