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  1. Trailer Door Hinges
  2. Redline
  3. Hinge Pin
  4. Build Your Own Hinge
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  6. 4-3/4 Inch Long
1/2" Diameter Greasable Hinge Pin, 4-3/4" Long with 3/4" Base

1/2" Diameter Greasable Hinge Pin, 4-3/4" Long with 3/4" Base

Item # HP12412G
Our Price: $13.41
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Trailer Door Hinges
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Shipping Weight: 0.56 lbs
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Hinge pins are welded to either the outer frame or the gate/door and then inserted into the welded hinge pin nipples to create custom, heavy-duty hinges. Greasable pins feature a grease zerk for lubrication. Great Prices for the best trailer door hinges from Redline. 1/2" Diameter Greasable Hinge Pin, 4-3/4" Long with 3/4" Base part number HP12412G can be ordered online at or call 1-800-940-8924 for expert service.
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  • Reviews (139)
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  • Videos (1)
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  • Why etrailer?

Redline Trailer Door Hinges - HP12412G

  • Hinge Pin
  • Build Your Own Hinge
  • Greasable Pin
  • 4-3/4 Inch Long
  • 1/2 Inch Diameter
  • Weld On
  • Redline

Hinge pins are welded to either the outer frame or the gate/door and then inserted into the welded hinge pin nipples to create custom, heavy-duty hinges. Greasable pins feature a grease zerk for lubrication.


  • Build your own hinge
  • Great for trailers and agricultural applications


  • Outer diameter 1/2"
  • Base diameter 3/4"
  • 4-3/4" long

HP12412G, Hinge Pin Nipple Assembly Greasable 1/2" Pin, 4 3/4" Long

Video of 1/2" Diameter Greasable Hinge Pin, 4-3/4" Long with 3/4" Base

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

Video Transcript for Redline Enclosed Trailer Parts - Doors - HP12412G Review

Customer Satisfaction Score:

Customer Reviews

1/2" Diameter Greasable Hinge Pin, 4-3/4" Long with 3/4" Base - HP12412G

Average Customer Rating:  4.9 out of 5 stars   (139 Customer Reviews)

Hinge pins are welded to either the outer frame or the gate/door and then inserted into the welded hinge pin nipples to create custom, heavy-duty hinges. Greasable pins feature a grease zerk for lubrication.


This low profile but strong hinge really sets off the crisp oak tailgate for the home rebuilt utility trailer. Coupled with some 2 in angle screwed into 5/4 rough oak, allows right offset to lower hinge body below deck line for welding onto rear box tube. Gate pulls off and leaves nothing protruding for sliding in cargo.

Also, then it leaves a great positive secure engagement point for motorcycle ramp attachment. Sweet product!


George: Sorry it has taken this long to get a review back to you but just finished my project. Converted my 5 x 8 tilt trailer to one with a rear Gate by using your hinges. Worked perfectly.


Great shipping and packaging of product.


Did not work for my application, went a different way, but appeared of good quality. Unable to speak to its longevity as they are in my parts bin.


Installed a yr ago. Perfect product.
thing for me though....
I had to buy different fenders because I bought better tires and rims for this new axle which turned out to be slightly wider.
So the original fender would have cut into the tires.
I got everything from etrailer. Axle with brakes fully assembled, controller, fenders, wire harness, connections tires, time and more...and couldn't be happier with cust service, pricing and availability.


Hey there! Other than accidentally welding in the wrong spot one time, these are absolutely the greatest hinges I've ever found, and at a great price. Currently assembling my 5th motorcycle trailer in the last two years, and would recommend these 3 at a time, for strength of ramps for large american bikes, that occasionally weigh as much as 1100 lbs... and have yet to break a hinge, though I did break a weld once (obviously my fault for a junky weld that time).... Great product, great service, quick responses. Thanks for being a great company. Will be ordering again!!!!


I've been using etrailer for the past 10 years and have never been disappointed. I'm using this product to make a VW bus side car for my scooter and it is exactly what I'm looking for. In the past I've used many different towing hitches and every one has been top notch and the cost, shipping and product quality has been great. I'd like to give a shout out to the customer service department but to be honest, I've never had to use them. Cheers!


