50mm Square Heavy-Duty U-Bolt Kit | Medium & Heavy-Duty Trailers
The Couplemate™ CM603 is a Spring U-bolt kit for 50mm square axles. Designed to secure leaf springs to the axle safely, Couplemate™️ calls these the “heavy-duty” kits because they have thicker U-bolts and fish plates.
Product Specifications
- Internal U-Bolt Width: 50mm
- Internal U-Bolt Leg Length: 180mm
- Thread Type: M16x2 (or 5/8″ UNF)
- Coating: Electro-Plated
Couplemate™️ often supplies Heavy-Duty u-bolt kits with trailer axle rebuilds over 1600kg (up to 4500kg ATM).
This kit is supplied with:
- 4 x U-Bolts
- 8 x Washers
- 8 x Nyloc nuts
- 2 x Fish Plates
- 2 x Axle Pads/Spacers
Installation (User Guide)
Couplemate™️ 50mm Square U-Bolt Kits are accessible for trailer spring maintenance.
- Place a U-shaped curve over the axle beam.
- Align the centre spring bolt and U-bolt legs with the fish plate holes.
- Secure fish plate to leaf spring through supplied washers and nylock nuts. Tighten nuts to 100Nm with a socket.
Important: Check U-bolts and re-tighten nuts after the first trip and every 250 km afterwards.
Safety Precautions
Do not re-use nyloc nuts. Nyloc nuts are often less effective after the first use. This is because the nylon material (the key component of a nyloc nut) has already once conformed to the thread profile.
Do not use a rattle gun to tighten. Rattle guns often tighten U-bolts too fast, too tight, and unevenly, which can cause the nylon to overheat and risk undue wear.
Ensure the axle has welded axle pads. If not, use the axle pads supplied with the spring U-bolt kit.
Are Heavy-Duty U-Bolts worth it?
Within the industry, Trailer U-Bolts lack a standardised testing procedure.
However, Couplemate™ Engineers has developed its rigorous testing method. In this process, we subject u-bolts, nuts, and fish plates to a static load test until destruction occurs.
All of our 16mm Heavy-Duty U-bolt Galvanised Kits undergo a 200-tonne test. During this testing, the u-bolts in the right-hand image ultimately broke at the 23t threshold.
The u-bolts in the right-hand image broke at 23t.
Not convinced? Read why U-Bolts could be the primary cause of highway accidents.
Understanding Caravan and Trailer U-Bolts
- Read why U-bolts could be the primary cause of accidents.
- Loose Axle U-Bolts cause Highway Havoc.
- This article is the catastrophic result of the incorrect tightening of the U-bolt on a truck chassis.
- How to Reduce Dangerous Caravan Vibration Fatigue
Related Towing Products
- 45mm Square Heavy Duty U-Bolt Kit
- 50mm Square x M16 U-Bolt Kit – 180mm Long
- 60mm Round Heavy Duty U-Bolt Kit
- 65mm Round x 16mm U-Bolt Kit – 200mm Long
16mm Individual U-Bolts
Additional information
Weight | 5.1 kg |
---|---|
Dimensions | 20 × 10 × 5 cm |
Coating | Electro-Plated |
U-Bolt Length | 180mm |
U-Bolt Width | 50mm |
Stud Thread | M16x2 |
U-Bolt Application | Spring U-Bolts |
Bolt Diameter | 16mm |
Fastener Type | U-Bolt |
Our Service Lifetime Warranty
Our goods come with guarantees that cannot be excluded under the Australian Consumer Law. You are entitled to a replacement or refund for a major failure and compensation for any other reasonably foreseeable loss or damage. You are also entitled to have the goods repaired or replaced if the goods fail to be of acceptable quality and the failure does not amount to a major failure.
Couplemate™ is a manufacturer and vendor of high-quality towing, trailer, and caravan components. Couplemate™ Core Goods and Custom Work are guaranteed to be free of defects for the service lifetime of the product when used as intended.
Warranties are non-transferrable and Couplemate™ requires satisfactory proof of purchase prior to issuing a remedy. The full Couplemate™ Warranty Policy can be found in the Terms & Conditions: Section 8 – Consumer Guarantees & Warranty.
Warranties are in addition to your rights under the Australian Consumer Law. If something is wrong with your order, please contact our team.
60-Day Returns
After 60 years of experience, we know that life has its unpredictable moments.
All Couplemate™ orders (online, over the phone, or in-store) have a 60 day period for change-of-mind returns and exchanges. There are some items that can’t be returned and some returns may incur a 15% restocking fee.
You can view our full policy for change-of-mind returns here.
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