Machining nickel silver

[SteveCrow]

Hello everybody, this is my first post on this forum.

 

Can anybody tell me what nickel silver is like to machine on a very small scale?  Basically, does it grab drills and how is it to turn and mill?

 

I have a watchmakers lathe and a very small mill but only really use brass and silver steel.

 

I know nickel silver is great to solder but i would like to know more of its characteristics before I commit to using it.

 

Many thanks

[oily]

Hello everybody, this is my first post on this forum.

 

Can anybody tell me what nickel silver is like to machine on a very small scale?  Basically, does it grab drills and how is it to turn and mill?

 

I have a watchmakers lathe and a very small mill but only really use brass and silver steel.

 

I know nickel silver is great to solder but i would like to know more of its characteristics before I commit to using it.

 

Many thanks

I'm sure engineers will tell you it depends on the code of the brass or N/S you use, and I'm sure they are correct. But as a layman with no engineering training I have used both for many years and find them quite similar to machine, in fact I prefer N/S as tiny parts made in it are stronger. Brass can end up rather soft and eaily bent if left very thin. I also get a better finish on N/S, it solders and paints better, and it looks more like steel on a model.

I'm sure others will take an alternative view, as I say I've no engineering training, I speak only from my experience.

Oli

[Yorkshire Square]

Nickel silver is the defacto metal for 2mm Association etched kits. The only brass ones I'm aware of we buy in from third parties. I believe that this is because it is fairly hard compared to brass. However for turning or castings we tend to use brass.

 

What do you propose using it for?

[SteveCrow]

Nickel silver is the defacto metal for 2mm Association etched kits. The only brass ones I'm aware of we buy in from third parties. I believe that this is because it is fairly hard compared to brass. However for turning or castings we tend to use brass.

 

What do you propose using it for?

I want to model some tubular steel struts.  This will involve 1mm to 2mm rod drilled at the end to accept location pins and milled at angles to create sockets for other rods.  A bit hard to explain.

 

I v'e been doing the same thing with brass for a while but I want to use NS because, as the post above mentions, it looks more like steel and is easier to solder.

I'm sure engineers will tell you it depends on the code of the brass or N/S you use, and I'm sure they are correct. But as a layman with no engineering training I have used both for many years and find them quite similar to machine, in fact I prefer N/S as tiny parts made in it are stronger. Brass can end up rather soft and eaily bent if left very thin. I also get a better finish on N/S, it solders and paints better, and it looks more like steel on a model.

I'm sure others will take an alternative view, as I say I've no engineering training, I speak only from my experience.

Oli

Thank you, that sound encouraging.

[SteveCrow]

Hello everybody, this is my first post on this forum.

 

Can anybody tell me what nickel silver is like to machine on a very small scale?  Basically, does it grab drills and how is it to turn and mill?

 

I have a watchmakers lathe and a very small mill but only really use brass and silver steel.

 

I know nickel silver is great to solder but i would like to know more of its characteristics before I commit to using it.

 

Many thanks

[Roy Langridge]

Very dependent on the alloy. Varies from free cutting to very "grabby". Do you know what percentage nickel it is?

 

Roy

[SteveCrow]

Very dependent on the alloy. Varies from free cutting to very "grabby". Do you know what percentage nickel it is?

 

Roy

No idea on the percentage. It will be really small stuff - 1mm to 2mm rod from Eileen's Emporium or similar.

 

I'm using brass rod at the moment but I'd prefer NS for a few reasons.

 

I'd heard it could be a bit grabby, that's why I'm beig cautious about using it.

 

Steve

[garethashenden]

I'm sure engineers will tell you it depends on the code of the brass or N/S you use, and I'm sure they are correct. But as a layman with no engineering training I have used both for many years and find them quite similar to machine, in fact I prefer N/S as tiny parts made in it are stronger. Brass can end up rather soft and eaily bent if left very thin. I also get a better finish on N/S, it solders and paints better, and it looks more like steel on a model.

I'm sure others will take an alternative view, as I say I've no engineering training, I speak only from my experience.

Oli

Nickel silver is often considered to be a brass alloy. Brass is copper and zinc, nickel silver is copper, zinc, and nickel. As such, they are broadly similar in their machinability, although NS is slightly harder.

[ian@stenochs]

Hi Steve,

Nickel silver is a bit harder to drill than brass but it's other properties make up for that. I always make smokebox doors from thick sheet ns and turn them up on the lathe. All my loco platework is ns either profile milled on my Taylor Hobson or sawn out with a piercing saw. I work in 7 mm scale so the bits are a bit bigger than yours. Only thing I do which is different from machining brass is to use a little cutting fluid on the cutters and saw blades.

As for soldering it is so much easier than brass which must make assembling small components in 2mm very tricky as the hear spreads so quickly.

