Coupler box fasteners


JP Barger
 

Dear Jim et al, Thanks for your message about fasteners I use to secure
coupler boxes to car underbodies. I use a series of Japanese metric
miniature machine screws. The original requirement to go in this direction
came from using American Standard #2-56 round head screws, whose heads stick
out so far as sometimes to interfere with proper free rotation of the outer
wheel axles, causing ugly marks on the axles, and derailments to boot. In
addition, the American screws are UGLY all the way to the bone. The Japanese
screws are stainless steel, originally designed for Japanese camera
bodies, and now used in miniaturization of much small hardware. American
standard pan head slotted or Philips head screws could be substituted, but
the heads are SO large. Their advantage is that the axle rubbing problem
goes away. Many of the brass models use metric screw mounting, but a
minority have blackened screws.

The series of screws I employ has Philips pan heads, 1.4, 1.7 and 2.0mm in
thread diameter. Taps for these are available from any serious metric screw
dealer. The head diameters for these screws range from 2.0 to 2.5mm. The
2.0mm head diameters are called type1; the 2.5mm heads are type 3. These
screws are blackened with a satin finish. Thus, since most plastic
underbodies and coupler boxes are black, anyhow, you're relieved from
painting the screwheads. The use of these screws has made my underbodies so
much neater. Since I like to run longer trains, I need extreme reliability.
Thus every coupler box is first applied to the car underbody with a small
wipe of Goo, or its equivalent, and then screwed down, as well. The Goo
application prevents coupler box rotation; the alternative is to use two
1.0mm screws, applied through the ears on the Kadee box.

My screw collection came mostly from Metric Screw in Wakefield, MA. Their
phone number is 781-245-4950. I believe their stock of these screws is
exhausted. They may need to special order them. Or you may need to find a
new source. If you do, please let me know. Thanks. Another source, from
which I have a lot of screws in the aforementioned sizes, is NWSL. But the
last time I looked, their screws were shiny finish stainless. The heads will
need to be painted, and a screwdriver will remove the paint gradually. I
wish they would go for black finish. Small metric screws can be bought in
Tokyo from small electronics parts suppliers, if you ever go there. I've
done it, but it was a long time ago.

By the way, the blackened 1.7 & 2.0 screws come in lengths one mm apart, and
in the shorter ones, only a half mm apart. Very handy for open and tank
cars. No cutting and filing screws to length! I need to add that when I'm
working with WOOD bodies, using the normal tap drills, I drill and tap just
like I was working with metal. I've never had any trouble with the metric
screws stripping, loosening or falling out of the wood; the same applies
with plastic bodies.

Something I would like is a source of BLACKENED #2-56 stainless screws,
Philips pan head, satin finish, for truck mounting. If you find a source
for these, I'd also like to know.

Best regards, JP

Join {main@RealSTMFC.groups.io to automatically receive all group messages.