I’m experimenting with drilling holes in rail to attach invisible feeders. The instructions with the drill bit says to run at 3,000 RPM for hard materials and 10,000 RPM for soft material. In this case would nickel silver rail be considered hard or soft?
It’s part nickel, zinc and copper. I would think copper and brass would be considered on the soft side. Do you really have a drill that turns at 10,000 rpm or even 3000 rpm?
I would use the slow speed. 10000 rpm would be ok for plastic maybe brass if you ar carefull. Use slow speed and DO NOT FORCE the bit.
Using a Dremel cordless. Regular drill is too clunky for 1/32" bit.
Bearing in mind there are varying formulations for nickel silver, it is generally considered a hard metal, even replacing stainless steel in some applications.
I would use a slow speed and a cutting lubricant, unless the drill or material supplier indicated otherwise.
CG
CG,
The n/s rail in HO track is definitely a soft metal. A razor saw will cut through it. Try that with steel rail(now, that is hard)!
What I do not understand is why the original poster wants to drill feeder holes in the rail. I just remove the web between two ties and solder the feeder to the bottom of the rail - completely ‘invisible’!
Jim
You can see here:
https://en.wikipedia.org/wiki/List_of_copper_alloys
that the hardness of brass and nickel silver are approximately the same. Note that annealing softens both metals.
As opposed to steel, these metals can only be hardened by work-hardening. Such as being drawn through rollers to make rail. They cannot be hardened by heating and quenching.
Here is a short list of other hardnesses:
https://en.wikipedia.org/wiki/Brinell_scale
Note in particular the number for steel and compare it with the copper alloy numbers.
When in doubt, it’s usually better to go with a slower RPM for drilling. The only downside is that the task takes longer. Which may or may not be a problem for you.
Ed
You did see where I said “experimenting”, right?
I test drilled a couple with a pin vise, which took way too long, but having less than 3 hands I find it far easier to solder a wire into a hole than soldering to the surface of the rail.
I’m also avoiding the new DCC decoders that have solder pads instead of holes in the PCB.
I read all that as yellow brass 55, nickel silver (ASTM B122) cold rolled 170. That is signifigantly harder. I know from experience that brass rod is much easier to cut than NS rail.
CG
At 5,000 RPM, this awesome little bit goes through the base of the rail in less than 10 seconds.
https://www.amazon.com/gp/product/B0019F5AO6/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER
It leaves a nice clean hole that I can bring a solid piece of 22 ga wire up through easily. Only question remaining is how long each bit lasts. At $10 for 3 bits, I’d be happy if they give me a dozen holes each.
Interesting find. Looks like they are out of everything but the 0.5 mm (20 thou) model.
CG
Small tip forceps are available from most anywhere including Micro Mark. They will easily hold a feeder wire against the rail for soldering, or a decoder wire against a solder pad. It’s not going to fall off, and unless you try to swing the loco around by the wires attached to the decoder, it won;t pull off either. COnsider most electronic components on those very same decoders are surface mounted, no holes to be found. They certianly don’t just fall off from use, and they aren’t all that easy to pop off with just your fingers.
I’d consider drlling the rail for large sizes - maybe O, certainly Large Scale. With large scale there are even rail clamps that go through drilled holes just liek prototype joint bars, as well as the kind that just clamp against the rail.
–Randy
You are quoting the ANNEALED brass hardness of 55, and the COLD ROLLED hardness of nickel silver, which is 170. Cold rolling typically hardens metals.
You should have compared either the ANNEALED numbers (55, 70) OR the COLD ROLLED numbers (180, 170).
I would recommend the latter, because model railroad rail is, yes, COLD ROLLED. And, in that case, the brass is slightly harder by 10 points. Our rail, brass or nickel silver, is left un-annealed because:
(1) It takes another step. Which costs the manufacturer money. Especially so, since model railroad rail is a small-production process.
(2) If the rail were annealed, it would bend easier. Which is a bad thing if you are trying to lay straight track.
As an experiment, I just did the annealing process on some formerly valuable nickel silver rail. It became MUCH easier to bend. Thus corroborating my assertion that our rail is cold rolled.
I can think of two ways to explain your experience:
One is that the brass rod you were cutting has been annealed.
Or, two, you found it harder to cut because the cross-section is complex, and thus difficult to saw in a smooth consistent manner.
Ideally, you would be sawing both brass and nickel silver rail for the comparison. I have done so, and I found no difference.
Ed
You are right, I misread the chart.
But regardless of NS rail’s hardness relative to cold drawn brass, numerous web sources refer to it as hard, which was the original question.
CG
On Carl’s interest on making invisble feeder attachments:
I have been doing this for quite some time with Code 83 NS rail. I bend my feeder wire into an L, with about a 3/16" tail. I solder this tail lengthwise onto the rail bottom. I spot a hole to run the feeder through to underneath the layout. If there is a tie in the way, I cut a notch.
I have also attached feeders to the frog assembly, closure rails (if necessary) and to the points of switches for positive electrical feed.
I have had no problems. Yet. My only anxiety would be for the points, where there is movement. I have allowed a good bit of clearance under the rails for wire movement; and, so far, have had no failures.
IF I had a failure on the points, I would consider drilling a hole. Or I might possibly use stranded wire, though I suspect the solder might run down the wire and “solidify” it.
Ed
If you got some Navel Brass you would find it a lot harder than regular brass.
The whole point of this thread was the OP’s query so he could decide what drill speed to use.
The holes are drilled. Whatever speed he used was a success, it seems. [;)]
CG
I use the two hand method to attach feeders. Tin the side of the rail. tin the end of the feeder. Hold the end of the tinned feeder to the tinned rail. Touch with the hot sldering iron. Hold a few seconds until cool.
But if drilling, add some lubrication to make the bit last longer.
Martin Myers
If you add lubrication, it would be wise to remove it from the part before soldering. That alone might convince me NOT to lubricate the bit.
I drill a fair amount of steel, and my aversion to cleaning off the lubricant keeps me from applying it. If I add up all the time it takes to apply and clean up lube, that’s a LOT more than the cost of a drill bit. Which I really should be re-sharpening, anyway.
Ed
I’ve got some of these left over from the 70’s. I find they act as a heatsink when used as you suggest and amplify the flaws in my soldering skills.
I’m curious why if a hole is good for large scales, why not for HO?
5,000 RPM. That’s the slowest speed on my Dremel. And yes, I have declared victory.
I have been taught this probably a dozen times over the years and I am embarrassed to say my success rate is still only abo