Ian.

[ian@stenochs]

Hi Steve,

 

I use nickel silver almost exclusively. It is a bit more difficult to drill than brass but it's other properties far outweigh that.

 

I use ns sheet for bodywork and cut it to shape with my profile miller or piercing saw. A wee touch of cutting fluid helps the saw along and it does non harm on the milling cutters either. I turn thick sheet ns for smokebox doors on my lathe and as long as the tool is sharp and the speed right I get a very good finish. As I work in 7mm scale so the bits are a bit bigger than yours. However soldering small brass parts in 2mm scale must be very difficult given the way brass conducts heat.

 

Ian.

 

[PenrithBeacon]

I don't have a lathe so my experience of 'machining' nickel silver is limited to drilling the stuff. I decided I needed to know what the cutting speed of the material is to set the rpm of my drilling machine. So far so good. The problem was that there doesn't seem to be one published on the web. Because of this I decided to use the cutting speed of hard brass and it worked like a dream.

 

Now there is an additional problem; I made a note of the cutting speed but now I can't find it, sorry. I suppose a search on the web would provide the answer.

[Donw]

It is a bit two edged for example NS is harder to form than brass but that also makes it hold a shape better and be less subject to dents.  That is probably why it tends to be favoured for chassis parts by some kit manufacturers that use brass for the bodywork. In 2mm where thinner metal is often needed the extra rigidity can be very useful. I have not noticed much difference in soldering. The better adhesion of paint on NS is widely accepted. I think as you are planning to make small diameter struts the extra rigidity may be useful.

Don

[bertiedog]

Mostly nickel silver behaves like brass for machining, but it does alter in a couple of respects.

First it work hardens, so very small diameter drills under about 1mm can break in deep holes in solid metal, it is best to add cutting oil or olive oil to stop the breakages. The same applies to tapping into deep threads, use oil.

Ordinary jobbers drills tens to snatch in nickel silver, especially in thin plate, use a centre drill and work up to the final size, or back off the drill; grind to 90 deg or negative by a degree or more.

Spade tipped drills also work better with nickel silver.

 

Stephen

[hobbyhorse]

Like a lot of metals Nickel Silver comes in lots of different grades and unfortunately most of the sheet work that model supplies stock isn't the best for machining. Some trade metal stockist can supply a grade that is leaded which will machine like brass, one such is Columbia Metals, I was able to get sheet material upto 1/8th thick and bars upto 3 inch diameter. One of the problems I faced with some of our castings (Hobbyhorse) is that we needed to machine the nickel silver castings, and our caster provided a mix that is machinable.

[Miss Prism]

I made a note of the cutting speed but now I can't find it, sorry.

 

That would be a very 'useful to know'. (Even if controlling one's drill speed is a bit arbitrary.)

[Roy Langridge]

That would be a very 'useful to know'. (Even if controlling one's drill speed is a bit arbitrary.)

Drilling speed is different depending upon the size of the drill, the alloy and drill type.

 

Looking at the Nickel Silver speeds for my carbide tipped drills it says SFPM is 125 to 190. RPM = SFPM*3.82/Drill Diameter (in inches).

 

Roy

[Izzy]

To try and answer your basic question, how easy is it to work, I would say that while free cutting stuff is available for machining, most sheet and small drawn wire from outlets like Eileen's is of the harder variety, (especially the straight drawn type rather than coiled, some of which is very soft), and this will tend to 'grab' at drill/end mill flutes, especially when breaking through holes/slots etc. and particularly with the smaller sizes such as 0.3/0.4/0.5mm. Though it sounds crude spit is a very good lubricant.

 

Izzy

[£1.38]

Another option would be to use combinations of metal tubing and rod. These go down to as small as 0.3mm at least and come in sizes that fit well within sizes above them. That way, the tube would eliminate the need to drill the ends of the rod

[SteveCrow]

Another option would be to use combinations of metal tubing and rod. These go down to as small as 0.3mm at least and come in sizes that fit well within sizes above them. That way, the tube would eliminate the need to drill the ends of the rod

I have been using that microtubing stuff for a while now and very useful it is too. The problem is, if you need to step down a bit (say from 2mm od to 0.8mm id) you need multiple sections of tube which can work out quite expensive.

[SteveCrow]

To try and answer your basic question, how easy is it to work, I would say that while free cutting stuff is available for machining, most sheet and small drawn wire from outlets like Eileen's is of the harder variety, (especially the straight drawn type rather than coiled, some of which is very soft), and this will tend to 'grab' at drill/end mill flutes, especially when breaking through holes/slots etc. and particularly with the smaller sizes such as 0.3/0.4/0.5mm. Though it sounds crude spit is a very good lubricant.

