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CE Smith U-Bolt - Stainless Steel - 4" Long x 3-1/8" Wide x 7/16" Diameter - Qty 1

CE Smith U-Bolt - Stainless Steel - 4" Long x 3-1/8" Wide x 7/16" Diameter - Qty 1

Item # CE15503A
Our Price: $14.90
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Multipurpose U-bolt intended for use on trailers to help secure brackets, mounts and cargo. Corrosion-resistant stainless steel construction is ideal for marine applications. Includes mounting hardware. 1-636-306-4830 to order CE Smith boat trailer parts part number CE15503A or order online at Free expert support on all CE Smith products. Great prices and Fastest Shipping for CE Smith U-Bolt - Stainless Steel - 4" Long x 3-1/8" Wide x 7/16" Diameter - Qty 1. Boat Trailer Parts reviews from real customers.
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  • Reviews (29)
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CE Smith Boat Trailer Parts - CE15503A

  • Roller and Bunk Parts
  • U-Bolts
  • 4 Inch Long
  • Stainless Steel
  • 3-1/8 Inch Wide
  • 7/16 Inch Diameter
  • CE Smith

Multipurpose U-bolt intended for use on trailers to help secure brackets, mounts and cargo. Corrosion-resistant stainless steel construction is ideal for marine applications. Includes mounting hardware.


  • Heavy-duty U-bolt helps to secure a bracket to your trailer's frame
  • High quality 316 stainless steel construction is sturdy and resists corrosion
  • Includes 2 washers and 2 nylon lock nuts
  • Made in the USA


  • Quantity: 1 U-bolt
  • Dimensions: 4" long x 3-1/8" wide x 7/16" diameter
  • Threads per inch: 14

15503A Stainless Steel Replacement U-Bolt by CE Smith - 4" Long x 3-1/8" Wide x 7/16" Diameter

Video of CE Smith U-Bolt - Stainless Steel - 4" Long x 3-1/8" Wide x 7/16" Diameter - Qty 1

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Review of CE Smith Boat Trailer Parts - Stainless Steel U Bolt With Mounting Hardware - CE15503A

Hi everybody, Andy here with, and today, we're gonna take a brief look at the CE Smith Stainless Steel U-bolt. Now, this heavy-duty, multipurpose U-bolt is intended for use on trailers to help secure brackets, mounts, and cargo to your trailer's frame, and this is made in the USA of high quality 316 stainless steel construction, making it sturdy and resistant to corrosion, it's gonna be ideal for marine applications, and it includes everything that you see here, the U-bolt and then two washers and two nylon lock nuts. Now, you are going to get one U-bolt, so if you need more than one, make sure that you add additional ones for your order. And let me give you some inside dimensions, I'm gonna pull out my ruler here, and just looking at the inside length here, we're sitting right at four inches long, and then the inside width, we're sitting right at about 3 1/8 inches wide, and then the diameter is gonna be 7/16 of inch. and this threaded section, we're gonna be sitting right at, line that up here for you, the threaded section, we're sitting right at two inches, line that up a little better, two inches, and this is going to be 14 threads per inch. Now, it is important to note that you should apply grease to the threads before assembling the stainless steel hardware to reduce risk of nut seizure.

Well, that's gonna conclude our brief look today, I do hope that it was helpful for you. Again, my name is Andy, thank you for joining me..

Customer Satisfaction Score:

Customer Reviews

CE Smith U-Bolt - Stainless Steel - 4" Long x 3-1/8" Wide x 7/16" Diameter - Qty 1 - CE15503A

Average Customer Rating:  4.6 out of 5 stars   (29 Customer Reviews)

Multipurpose U-bolt intended for use on trailers to help secure brackets, mounts and cargo. Corrosion-resistant stainless steel construction is ideal for marine applications. Includes mounting hardware.


