Can/should I use 3-in-1 oil to lubricate when I do the initial drill hole for a 2-56 screw? I have an Athearn engine with a recessed partial hole in each end coupler plate that I need to drill out for a 2-56 screw for attaching a Kadee coupler. Should I do the same for the manual (hand) tapping? Cedarwoodron
Only if you want your tools to last!! [:-,]
Any kind of light oil will do (personally I use Dexron 3 ATF) It will allow the cutting faces to stay sharp longer, plus make the job easier. It only takes a drop or two. I’ve got taps that are 20 years old, and still work great!
Are you drilling through plastic or metal? A metal working friend of mine recommends different types of lubrication for different types of metal. Never asked about plastic. Don’t know if I would use anything if drilling plastic with a pin vise.
Good luck,
Richard
Generally a light oil helps the cutting of the tap hole(#50 drill bit for a 2-56). I use what is ‘handy’(Labelle #107). If you are drilling into plastic, make sure the oil is ‘plastic compatible’. For the actual cutting of the threads with the tap, I use either the light oil, or ‘bees wax’. The key to not breaking a tap is to back it out often and clean out the flutes in your tap. I have broken two 2-56 taps in about 40 years - all because I was impatient.
Jim
Gidday, without over complicating the issue by mentioning drill and cutting speeds, the basic rule of thumb lubrication I use for drilling and tapping is; ordinary car engine oil for steel, kerosene for aluminium, so your use of 3 in 1 oil is perfectly acceptable for what you are doing.
For tapping start the tap with a steady even pressure,as soon as the tap is started it will feed itself through. Turn the tap half a turn clockwise, then back off one quartet of a turn to allow the tap to clear. Disclaimer: I am lead to believe that for some new types of taps backing off is not necessary and in fact may damage the tap. Mine are too old for that.
Cheers, the Bear.
I have a Kadee drill and tap set for 2-56 screws, but read the instructions AFTER posting my question, but I’ll offer my thanks to you guys who responded. I followed Jim B’s advice on the tap portion of the process and was patient, backing the tap out after three or four turns, as it slowed, and was rewarded with a perfect 2-56 threaded hole- which I promptly used to mount my Kadee couplers on the frame. The thing I guess I am confused about is: I understand the first drill bit, making the basic hole and the tap cutting the thread courses, but Kadee included a second larger bit, for “clearance”, which I did not use. I cleaned the threaded hole, and was easily able to screw the 2-56 screw into it. That second bit seems unnecessary… Cedarwoodron
The “clearance” bit is not used when tapping a hole
.That is for drilling a hole that the screw will go through cleanly…or “clear”
Most likely a #41 or #43