The quality is good and they work just as good.


Just what I wanted. When ever I’m looking for a trailer part has what I need. Keep up the good work and Thank You.

Mary A - 04/24/2019


I welded each half to a piece of angle iron and bolted one half to the trailer frame and the other half to the ramp. Worked great and the because they are greaseable I think they will work for many years.


Worked like a charm! Welded this in to replace a seized-up hinge pin. Perfect fit AND a grease fitting to ensure long service and smooth operation. Etrailer shipping is super fast. Very pleased.


Quick shipping item exactly what we ordered at a good price. We will use etrailer again in the future and recommend them for your trailer parts needs. Oh and they kept us informed by email of where the part was in the mailing process to billing to delivery. Thanks again etrailer.


I used item to support a solar panel rack on my boat that is a few hundred pounds. Very happy have had no issues A+


Product is just as pictured, nice quality, and should work well. I bought three of these to use on a trailer ramp/tailgate. It was cheaper for me to buy these, than spend the time turning them up on the lathe, plus the cost of materials.


A year ago I needed to do a basic repair to my trailer. I found to be prompt and the right price (same part was more expensive at our local feed-store.) Polite and professional they are an outfit I will use again.



Great trailer door replacement hindge I ordered 3 thinking they would not hold the weight of my ramp door on my sled trailer after welding two in place i think the third was overkill. Easy to use worked like silk great thing with the zerk fitting for grease every season.


Received product 4 days after placing order. Using product to replace a hinge on a trailer gate that was damaged.

no issues with the hinge after having it a year
steve - 03/18/2015


e trailer had exactly what i need and they made it easy to order and followed up on the sale and as a ex Customer Service Manager I had a positive experience with every step of the process. e trailer is saved in my Favorites and will be the first click next time.


Quality product. It's machined very well and has nice fitment on the grease fittings. Shipping was quick and with tracking. This is my third order with etrailer, and all have been great.


I think these will do what I want! My trailer came with a non removable drop gate. At times I would like to take drop gate off so I can get a wheel barrel close to shovel mulch into it. I believe I should be able to weld these on the cut original hinges off allowing that to happen!


Just what I had been looking for now gate want squeak since it grease able and fast shipping

Still holding strong
Shane - 11/16/2018


I was astounded that my hinges showed up in the same week I ordered them, and I was very pleased with the quality of the parts, especially have the zerk fitting option!! The choices were abundant but these are similar to what seized up on my own trailer and ripped the skin of the trailer, so these will be a quick fix for my welder. Thanks for the prompt service! Randi


We had a little mishap in the order and it was taken care of ASAP. Ended up sending ones that was damaged in the order. Very happy with this company. Now my horse trailer can get fixed. I will be ordering from these guys again. Thanks etrailer for all the hinges


This works good for my 5×8 utility trailer but really should have gone the next size up.but it does work well


etrailer is an excellent vendor, repsonsive to the order and delivery of the products. Everything I have received has been exactly what I expected from the web site. Good Company, try it for whatever you need.