it is a disaster, Yes I was out of town today and I got back and found my order in my mailbox. So tonight I went out to install a tongue jack as I found the dimensions to be almost perfect, it looked like I will have to trim 2 or 3 threads off each bolt end to allow the jack to rotate without interference, Which I have no problem with as there is always some little modification for a part that was not designed specifically for my application, so I installed the U bolts and applied Lubriplate white grease on the threads then installed the washers and nuts supplied and began tightening them, the first three tightened to contact with the frame, my procedure was to snug all four nuts equally, then tighten them finally a little bit at a time, the forth and last nut began to tighten before getting the washer to contact the tongue, As I continued to try to take out the slack the nut seized three threads before initial contact.I tried to back the nut up and it seized further locking onto the bolt. I tried tightening, loosening, nothing worked, I broke a 3/8 Craftsman ratchet trying to get the nut back off. So now it appears that I have to cut the u bolt off. I was a race boat builder and mechanic for several years before I went to a helicopter company and began building and maintaining helicopters for a living for 14 years before working as a Telecom engineer and Network engineer. So I have considerable experience with nuts and bolts, I maintain and build boats and trailers currently.


product as expected
Customer service
and transparency about order delay due to back orders, was lousy.
i ended up cancelling original April 4 order,revised order on 20th to include only those things that you actually had in stock. I could have gotten my stuff on 13th if you had let me know what was NOT available, right away.


Quality at a good price fast shipping very well made


This hardware was made 3 1/8” outside measurement instead of needing to be 3 1/8” inside measurement .
ThAnks hope this was helpful!

I will have our customer service team reach out to you. This u bolt does have an inner measurement of 3 and one eighth inches.
-- Etrailer Expert Jenny N - 01/11/2022


Best Quality!


Product is exactly what I needed. Web site nicely organized. Product arrived in timely manner. Thank you. Will not look anywhere else for future needs.


Fit my boat trailer perfectly


Just what I needed to complete an early 80's EZ Loader trailer restoration. The old bolts/nuts broke off while dismantling, even with penetrating oil. These fit perfectly on the self adjusting roller assemblies... and will last.


Nice, simple, compete. All products nicely packaged, quickly shipped, the order was complete and the phone support was fantastic.

I've been pleased very time I've ordered from

They provide good old fashion, Mom-N-Pop "Local Store" service on the internet.


Quality stainless u bolt.

Still rust free and doing the job as intended.
John S - 06/19/2018


i am a stainless steel freak for all exterior applications. this square u-bolt seems like marine grade stuff at a non marine price. i'm very happy.


etrailer had everything I needed to restore a 1972 Sealion trailer back to it's original condition. Everything shipped fast and was exactly as offered. They sell quality parts at fair prices. I will continue to use them. Dom.


Precisely as advertised


Part came in as advertised. Looks like it's going to be the right fit. Haven't had the time to go put it on the trailer yet. I would use Etrailer again.


Everything fit perfect, quality great.
did have one u-bolt that I could not get the nuts to thread down in place. I actually broke them off while taking them off.


I ordered items by phone. The person who answered was knowledgeable and very helpful in making sure I selected items that would fit my needs. The package arrived just as promised on the day promised. Excellent service and products.


Product arrived in a timely manner and at nearly half the price of the local marine store. Thanks Etrailer.


Very happy with the stainless steel U clamps I purchase.


Received parts on time and exactly as expected. Will use etrailer in the furture.


High quality clamp that fit my trailer frame like a glove.


This product fit exactly the part it re placed


The product was as described. Item was processed and delivered in several days.


It was a perfect fit!



