# What size truck screws for freight cars?



## Mikepro (Nov 27, 2018)

I recently purchased 2-56x1/4 screws to attach the trucks to the freight cars however this size was too wide and will not thread in, does anyone know the correct size off hand?
Thanks


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## wvgca (Jan 21, 2013)

2-56 is -normally- the correct size ... however you may need to tap the receiver or base of the truck ..


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## Mikepro (Nov 27, 2018)

Ok thanks, I was able to get the screws in with some force, my next question is do I have the correct trucks on this freight car? And if so what couplers will I need to attach them to the next freight car?


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## traction fan (Oct 5, 2014)

*Smaller screws? or bigger holes?*



Mikepro said:


> I recently purchased 2-56x1/4 screws to attach the trucks to the freight cars however this size was too wide and will not thread in, does anyone know the correct size off hand?
> Thanks


Mikepro;

There are smaller screws made, much smaller, but they are sometimes a little more difficult to find. Some hobby manufacturers make screws down to size 00-90 (VERY small) "Hob bits" is one brand) They are sold in some well-equipped hobby stores, especially those few specializing in model trains. (My local one, Reeds Model Trains in La Mesa Calif. sells them.) They are usually sold only in packs of five screws and are very expensive compared to larger screws at Home Depot.

I think wvgca's idea is more practical. If the 2-56 screws wont fit through the truck bolsters, but are close, drill out the hole a little bigger. And, as he suggests, drill and/or tap the car body as necessary.

Apparently your second post, (with the photo), and my now-obsolete answer crossed in cyberspace. When I went to post my answer to you first question, your second post had just appeared.

As for your question, "Are these the right trucks for a freight car?" that depends on how accurate you want to be, and what characteristics you want in your model trucks. Also, since you sent only a bottom view, and no side view, it's not easy to tell which kind of truck you have.

The types of trucks used on prototype (a.k.a. real) freight cars varied with the era in which the car was used, and how heavy a load it was designed to carry. In model terms, (unless you are trying to duplicate, rather exactly, a particular real car) the prototype variations (there were dozens) don't matter all that much. 

For my model freight cars I prefer metal wheels. (actually I'd love to have all-metal trucks, but they don't make any in N-scale. )

In HO-scale, Kadee does make metal trucks, with metal wheels. They have an excellent reputation for free rolling and general quality. Metal wheels can also be purchased to fit into plastic trucks from different manufacturers. Metal wheels roll better, stay a little cleaner, and add weight where it is most needed for better tracking, at the bottom of the car. (This is why I'd like to have all-metal trucks. Are you listening Micro-Trains?  )

As for couplers, you can't beat Kadee. I'll leave it to the HO-scale modelers to recommend their favorite type/number Kadee coupler. 

Good luck;

Traction Fan:smilie_daumenpos:


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## wvgca (Jan 21, 2013)

Mikepro said:


> Ok thanks, I was able to get the screws in with some force, my next question is do I have the correct trucks on this freight car? And if so what couplers will I need to attach them to the next freight car?



well, it depends more than anything on era .. but if you're not fussy probably most trucks will fit ...
and couplers ,, well i'm partial to Kadee number 5's ...


the tap for 2-56 screws would probably be a good idea to get, along with a NMRA metal guide plate, and a Kadee coupler height gauge [plastic one preferably]


have fun


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## ebtnut (Mar 9, 2017)

You didn't identify the car itself. It's hard to tell from the one pic, but it might be European or Chinese, in which case the truck screws would be metric rather than US thread. Two millimeter screws are common for this purpose. Kadee makes a variety of couplers to fit different types of cars. Check their web site for more data.


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## Mikepro (Nov 27, 2018)

Sorry, here is the side profile


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## flyboy2610 (Jan 20, 2010)

From what I can see those are solid bearing trucks, sometimes incorrectly referred to as friction bearing, which would be appropriate for a car built in 1950. My 'go-to' coupler is a Kadee #148. I'll try that first, then make adjustments or change to a different Kadee coupler if needed depending on the coupler height as measured with the Kadee gauge.


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## DonR (Oct 18, 2012)

Amen on the 148 Kadee couplers. They use the simple
'whisker' centering spring which is so much easier
to assemble than the equally good 5's but are difficult
to assemble. The 148's are used in the vast majority
of installations.

Kadee has a good variety of special couplers with the
knuckle over set or under set. These are used for
vertical alignment of body mount couplers when
the car body is too high or too low. Others are
available with various length shanks.

By all means obtain the Kadee plastic coupler alignment
tool. It assures that your couplers are vertically
aligned which eliminates most unintended uncoupling.

Roller bearing trucks are mandatory on US railroads today.
However, if your layout has a 'time present' before the
60s you would find the old fashioned trucks that used
a wad of cloth soaked in oil in the journals. These often resulted in smoke and fire, which were referred to as a 'hot box'.

Don


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## Eilif (Nov 6, 2017)

One more vote in favor of #148 couplers. Nothing wrong with #5's but I've found #148's to be easier installation.
I buy them in bulk, but when bought in 2-pair envelopes they come with the improved snap-top coupler box (#5 comes with the old style 3-screw) that is less bulky and easier to use


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## cv_acr (Oct 28, 2011)

#5s and #148s are equivalent except the 148 has the wire "whisker" spring instead of the separate formed bronze centered spring of the original #5.

I like to use the smaller head #58/158 couplers for better "scale" appearance. The smaller size will be slightly more sensitive to differences in vertical alignment, but if you take the proper care to get things at the right height and don't have kinky, bumpy track (the most important thing you can do anyway to ensure any type of reliable operation) they work just as well and are 100% compatible with #5/148 couplers as well.


