.Below is a close up of the tip of my 16" carving bar, it has a radius of about 12mm (quarter tip). The 12" bar has a radius of about 8mm (dime tip). These bars are made in Canada and are very well engineered. They are made from one piece of steel (rather than being laminated), the rails are triple induction hardened and the tip has a sizable section of stellite welded into it (as can be seen in the photo). They are solid nose bars and the gauge of the bar groove is 0.050". When first put to use it is advisable to run the chain relatively slack (i.e.hanging down with the tie straps just off the bottom bar rails) compared to the standard tension used with a solid nose bar. Initially there is a tendency for the bar to heat up a lot while both bar and chain are bedding in. This causes the chain oil to burn black which is then thrown off onto the carving making black lines. This normally passes after a few days of carving, then the chain can be run a little tighter (as a rough guide the bottom of the tang in the middle of the chain, hanging from the bottom of the bar, should be nearly visible). The black lines get fewer as the bar and chain bed in (as long as the saw oiler is working efficiently). The chain should be very easy to pull round the bar. It does very little harm for the bar tip to heat up to and turn blue as long as it isn't prolonged. This often occurs in heavy use.

The carving bars come in a variety of sizes and normally with three different types of tip. Smallest is about 8" useable length longest about 24" (there may be other sizes available from specialist suppliers). The three types of tip are "dime", "quarter" and "toonie",

Dime tip. The smallest radius. This is best being reserved for the final fine detailing work using the shorter bars. They don't hold up well to being used on overpowered saws or for heavier cutting. The small tip means that there is a lot of heat and friction built up there in heavy use, this can lead to early wearing out or stiffening up of the chain. The bar nose can also develop undue wear on the inside of the rails, even to the extent of the chain forcing the bar rails apart.

Quarter tip. Next size up. Where the "dime" compares to the size of the American coin of that name, the "quarter" compares to the size of that particular coin. This bar is more suited to a bit heavier work. The larger tip radius means that there is less concentration of heat as the load of the chain is spread over a longer length of bar rail. The tip of the bar is still small enough to use without having to worry overmuch about kickback. Just not quite as good as a dime for fine detail.

Toonie tip. Named after a Canadian coin of the same radius, a bit bigger than the "quarter"tip. This type of bar is a very good substite for a standard sprocket nosed bar. It has a small enough radius to deliver very little kickback. The fact that it is a solid bar and has no sprocket means that it will take a lot more punishment than a sprocket nosed bar. Often used for general roughing out and even levering off partially cut sections of timber. Chain still has to be run a little loose compared to a sprocket nose bar. The bar is still .050 gauge so the chains mostly used on it (3/8 low profile, and 1/4 pitch both .050 gauge) are just a bit more fragile than the standard .058 and .063 gauge chains normally fitted to mid range saws. It is not unusual to snap, even a new chain, in hard timber or when the chain gets nipped in a cut.

Sprocket tip carving bars. These are made by an Australian company GB Manufacturing Pty Ltd. They are not very generally available but if one comes across one of these bars there are a few things to be aware of. The chain has to run snugly on these bars, not slack as in the usual carving bars. If run slack there will not be enough oil getting to the sprocket nose and it will fail. There is noticeable kickback with these bars, not dangerous, but annoying. It can jump in a cut causing damage to surrounding areas. It is also very fragile, the sprocket is very small and won't take a lot of heavy cutting. The company make an excellent range of other bars (including carving bars) as well.

The choice of chain is also important with these carving bars. Firstly, the chain must be of .050 gauge. None of the .325 pitch chain I have tried so far seems to work very well on a carving bar, although there may be some out there that does work. The dime tips will only take 1/4"pitch chain. The “quarter” tips and the “toonies” will work with 3/8”pitch low profile chain, toonies in particular. It is also very important not to use “consumer” chain. This is the chain that is always supplied to saws that are generally sold directly to the public. This chain has an extra element built into it called a bumper tie strap. This prevents the bar of the saw from being able to cut at the tip, which cuts down on the risk of injury from kickback. The Dime tips will run on 1/4"pitch chain generally available from either Oregon or Sthil.
Some mid-range saws are very difficult to equip with either a 1/4" or 3/8" pitch sprocket. They only come with .325 pitch sprockets. Some of the professional saws will carry a splined clutch drum that will take different pitch rim sprockets.