A Few Questions About The Prewar 400E ????

Here is a picture of the missing screw hole

there are, if memory serves 5 screws , one in smoke stack, 2 under fire box skirts  and 2 at the cab corners. Have to open or remove boiler front also as latch will hold boiler on. 6-32 screws all around regular head

Not familar with your engine and tender. Lionel also used 4-36 screws here and there prior to WWII. So, if you find some places where the 6-32 screws are too big, you MIGHT need some 4-36 ones.

Be aware that 4-36 screws are more or less obsolete, so most hardware stores don't have them. Lionel parts dealers do.

If a screw isn't going in smoothly with only minor resistance, you may have the wrong thread or the screw might be cross-threaded.

4-36 were used a lot in pick up roller of passenger cars and otherwise infrequently. 4-40 in O gauge and 6-32 in standard gauge. I have taps for all of these sizes so can freshen the threads. The best source for screws I have found and the most cost efficient is Mcmasters Carr. Carry all sizes including fillister head 4-40 used in prewar O.

I have taps for all of these sizes so can freshen the threads.

Me too. I also have a couple of different style screw pitch gauges to check.
One is a metal plate with different sized threaded holes. You test fit the screw to identify it.
And the other has an assortment of blades with varying teeth. You match the teeth against the threads to get the thread count. I normally use the plate.

I cannot tell a 4-36 from a 4-40 just by eye any longer.

Menards has a great sale on reading glasses, 3 for $9 helps immensely !!

Also to cut to length, most wire lug crimpers have threaded screw cutters on them that make trimming screws to length easy and reshapes thread after wards as well.

stevin posted:

Here is a picture of the missing screw hole

One can only marvel at a picture of a missing hole.😊

C W Burfle posted:

I have taps for all of these sizes so can freshen the threads.

Me too

I cannot tell a 4-36 from a 4-40 just by eye any longer.

Don’t fret, C.W. Even Superman’s X-Ray Vision degraded to Ultraviolet Vision as he aged.

Most ALL pre war "O" & "STD" were 4:36 or 6:32.  Most all trim pieces were 4:36, including bells, whistles, pantographs,  "O" motor mounts to frame, steam boiler fronts, & body mounts.    Std. ,most common was 6:32 motor mounts, frame mounts, gear plates. Body mounts 4:36 or 6:32. Most std. car trim were 4:36, there again same for bells, whistles and pantographs.  As far as I know, 4:40 was a post war item.  Harry 

Jagrick posted:

Also to cut to length, most wire lug crimpers have threaded screw cutters on them that make trimming screws to length easy and reshapes thread after wards as well.

I still do it the old fashioned way. Thread on a nut before cutting (heavy lineman's pliers or hacksaw), dress with a file, remove nut.

Once in a while I use a die to clean up the threads. 

I like to chamfer the edge of the thread too.

I use a similar set of Klein strippers, one for small stuff and one for larger. I don't think mine crimp, I have a separate crimper.

I'll have to see what they have.

They don’t have to be the name brand version. I picked up my set at Menards

Harry Henning posted:

Most ALL pre war "O" & "STD" were 4:36 or 6:32.  Most all trim pieces were 4:36, including bells, whistles, pantographs,  "O" motor mounts to frame, steam boiler fronts, & body mounts.    Std. ,most common was 6:32 motor mounts, frame mounts, gear plates. Body mounts 4:36 or 6:32. Most std. car trim were 4:36, there again same for bells, whistles and pantographs.  As far as I know, 4:40 was a post war item.  Harry 

 I know the body mounting fillister head screws are 4-40.