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## CTValleyRR (Jul 26, 2014)

I would say that the exact Kadee coupler doesn't matter much, or you could use an IDENTICAL clone, like a Walthers PROTOMax. Do not, however, buy the cheap knockoffs, which may look the same, but being made of plastic, are not nearly as durable.

For the trucks, find a photo of a prototype car and buy a pair that is close. If you care about a exact match, Model Railroad Hobbyist magazine has done a few articles on trucks in the past few years that will help you dial it in. Go to www.model-railroad-hobbyist.com to subscribe (it's free). As the others have said, metal wheelsets are generally preferable to plastic.


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## Mikepro (Nov 27, 2018)

Thanks for all of the great info!


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## Mikepro (Nov 27, 2018)

I purchased 4 sets of kadee 148 couplers, I received them on Thursday and unfortunately they don’t look like they are correct for the trucks on the train in the picture, I will need a different coupler.


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## CTValleyRR (Jul 26, 2014)

Mikepro said:


> I purchased 4 sets of kadee 148 couplers, I received them on Thursday and unfortunately they don’t look like they are correct for the trucks on the train in the picture, I will need a different coupler.


No, you just need to make a few modifications. A quality knuckle couple like the ones you bought are not going to be a drop-in replacement for those trucks. But trust me, you don't want to use any coupler that would be a drop-in replacement on those trucks. I guess they guys assumed you knew that, or would figure it out.

And BTW, do you have a coupler height gauge, or at least a NMRA standards gauge, so that you know they are at the proper height once you're done? If not, get one before you tackle this project. Poorly matched coupler heights is a recipe for trouble.e

Your best course would be to cut the old tab off the truck, and body-mount the Kadees, shimming them down to the proper height. Body-mounted couplers perform much better than a truck mounted one. If you don't want to do that, you can either nip off that little pin in the center and the side lips and use the coupler box from Kadee. Or use the existing box, and use a small piece of styrene tube to enlarge the pin to the proper size.


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## Old_Hobo (Feb 20, 2014)

I think you're confused, CVT....and the OP apparently is too.....the trucks in his photos are not talgo type, the coupler box is clearly on the car, so those #148's should fit perfectly......


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## CTValleyRR (Jul 26, 2014)

Old_Hobo said:


> I think you're confused, CVT....and the OP apparently is too.....the trucks in his photos are not talgo type, the coupler box is clearly on the car, so those #148's should fit perfectly......


Nah, you're right. That's what comes from doing this on a tablet. I didn't blow the picture up enough to see all the detail. The OP didn't help by referring to the couplers not being right for the trucks... I assumed (yeah, I know) that the coupler pockets were on the truck.


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## Mikepro (Nov 27, 2018)

They will have to be modified, the new couplers are too large to fit in the existing spot, and I appreciate everyone’s help, I have no experience working on model trains, and am just now figuring this stuff out.


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## flyboy2610 (Jan 20, 2010)

Can you post a good closeup of the coupler boxes?


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## CTValleyRR (Jul 26, 2014)

Mikepro said:


> They will have to be modified, the new couplers are too large to fit in the existing spot, and I appreciate everyone’s help, I have no experience working on model trains, and am just now figuring this stuff out.


Well, then you're probably back to my original suggestion: file off the stock box and use the one that came with the Kadee. Some pix of how and where you think it doesn't fit would be helpful, though.


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## Mikepro (Nov 27, 2018)

Here is a picture to show the size comparison


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## Mikepro (Nov 27, 2018)

Another pic


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## Eilif (Nov 6, 2017)

Kadee #148 should fit in there. Even if they hang out the end a bit. It's ok for the wires to stick out.


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## flyboy2610 (Jan 20, 2010)

I'm guessing the problem is that the hole in the Kadee shank is too big for the pin and it moves around too much?


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## Murv2 (Nov 5, 2017)

Awesome car! I love the older stuff that's made out of wood and metal instead of plastic. Perhaps the easiest option would be to take the plastic Kadee box you have there, cut the sides off so it's flat but for the center pin and use it for a lid for the pocket, just gluing it in place (Kadee #5 sets have flat lids with center pins already). Fast but not recommended because you can't fix it easily once the glue sets. Another option (probably the one I'd take) is to cut off the center pin in the pocket (I'd use a pair of diagonal cutters to get the bulk then file it flat), drill and tap the position for a 2-56 screw. Kadee provides plastic screws in many of their sets and your local hobby shop will probably have the right size tap. I strongly recommend getting the coupler height gauge, you find yourself using it over and over. Kadee also provides shims for height adjustment.


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## Eilif (Nov 6, 2017)

flyboy2610 said:


> I'm guessing the problem is that the hole in the Kadee shank is too big for the pin and it moves around too much?


I don't think that's an issue with 148's. The two wires extending from the box constantly pull the coupler forward and center. I've got plenty of 148's in applications where the pin is a tiny little rivet and they center nicely. 

As well as the easy installation one of the best things about 148's is the rather wide range of spaces they work within. I've got them in big coupler boxes with tiny pins and conversely coupler boxes where both the pin is too big and the box is too small for a #5. (I'm looking at you Bachman...)


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## CTValleyRR (Jul 26, 2014)

Looks like it's exactly the right size to me. The pocket that came with the Kadee is exactly the same size as the original.

Getting a pocket to hold the coupler in place is a matter of combining parts of the boxes, or as Murv said above (and I said in my original post) just remove the old parts with nippers, a file, etc.

The only issue would be whether the coupler actually fits inside that box, and since the old and the new are the same dimensions I am sure it will. You need to make absolutely certain that the height is correct, though. A coupler height gauge is the best tool for that, but an NRMA standards gauge will work.


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