 

Izzy

Thank you, I will be using hard drawn rod and drilling between 0.5 and 1mm to a depth of about 3mm. As suggested above, I can make some spade drills and I have some tiny drills ground for brass.

[Izzy]

Thank you, I will be using hard drawn rod and drilling between 0.5 and 1mm to a depth of about 3mm. As suggested above, I can make some spade drills and I have some tiny drills ground for brass.

 

Forgive me, but I would be wary of using brass rake angle cutting tools, they either won't cut very well or will blunt quickly. Hard N/S is quite abrasive and needs sharp cutting edge tools.

 

Izzy

[SteveCrow]

Thank you for all your informative replies.  Weighing things up, I'm going to stick to using brass for parts that need fair bit of machining and NS whenever I can get away with it

 

Steve

[bertiedog]

It is not the sharpness that affects brass and nickel cutting , it is the front rake of the cutting edge, which with most common or jobbers drills in HSS steel are set for drilling into steel, with a considerable cutting rake. this rake can cause the work to snatch as the edge gets a good bite, and pulls down the tip into the metal.

With copper and brass it enters quickly and snatches, but with Nickel Silver it enters quickly, and then snatches into the work hardening metal, resulting in a sudden break.

Backing off a rake on a drill is not for the faint hearted, it does involve a lot of practice. The easiest tool to do it is the Dremel motor toll type, with  fine cutting disks used. The disc is about a mm thick and will fit the tips of drills down to about 3mm or even 2.5mm. and is applied to the front cutting edge at right angles. This reduces the rake to zero, but still leaves a sharp cutting edge. The drill will no longer snatch into the metal. The accuracy of the point grind is not affected by altering the rake, so that the drill will still drill to true size.

For really tiny drills the rake can be rubbed down with an abrasive stone or diamond files, under a magnifying glass if possible.

 

To totally prevent snatching negative rake can be used, this still is a dead sharp edge, but drags on the metal preventing a rush forwards. This is used mainly for clockmaking and into thin metal sections, where a snatch would destroy expensive work.

 

A spade drill is usually home made, a rod with both sides ground way to leave a screwdriver like tip, which is then ground to the usual angles for a normal drill, but it naturally has zero rake.It will not snatch into holes in thin metal.

 

 

On cutting speeds it is up to you, the quoted speeds are for max production in a factory and lower speeds always work, so the home mechanic should disregard the tables and use slower speeds, less risk of drill breakage etc, less wear, and lower noise as well. Lathes are often used far to fast by amateurs or the new users, it should be at low speeds that the best finishes are produced.

 

The key to all machining is that the cutting edge must be dead sharp at all times, no excuses, sharpen the tools correctly!

 

Stephen

[SteveCrow]

It is not the sharpness that affects brass and nickel cutting , it is the front rake of the cutting edge, which with most common or jobbers drills in HSS steel are set for drilling into steel, with a considerable cutting rake. this rake can cause the work to snatch as the edge gets a good bite, and pulls down the tip into the metal.

With copper and brass it enters quickly and snatches, but with Nickel Silver it enters quickly, and then snatches into the work hardening metal, resulting in a sudden break.

Backing off a rake on a drill is not for the faint hearted, it does involve a lot of practice. The easiest tool to do it is the Dremel motor toll type, with  fine cutting disks used. The disc is about a mm thick and will fit the tips of drills down to about 3mm or even 2.5mm. and is applied to the front cutting edge at right angles. This reduces the rake to zero, but still leaves a sharp cutting edge. The drill will no longer snatch into the metal. The accuracy of the point grind is not affected by altering the rake, so that the drill will still drill to true size.

For really tiny drills the rake can be rubbed down with an abrasive stone or diamond files, under a magnifying glass if possible.

 

To totally prevent snatching negative rake can be used, this still is a dead sharp edge, but drags on the metal preventing a rush forwards. This is used mainly for clockmaking and into thin metal sections, where a snatch would destroy expensive work.

 

A spade drill is usually home made, a rod with both sides ground way to leave a screwdriver like tip, which is then ground to the usual angles for a normal drill, but it naturally has zero rake.It will not snatch into holes in thin metal.

 

 

On cutting speeds it is up to you, the quoted speeds are for max production in a factory and lower speeds always work, so the home mechanic should disregard the tables and use slower speeds, less risk of drill breakage etc, less wear, and lower noise as well. Lathes are often used far to fast by amateurs or the new users, it should be at low speeds that the best finishes are produced.

 

The key to all machining is that the cutting edge must be dead sharp at all times, no excuses, sharpen the tools correctly!

 

Stephen

I use a diamond hone for this. Drills down to 1mm are doable. Hold the drill in a pin vice and keep the hone parallel and level to the drill. Just a few careful strokes does it. Like a lot of tiny stuff, you can feel, even hear, more than you can actually see going on.