The chainsaw you choose has a big influence on how your chainsaw milling goes – after the milling attachment, the saw is probably the most important part of your setup.
It is common knowledge that chainsaw milling takes a big saw. But how big exactly? Why? Can you get by with a smaller saw?
In this article, I am going lay out the basics of chainsaw sizing for milling. In a nutshell, chainsaw milling is power-intensive and best done with a large saw with more than 90cc of engine displacement. Lower-powered saws can also be used for small logs, but require more careful operation and are prone to overheating.
Having chainsaw-milled with saws from a 1.5 kW battery saw up to a 7 hp gas saw, I share my milling experience with you in this article.
We first rank the saws by engine size (cc.) and talk about why a big engine is important in milling. Then we see which log size can you mill with each cc saw and finish by analyzing what exactly makes chainsaw milling so power-intensive.
Bigger mills better
The high power draw and long cutting times of chainsaw milling call for a saw with a big engine. The best saw for chainsaw milling is therefore the biggest you can afford.
If money is no object, I suggest you go for a 90cc to 120cc saw. These saws are top-of-the-line professional logging saws built for heavy duty logging, and will give you the smoothest milling experience But be prepared to pay for it: new 90cc+ saws typically cost $1000 to $2000.
The next best thing is a 70cc to 80cc professional forestry saw. These saws will give decent milling performance up to about 25″ logs and cost you a lot less, coming in at around $1000 new.
The smallest saws that I would recommend for milling are 60cc Farm&Ranch models. Suited mainly for small logs under 20″, the 60cc saws are really under-powered for any milling. But with enough care, they just get the job done, and are more affordable (~$600), lighter and handier for all-around use than the big saws.
The table above summarizes the milling performance and price range of different chainsaw sizes. It also gives you specific Stihl and Husqvarna models as an example. Also check the CC. vs. log size table below.
Big engine benefits
But why is a big engine so important for chainsaw milling?
The main advantage a large-displacement engine like a 90cc or a 120cc brings in milling is high torque.
First, a big saw with plenty of torque mills faster: you are able to keep the chain speed up and many teeth cutting at the same time even with a log-wide contact with wood.
Second, milling is easier to control with a big saw: the plentiful torque reserve means that the saw will not stall as easily as small saws.
Cutting with this saw is easy: give the saw full throttle and enough push to keep the RPM around peak torque (~6000 rpm).
Big engine drawbacks
The main disadvantage of big saws is price: for new 90cc+ Husqvarna or Stihl, you have to pay more than $1000. These are professional saws, at a professional pricepoint.
Another obvious drawback is the size and weight. The big-engine top end saws weigh from 15 lb. to 23 lb (powerhead only), which makes them much less ergonomic than the ~10 lb. homeowner or Farm & Ranch saws. Although the 90cc to 120cc saws are great, they’re clumsy in most everyday use.
In other words, the best saws for chainsaw milling are pricey and best only for milling.
Saw CC. vs. Log diameter
Biggest is best, but what if you do not want to invest in a $1000+ chainsaw just for milling? How much milling could you do with the lower-powered saw you have?
The truth is that also lower-powered saws can be used in chainsaw milling: a 60cc, a 50cc or even a 45cc saw can be used. You just have to be more careful and, most importantly, settle to smaller logs.
Below is a table of suitable log diameters for milling vs. chainsaw engine size (in cc.). The middle column is Granberg’s recommendation for their Alaskan chainsaw mills.
Personally I find Granberg’s log diameters very optimistic. I have therefore included my own more conservative guidelines in the last column.
Milling with smaller saws
If you choose to mill with an under 90cc saw, there are many things to consider and watch out for. This is an important topic so I have assembled the advice to a separate post.
Why is milling hard on the saw?
Chainsaw milling puts exceptional demands on the power output capacity of your saw. But why is this so, exactly?
First of all, milling requires a lot of power. This is down to two factors: long contact length and cutting the wood grain.
Factor 1: Long contact
If you mill straight without seesawing – as you should – your saw chain will contact the wood over the whole log thickness. This means that unusually many teeth will cutting and taking up power at the same time.
In cross-cutting, by contrast, varying the cutting angle is done intentionally to reduce the contact length, and tilting the saw up and down is a part of proper technique.
Factor 2: Cutting the grain
Due to the way it is constructed, a chainsaw chain cutter actually cuts across the grain in milling. Unlike the typical saw blade (band saw, hand saw) which rips between the wood fiber, chainsaw chain cutters rip by trimming wood fiber with their top plates over and over again.
This continuous cutting of wood fiber is hard and makes milling tougher for a chainsaw than cross-cutting is. That is, it is harder to mill a log than buck it.
Factor 3: Cut duration
The second factor that makes milling hard is time: milling cuts are long. While cross-cuts usually take some seconds or tens of seconds at most, a single milling cut may take many minutes.
This means that instead of seconds, your saw will be working at high power levels continuously for minutes at a time.
Consider used saws
This is why I highly recommend used saws for milling. You can find an old big Husky or a Stihl in good condition for less than half the price of the new saw.
Old models may lack some modern comfort features, but you probably won’t need them in milling anyway. Only torque counts.