Understanding Trailer Leaf Spring Capacity When Building Trailer

Updated 05/30/2019 | Published 05/28/2019

Products Featured in This Question

6-Leaf Double-Eye Spring for 7,000-lb Trailer Axles - 24-7/8" Long

(2045)

$73.50

4-Leaf Double-Eye Spring for 3,500-lb Trailer Axles - 25-1/4" Long

(2043)

$48.37

Detail K2 Mighty Multi A-Frame Utility Trailer - 7-1/2' Long - 1,640 lbs

(9)

$2022.55

Question:

Hello, I am just starting out to build a few Utility Trailers for myself and family and something I wasnt sure about was the weight capacity of Spring Leafs. I understand that axles and springs have different weight ratings and lengths, but some I am unsure of is about how some springs are advertised. If I have a 7000 lb 85inch axle does that mean that I would need to get 2 springs that have a rating of 3500 lb? Or would that mean I have to get 2 springs rated at 7000 lb? The same on if I have a 3500 lb 85inch 5 on 4.5 axle. Would I need 2 springs rated at 1750 lb or 2 at 3500 lb? It seems like a basic easy to understand thing that I shouldnt need to ask about, but when I look online at local stores the springs are marketed and sold individually so it makes me unsure. Also I was wondering if you could reply with a list of parts needed to make a full trailer. Currently my list is: Axle, Tires, Spring Leafs, Hanger Kit U-bolts, Hangers, Bolts, Nuts, Lights, the red and white stickers that go on the side?, Hitch mount/coupler, Front Jack Mechanical or Weld-on, Wheel wells Thank you for your time

asked by: Kyle

Expert Reply:

The combined weight rating of the two leaf spring sets (one on each side of the axle) needs to match the capacity of the axle. This means for a 7,000 pound axle each spring set will have an individual capacity of 3,500 pounds, such as with the 6-Leaf Double-Eye Spring # e64SR. For a 3,500 pound axle each leaf spring would have a 1,750 pound weight capacity like on # e54SR.

I have attached a link that will take you directly to our selection of trailer leaf springs. On the left side of the page you can click on your axle capacity to bring up the selection of appropriately rated leaf springs.

Do you have a particular weight rating in mind for your trailers? Are you looking for a list of specific part numbers or just a general component list of what would be needed to build one?

In addition to the list you provided you are going to need steel and wood for the framing and floor, hub assemblies, wheels, fenders (not necessarily required), wiring for the lights and also for electric brakes if you are adding these, and brakes assemblies (if needed).

We do also have utility trailers available like the Detail K2 # K2MMT5X7 that come with all the needed parts. This particular trailer features a payload capacity of 1,640 pounds with bed dimensions of 88 inches long and 52 inches wide. I have attached a video demonstration that you can check out as well.