TheRailwire

General Discussion => N and Z Scales => Topic started by: sd75i on August 24, 2019, 09:23:35 PM

Title: Small Screw
Post by: sd75i on August 24, 2019, 09:23:35 PM
 I am looking for help finding some of these or maybe the right name for them?  Slotted shoulder screw??
Title: Re: Small Screw
Post by: u18b on August 24, 2019, 09:33:43 PM
Looks like the drawbar or coupler screw to some brass locomotives or passenger cars.

Or is it a truck or tender screw?
Title: Re: Small Screw
Post by: garethashenden on August 24, 2019, 09:41:40 PM
Slotted shoulder screw is a good description. Here are a bunch: https://www.mcmaster.com/shoulder-screws
Title: Re: Small Screw
Post by: sd75i on August 24, 2019, 10:35:08 PM
  It holds the track cleaning pad on a roco track cleaning car.
Title: Re: Small Screw
Post by: kornellred on August 24, 2019, 10:44:25 PM
This type of screw fastens Samhongsa trucks to brass diesel chassis when used with a washer and spring.
Title: Re: Small Screw
Post by: narrowminded on August 24, 2019, 10:46:07 PM
Do you have the actual screw dimensions?  One possibility to make up your own might be a piece of tubing on a standard screw.
Title: Re: Small Screw
Post by: bbussey on August 25, 2019, 09:18:41 AM
If it’s from a Roco item, it’s probably a metric machine screw. Measuring the diameter and length in millimeters will get you the basic fastener designation — M{diameter}x{length} — and then tubing can be used for the shoulder as suggested above.
Title: Re: Small Screw
Post by: UP4-8-8-4 on August 25, 2019, 10:49:22 AM
https://www.pic-designcatalog.com/shoulder-screws/slotted-head-shoulder-screws/



Title: Re: Small Screw
Post by: sd75i on August 25, 2019, 01:08:23 PM
  This is best I could do.  I do like the idea of tubing over it!  I used a micrometer for measurements. 
Title: Re: Small Screw
Post by: mmagliaro on August 25, 2019, 04:35:11 PM
If I read your measured drawing correctly, the diameter across the threads is 2.86mm.  If that's right, then it is most likely an M3 screw.

These are not hard to find.  If you don't have an assortment of metric screws and nuts at home, you can take one to your local hardware store, like an Ace - they have metric screws that small and they have the nuts to match.  You can play with the sizes in the box at the store until you confirm what nut smoothly threads on to your screw.  If you don't have any of the screws, just the car, then take the car to the store and test with some M3 or M2.5 screws until you make sure of the thread.  There are different thread pitches for these, so be aware.  Hardware stores usually list them as "fine", "standard" and "coarse" or something like that.  You could have an M3 "fine" or an M3 "standard", for example.  You will have to just test your screw on nuts in the store. to figure out what you have.


Title: Re: Small Screw
Post by: narrowminded on August 25, 2019, 07:14:27 PM
If I read your measured drawing correctly, the diameter across the threads is 2.86mm.  If that's right, then it is most likely an M3 screw.

I'm reading the 2.86mm dimension as the barrel diameter with the thread being 1.89mm or at the lower end of spec for a 2mm thread.  Thread pitch still up for grabs.  If you can get your hands on a thread gauge you could get the answer for sure.  Even a lot of mechanics will have one of those. 
Title: Re: Small Screw
Post by: mmagliaro on August 26, 2019, 06:37:33 PM
Oh yes... I see now.... That 2.86 is supposed to be around the shank.  I thought it was the diameter across the threads and the 1.89 was the inner diameter of the threaded part.  But that would be kind of hard to measure, eh?   ;)  Okay... so probably M2. 

A quick stock check online shows that Home Depot carries those.  Ace only lists M4 and larger.
So it will depend on what hardware stores are handy to you if you don't want to go online.
Title: Re: Small Screw
Post by: sd75i on August 26, 2019, 11:58:42 PM
  I will check HD when I get back in town!
Title: Re: Small Screw
Post by: bbussey on August 27, 2019, 10:22:15 AM
Looks like M2x12.  Amazon carries a large variety of micro metric screws at a good price with fast delivery.  Search for the manufacturer Uxcell.
Title: Re: Small Screw
Post by: MK on August 27, 2019, 04:57:25 PM
IF there is a LHS near you that carrys R/C airplanes and cars, they typically use metric screws M3 and under.
Title: Re: Small Screw
Post by: sd75i on August 28, 2019, 01:59:04 PM
 I kinda live in the forest but I have to go to work and pass by a few places.  I'll check both!
Title: Re: Small Screw
Post by: basementcalling on August 28, 2019, 07:18:27 PM
@peteski 's rule doesn't seem to apply this thread.

I was not expecting a full page of all on topic posts with that subject line.

Therefore,

[attachimg=1]
Title: Re: Small Screw
Post by: peteski on August 28, 2019, 07:49:57 PM
@peteski 's rule doesn't seem to apply this thread.

And what is my rule?  :?  That every post has to have OT excursion? 
Title: Re: Small Screw
Post by: sd75i on August 29, 2019, 12:48:30 PM
  I needed help with my small problem!
Title: Re: Small Screw
Post by: basementcalling on August 29, 2019, 01:36:30 PM
And what is my rule?  :?  That every post has to have OT excursion?

IIRC, you were the one who pointed out that a thread on TRW would have an off topic post within the first 7 replies to a topic.

Was especially surprised to see lots of restraint on low fruit on this one.
Title: Re: Small Screw
Post by: Rivet Miscounter on August 29, 2019, 03:05:41 PM
[attach=1]
Title: Re: Small Screw
Post by: peteski on August 29, 2019, 04:05:31 PM
IIRC, you were the one who pointed out that a thread on TRW would have an off topic post within the first 7 replies to a topic.

Was especially surprised to see lots of restraint on low fruit on this one.

LOL! I don't remember that, but I'll take your word for it.  After 20K+ posts, it is all a big blur . . .  :D

You're also right that this one was a really low hanging fruit that nobody plucked until you did. But  by now, we are in full OT mode!  8)  All is well on TRW again!
Title: Re: Small Screw
Post by: Maletrain on August 29, 2019, 08:07:42 PM
Tom should hang a rerailer on the bottom of each thread. :D
Title: Re: Small Screw
Post by: basementcalling on August 30, 2019, 02:34:47 PM
LOL! I don't remember that, but I'll take your word for it.  After 20K+ posts, it is all a big blur . . .  :D

You're also right that this one was a really low hanging fruit that nobody plucked until you did. But  by now, we are in full OT mode!  8)  All is well on TRW again!

Peteski, I even tried the search function to find your post, but it doesn't like three letter words like off. Too short to search for. And "off topic" in quotes got lots of weird returns.

Can't believe you don't remember all 20K+ posts you've made on here. :drool:
Title: Re: Small Screw
Post by: narrowminded on August 31, 2019, 01:30:11 PM
Peteski... it doesn't like three letter words like off. Too short to search for.

That has been a problem for me various times.
Title: Re: Small Screw
Post by: sd75i on September 05, 2019, 05:24:30 PM
  I got my small screws today.  I'm going with these.  They are bigger than my small one, but I'll just make a bigger hole for it!  Still might try other places later on!