When in my late teens I made the change from trying to build a model railroad with American Flyer S gauge to HO, I was impressed with my older brother's use of drills and taps and jewelers screws. Since he was my mentor, he explained that he used the four smallest sizes, 00-90, 0-80, 1-72, and 2-56 for use with HO models. I bought all four sizes of tap drills, taps, and supplies of screws, nuts, and washers in all sizes, and put them into little cardboard pill boxes, neatly labeled.
Big Bro also introduced me to Model Railroader, early on, and while I was still in S, he gifted me with subscriptions to Model Trains, Kalmbach's sister magazine for high-railers and younger (or less experienced) modelers, which shows he supported my "tinplate" ways. After making the change to HO, I modeled diesels because that's what I saw around me, but I later bought an Aristo-Craft brass model of a Ma & Pa #26 Consol cheap, because the cab support had broken loose from the back of the frame during transport from Japan. I was hooked! I graduated high school right about that time and became fascinated by Mel Thornburgh's 6-part series of building an O scale model of a Wabash Mogul from wheels up.
Mel's use of taps and threading dies impressed me, so I made up my mind to someday own an array of threading tools for the larger sizes--which really came in handy when I went into O scale, years later. While working on rebuilding a Ken Kidder O scale "Convertible 2-6-2 Tank Loco," I still struggled with the four smallest sizes of taps and screw sizes, but went back into HO for space considerations. Once my aging eyes suggested I should go back into O to build display models against my coming retirement, I made good on the promise I'd made and added 4-40, 6-32, 8-32, and 10-32--and all the threading dies--to my workshop.
That's when I discovered that commercial screws weren't always of the length I needed, so I made a simple gadget for cutting them down to size. I drilled and tapped two of every size screw in an old HO car weight. I'd determine the length I needed, select the next longer size, thread on a nut (if there was room), screw it into the proper hole until just the excess stuck out, tightened the nut, and sawed off what I didn't need. I always dressed the sawn end to look good, then went happily ahead.
Some years later, I made friends with an old-time "O-Gauger," who'd been building steam engines from the wheels up and "scalized" a couple of today's fairly accurate 3-rail diesels. One of the first things he told me was that he only bought the longest brass screws he could find, not bothering with the smaller lengths. He showed me his little screw plate, saying, "I run the screw in until I have the right length, then clip 'em off with wire-cutters. Backing brass screws out through the steel plate straightens out the threads. No muss, no fuss." (Clearly, this was a "face-palm" moment:Why didn't I think of that?)
Sorry if this got wordy, but I'm pretty sure I should lay in a supply of ginko biloba! My memory seems to have gone to lunch and left me behind--with a blank look on my face...
Deano
Good information Deano!
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Thanks for the info, Dean.
I recently had to purchase some replacement screws for a brass steamer that were a less common size: M1.4mm x 2 & x 3mm. The former was for the gear cover and the latter for the coupler draft gear box (Kadee #234).
I had thought about retapping the holes with the slightly larger 0-80 thread. However, the SS screws were so inexpensive ($4 for 100 off eBay, PLUS free shipping) that I didn't even bother. 2-56 and the occasional 0-80 is what I have on hand for taps and screws.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Great tip.
.
I have done something similar when I need a special screw length. I thread a die onto the screw, clip the end, and them back off the die.
This will not work with extremely short lengths, but it works well.
-Kevin
Living the dream.
Years ago I subscribed to Wood Magazine and I would get a plastic card with holes labeled for screw sizes as a courtesy gift. I still use it in my garage shop frequently. Isn't there a small modeling size equivalent of this available for hobby screws?
Cedarwoodron
Electricans have a tool like that built in to their wire strippers, used to use them all the time.
rrebell Electricans have a tool like that built in to their wire strippers, used to use them all the time.
Yup, I've got one in my toolbox.
For my model railroading projects, like Tom, I usually just buy a box of 100. One reason is that you really should clean up the screw ends after you custom cut a screw. And that's REAL difficult in the smaller sizes. Also, I then have 99 more ready to go.
For actually sizing screws, I use a digital caliper for the diameter. I've also got a thread gauge with about a zillion sample threads. Between these two tools, I can do about any screw. Within reason.
Ed
It's worth acquiring a good quality caliper, either a metal vernier type or a digital one. Also download machinist charts that list clear and tap hole drills for the tiny hardware that we use. My old metal vernier caliper is one of the most valuable tools I own.
Genesee Terminal, freelanced HO in Upstate NY ...hosting Loon Bay Transit Authority, run through Amtrak and CSX Intermodal
CP/D&H, N scale, somewhere on the Canadian Shield
Old ThumperAlso, good to remember: A #0 screw is .060 dia. For every number up from 0, add .013. Ex: The dia of a #4 screw = (.013 X 4) + .060
I did not know that. I put a couple of tables into an excel spreadsheet so I could just pull up by screw and drill bit file, rather than search everytime on the internet.
A caliper is also a must have tool and a cheap harbor freight one is good enough for our purposes.
Henry
COB Potomac & Northern
Shenandoah Valley
There are numerous pre-made screw sizing charts on the internet. The one I printed also has tap drill sizes, and loose and tight clearance drill sizes.
My General No. 1251 Model Railroad Reference Rule has all of that engraved on the backside of it. Decimal equivalents for Fractional drills, Decimal equivalents for number drills, Reference Table tap drill sizes for small screws, 00-90 to 6-32 and a Formula for 75% depth of thread.........I've had it since the late 50's. I believe it cost a $1.50 back then...stainless steel.
Take Care!
Frank
I happened to be in Home Depot today and found what appears to be the exact same vernier caliper that I have been using for 20+ years. It is steel, metric/fractional inch and cost eight bucks. I bought one for my son. Empire brand.