2-56 Screw vs O Gauge Coupler Boxes.

[Last Chance]

 Ok, Thank you everyone. It worked precisely for the bolts. I am happy for the assistance.

 I was able to complete the installation on the bolted coupler boxes without too much issues and some lessons learned.

[servoguy]

Here is a link to a tap size chart giving the drill size for the tapped hole and the clearance hole size. Lonewolf is right about the drill sizes. If you drill a hole with a #43 drill, the screw will go right through it. If you are drilling and tapping metal, put a little WD-40 on the drill and tap and it will make a much cleaner hole and make drilling and tapping much easier. http://www.physics.ncsu.edu/pearl/Tap_Drill_Chart.html Bruce Baker

[lonewoof]

 Close, but no cigar.

#43 is a CLEARANCE size for 2-56; that means a 2-56 screw will slide through a #43 hole (think of the hole in a truck bolster, that you push a screw through).

#50 is a TAP drill size for 2-56; that's the size you'd use if you were going to tap a hole. Incidentally, a 1/16" drill is very close, and probably easier to find than the numbered drill.

 

/Lone

 

[Last Chance]

 Hello everyone. I have been accustomed to HO Scale for a long time, but never forgot the O Gauge I grew up with.

 2-56 screws were used for truck mounting in HO Scale and now they are used for O Gauge Kadee Coupler box mounting. Something clocked me mentally when I realized just how large the hardware is getting to mount the trucks to the O gauge.

 Anyway, I have a set of 2-56 screws, wrench for it (Hex machine screws from Walters) and a tap tool to make new hole for these 2-56's to screw into. Now I have a question. What drill size do I need to "Start" a hole just enough for the Tap drill tool to bite into and make a fresh hole with threads ready to accept a 2-56 machine screw?

 A chart provided with the 2-56 tap/drill set shows this following:

 Size 2-56 (Also has 1-72, 0-80, 00-90 but focused on 2-56 for today)

Rod Dia .085

Tap drill no. .50

Clearance drill no. 43

Screw dia. .085

 Each of the other sizes I mentioned earlier have their own numbers and if anyone needs them, let me know and I will give it.

Looking at the chart I would think I want to use a Number 43 drill bit to make the hole so that the tap tool will enter and create a new 2-56 hole ready to take screws.

Did this make sense or am I in need of tap/drill school all over again? I took this knowledge decades ago when working and learning about engines but it has all rusted and these numbers I am looking at needs to be refreshed and double checked.

I intend to install a Kaydee 805 coupler box onto a O gauge caboose hopefully after learning what it will take to do it right with 2-56's

In the past I would stick the strongest adhesive and slap the thing on there, but having gone through a three rail to two rail conversion, I feel I must complete my punishment by over engineering and working down to the last detail as possible.

 

Any advice would be appreciated.