Show More Reviews

See what our Experts say about this CE Smith Boat Trailer Parts

  • Width of the U-Bolt Part # CE15503A
    The distance between the legs of the U-bolt part # CE15503A that you referenced is 3-1/8 inches. Check out the picture I attached. This would fit around a 3 inch square channel.
    view full answer...
    Image 1 for
  • What Grade Stainless Steel are C.E. Smith U-Bolts CE15503A?
    The Stainless Steel CE Smith U-Bolts you mentioned, part # CE15503A are made from high quality 304 stainless steel to prevent corrosion. They are designed for mounting accessories and brackets to trailer frames.
    view full answer...
  • Width of CE Smith U-Bolt # CE15503A
    The 3-1/8 inch dimension on the CE Smith U-Bolt # CE15503A that you referenced is indeed taken from inside to inside on the posts. I have attached an image to assist. It will work great for your 3 x 3 inch trailer frame.
    view full answer...
    Image 1 for
  • Dimensions of Multipurpose U-bolt for Boat Trailers
    I took the measurements of the Multipurpose U-bolt, part # CE15504A, which you can see on the enclosed diagram. You'll note that the length of the U-bolt is 3 inches, which may be too short for your application. The closest sized U-bolt we are going to have is the Multipurpose U-bolt, part # CE15503A, which is 4" Long x 3-1/8" Wide. If these dimensions work for you then part # CE15503A will fit your application.
    view full answer...
    Image 1 for
  • Will the CE Smith U-Bolt # CE15502A Fit Around a 3" Winch Post and Fit Through a 1/4" Plate
    The CE Smith U-Bolt # CE15502A that you referenced is actually only 3" long. If you have a 3" thick winch post and then a 1/4" plate on top of that it will definitely not be long enough to reach. Instead you would want to use a longer U-Bolt like the 4" Long CE Smith # CE15503A. This one measures 3-1/8" Wide and the bolts have a 7/16" diameter just like the one you were looking at.
    view full answer...
  • Stainless Steel Mounting U-bolts for CE Smith CE10161A40 Aluminum Vertical Bunk Brackets
    If you're going to go with stainless U-bolts, go with the 316 stainless if you're using the trailer in a saltwater environment, the extra molybdenum in the 316 will do a better job of resisting corrosion. The CE Smith # CE15503A is the longest stainless u-bolt we offer that has the correct spread to fit the # CE10161A40 bracket you referenced. It's 7/16 in diameter (which would work) and is 4 inches long. The bolt is constructed of 316 stainless steel.
    view full answer...
  • Vertical Bunk Board Brackets for a 216 Sea Pro Boat Trailer
    We do have a few different options for vertical bunk board brackets like the 7-1/2" Tall # CE10603G for you to choose from depending on what you're needing. I've linked our selection for you to filter through. I'm also linking our selection of Stainless Steel U-Bolts that you can filter through. This includes options like the part # CE15503A which measures 4" long x 3-1/8" wide x 7/16" diameter. Since each boat trailer is a little different it's always best to either get parts that have...
    view full answer...
  • Are There Galvanized and Stainless Steel U-Bolt Options Available
    Yes, we do have stainless steel and galvanized square u-bolts available. The CE Smith U-Bolt - Stainless Steel # CE15501A has the same 4" Long x 2-1/8" Wide x 7/16" Diameter measurements as the Trailer Square U-Bolts # 7162184UB you were looking at. I have also listed all of our galvanized and stainless u-bolts below for you. Galvanized: - CE Smith U-Bolt - Galvanized - 4-1/16" Long x 1-9/16" Wide x 1/2" Diameter # CE15282GA - CE Smith U-Bolt - Galvanized - 3-9/16" Long x 1-9/16" Wide...
    view full answer...
  • Aluminum Vertical Bunk Brackets and Stainless Steel U-bolts for Boat Trailer
    The vertical bunk brackets do not have a weight capacity rating. You should be fine with the aluminum, but if you are concerned about the strength then you can stick to the galvanized steel the manufacturer used. - Replacement CE Smith Vertical Bunk Bracket # CE10161A40 (8") - Replacement CE Smith Vertical Bunk Bracket # CE10162A40 (10") - CE Smith U-Bolt - Stainless Steel # CE15503A We do have bunk carpets and bow support options as well, without knowing what size bunk boards and what...
    view full answer...

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Info for this part was:

Employee Jameson C
Expert Research:
Jameson C
Employee David L
Written by:
David L
Employee Wilson B
Updated by:
Wilson B
Employee Hannah L
Updated by:
Hannah L
Employee Manda E
Updated by:
Manda E
Employee Andy C
Installed by:
Andy C

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