Show More Reviews

See what our Experts say about this Redline Trailer Door Hinges

  • Weight Capacity For Redline 1/2 Inch Greasable Hinge Pin
    I called my contact at Redline and they told me that the weight capacity for the 1/2 inch Diameter Greasable Hinge Pin, part # HP12412G is 420 lbs. They did stress the weight capacity can vary due to the installation. They recommend using a certified welder to attach the hinge and to make sure there are enough hinges installed to be able to handle the weight of the gate or door it is being used on. I have attached a link to a product review for this hinge you can check out.
    view full answer...
  • Will the Redline Greasable Hinge Pins HP12412G Fit on a 2006 Gearbox 335FS Toy Hauler
    The Redline 1/2 Inch Greasable Hinge Pin, # HP12412G, is a great option to replace the missing hinge pins on your 2006 Gearbox 335FS toy hauler. These hinges are a universal fit item and include a grease zerk fitting for easy lubrication. If only some of your pins are broken, then you may want to measure the sizes of your remaining hinge pins so you can purchase the correct size replacements. We carry 1/2 inch and 3/4 inch hinge pins. I have attached a link to all of the hinge pins we...
    view full answer...
  • Using 1/2" Diameter Greasable Hinge Pins to Make a Detachable Ramp
    On the 1/2" Diameter Greasable Hinge Pin, 4-3/4" Long with 3/4" Base Item # HP12412G you would need 2 sets and they would have to be facing the same way in order to make the ramp detachable. But yes, you could do it.
    view full answer...
  • Diameter of the 1/2" Diameter Greasable Hinge Pin
    The part # HP12412G is 4-3/4 inches long overall not including the grease fitting. The outside diameter is 3/4 inches. That is the portion of the hinge that gets welded to a trailer. The inner portion that inserts into the other part of the hinge is 1/2 inch.
    view full answer...
    Image 1 for
  • Are Trailer Ramp Hinges Friction Fit To Each Other
    To separate the sections of the 1/2" Diameter Greasable Hinge Pin # HP12412G that you referenced you would not have to pound on them with a sledge hammer. That would imply to tight of a fit for the hinge to swivel and function. If you check out the review video I attached you will see how easily the two pieces slide into each other. Normally to remove hinges you have to separate one side of the hinge from either the door or the opening so that the two pieces can slide out from each other...
    view full answer...
  • Is Trailer Ramp Hinge Part # HP12412G Weldable
    Actually the 1/2" Diameter Greasable Hinge Pin # HP12412G is not zinc coated or galvanized. It was designed to be welded so there wouldn't be an issue if you did so. It's not the prettiest weld, but I did attach a picture of this welded to a trailer for you to check out as well.
    view full answer...
    Image 1 for Image 2 for
  • Recommendations for Converting a Barn Trailer Door to a Ramp Door
    To convert your barn door on your Wells Cargo enclosed trailer to a ramp door I would recommend you use the Universal Cam-Door Lock for Enclosed Trailers # 383200 that you referenced as well as a 3/4 diameter pipe that you will need to get from a hardware store. For a hinge mechanism, if the current hinges you have are not adequate, I would recommend you get three 1/2 inch Diameter Greasable Hinge Pins # HP12412G to use as door hinges. You might also be interested in purchasing a Ramp...
    view full answer...
  • Ramp Hinge Recommendation for a Replacement Hinge for an Enclosed Trailer
    A piano hinge like the part # SH300 could work very well for a replacement hinge for your enclosed trailer. This hinge is 6 feet long and 3 inches wide. A co-worker here used 3 of the Greasable Hinge Pin, # HP12412G, for a similar application and that is what he recommends using over the piano hinge.
    view full answer...
  • Can Stainless Steel Hinge, # SH300 be Used as the Hinge on an Enclosed Trailer Ramp and Door
    While it is possible that the Stainless Steel Hinge, # SH300, will work for your application, I believe that there are better and more reliable options. A co-worker here used 3 of the Greasable Hinge Pin, # HP12412G, for a similar application and that is what he recommends using over the piano hinge.
    view full answer...
  • Are There Other Parts Needed When Installing a Greasable Hinge Pin # HP12412G
    You will not have to purchase 1/2 inch Diameter Hinge Pin Nipple # HPN214 to install a 1/2 inch Diameter Greasable Hinge Pin # HP12412G. The # HP12412G already comes with a base with a grease fitting, so the # HPN214 would not be necessary. Check out the pic I attached that shows the grease zerk fitting on the # HP12412G
    view full answer...
    Image 1 for
  • 6 inch Long Trailer Hinge that is 3/4 inches in Diameter
    For a 6 inch long hinge setup that has a 3/4 inch diameter you would want the part # HP34G and # HPN3342. These two pieces together will give you a hinge in the dimensions you requested.
    view full answer...
  • Recommended Gate/Ramp Assist and Hinge for Trailer Build
    The 2K Torque Ramp Spring # RS16933RH is an industrial strength spring. It is designed for up to 90 degrees of deflection, but most people by hand can cause no deflection at all. It is designed to be used with the LH # RS16933LH, and is for heavy ramps or doors like in the attached photo. I would assume it is too strong for your application based on your wording. You may want to consider a different style spring like the Enclosed Trailer Ramp Spring - Dual Spring, 81" Wide # ERS120D81...
    view full answer...
    Image 1 for Image 2 for

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