Common screw thread sizes for HO

[Kay.Div.]

Does anyone know what are the common screw thread sizes used in HO.  Since most HO stuff is made in China am I right in assuming they would be Metric.

Thanks.  Kay.Div.

[stokesda]

Well, I think one of the most common sizes used in HO is 2-56, which is an Imperial (non-metric) size - whether the item is made overseas or not. This size is most frequently used to attach trucks to the frames of rolling stock, and in holding coupler boxes together. There are a few other common sizes used in HO, but this is the only one I could correctly recall off the top of my head.

Any particular reason why you are asking? Are you working on a project, or just looking to stockpile?

[richg1998]

Never botherd to measure. If I lose a screw,  I just re-tap with next size up SAE tap. I keep, 00-90, 0-80, 1-72, and 2-56 hardware on hand. I got the taps from Micro Mark. NWSL has a good selection of Metric stuff.

Some LHS shops carry some Metric stuff. My local hobby shop does.

Rich

[Kay.Div.]

Hi Stokesda,    I am installing a decoder in a very old style split frame loco, I can isolate the motor but the trucks have a halfmoon shaped brass contact strip that is in constant contact with the respective halves of the frame there by making each half live. I was planning on installing 2 brass screws into the frame halves to solder the inputs to the decoder on and since I have to buy the taps I might as well get something that I can use again later, such as you say for installing coupler boxes etc.  BTW the frame halves are kept about 1/16th. of an inch apart and held thus by 2 plastic bolts.

Thanks for the info.

Kay.Div.

[richg1998]

Just a guess but you might email NWSL and ask him. He does answer email.

Rich

[zstripe]

Kay.Div.,

Take your pick:

http://www.micromark.com/machine-screws-round-head.html

Another very good source for almost anything you need, taps, screws, nuts and bolts, have used them many times:

http://www.jimorrisco.com/?gclid=CI-Nmovr5rwCFas-MgodsQIAdA

Extremely good souce. RC Airplane and Model Railroad source for fasteners:

http://www.perfectpartscompany.com/

 

 

Frank

[mobilman44]

Ahhh, a subject near (but not so dear) to me..........

I've had three occasions in the last two years to replace lost screws - one from a Spectrum 2-8-0, one from a BLI F unit, and a couple from Stewart F units.   I first went to the manufacturer for replacements and had no success with Spectrum and Stewart not available (from Bowser).  BLI said they would send two.

Anyway, I decided to go to 3rd parties, and I eventually ballparked the size/thread and ordered several selections from a micro fastener company.   They arrived, and I found I could match the threads/diameter and length, but they would not work.  Why?  Because one needed a very thin flat head, another had a small area no thread, and the third had too small a head. 

So I went back to Spectrum (Bachmann) and pitched a mild fit, and they sent me a whole 2-8-0 chassis - rather than two screws.  For the Stewarts, I drilled the holes deeper so as to accept what I had, and then the BLI's finally arrived.

I'm going a long way to say something rather simple....... a lot of the screws on the HO locos are custom, and not readily available from the marketplace.   If you can't get them from the mfg, or improvise yourself, then you may want to pick up a parts loco on Ebay.

Have to say, the "can't find the right replacement screw" is one of the most frustrating situations I've dealt with in the hobby. 

[stokesda]

KayDiv,

Gotcha... Sounds like you are describing the standard design of a Bachmann diesel locomotive. I have a couple of those myself.

For what you're doing, the standard 2-56 screw will work quite well. As it turns out, Kadee sells a 2-56 tap & drill set, which includes the tap and two drill bits (one for a pilot hole for the tap, and the other larger diameter for clearance hole for the screw). Here is a link to the Kadee product. Incidentally, the Kadee website also lists tap & drill sets for 1-72, 0-80, 00-90 sizes as well.

2-56 screws are commonly available from a variety of manufacturers and vendors, including Walthers and your trusty LHS. You might also check out Microfasteners.com if you're buying in bulk.

Good luck!

[cacole]

When it comes to purchasing from "Local Hobby Shops", don't forget places that specialize in aircraft, because they use the same size hardware in many instances and are more likely to have the screws, taps, etc. than a shop that sells trains.

 

[MisterBeasley]

I've always been bothered by the limited availability of stuff like this, and the absurd prices charged at a hardware store for 2-56 hardware.  So, I have been thrilled to do business with a relatively new vendor at our Greenberg train shows.  I think of him as "The Screw Guy."  For a couple of dollars, he sells small bags of screws, nuts and washers.  I've stocked up on various lengths of 2-56 stuff, and also some small self-tapping screws for dealing with plastic.

He also sells CMW cars and trucks, and a good selection of Accurail kits.  I'm so happy to have him at the show for small hardware that I've tried to buy those items from him, too, to keep him coming back.

[cedarwoodron]

Exactly- Hobbytown stores, where RC airplanes and cars seem to be the dominant items, have a parts aisle which includes many small hardware screws. I have had luck finding 2-56 screws and nuts there, as well as metrics which are close enough for an alternative.

Of course, nothing beats buying a bulk quantity of them online and having such a supply readily at hand.

Cedarwoodron

[jrbernier]

  Most HO stuff uses 2-56 screws.  Many LHS's carry them, but the price is rather steep.  Here is a couple alternate choices:

Bolt Depot - A large assortment of screws,and very good prices:

http://www.boltdepot.com/Machine_screws_Slotted_round_head_Brass_2-56.aspx

Accurail - They also sell the black plated screws that are in their kits in bulk packs.  Look in the middle of the following page:

http://www.accurail.com/accurail/parts.htm

Jim

[bigpianoguy]

I'm surprised that no one has mentioned the other standby, the 3-48. This is the one that Atlas uses in their #56 switches and others. After a few emails around I found a Bowser pack on Ebay, before Atlas got back to me with this info:

Part number 9500003 – 3-48 screws, 12 per pack $1.75 per set

 

I hope this helps.

[Greybeard]

A google search for machinery supplies will give you many different sources. Sizes, as already mentioned no need to repeat them. But a general word on taps, I look for Butterfield, Greenfield, R&N, for my taps. 45 years in the machine trade taught me that's not the place to use an oddball brand. One time of trying to dig out a broken tap from the soft alloys used for MRR will explain why.The good ones aren't that expensive, one broken cheap one, where you don't want it is expensive. The machinery suppliers will also carry different kinds, the normal you'll get from the hobby suppliers is a plug tap, but there are times you want a bottom tap that will tap right to the bottom of a hole. Usually no difference in price, just don't try to tap a virgin hole from top to bottom with a bottom tap, it''s made to finish the last couple of turns at the bottom of the hole.