A chainsaw mill or PortaMill or Alaskan mill is a type of sawmill incorporating a chainsaw, that is used by one or two operators to mill logs into lumber for use in furniture, construction and other uses.
The mill attachment consists of a pair of guide rails which are attached to the bar of the chainsaw. The rails ride for the first cut on a plank or on a metal ladder which is screwed to the log, and then on the previously cut surface of the log, and guide the chainsaw blade through the log at a consistent depth so that planks of a predetermined thickness are cut. The distance between the rails and the bar determines this thickness and it can be adjusted by moving the rails along a post at each end of the mill attachment. During use it is important that the rails extend out past the ends of the log so the cut has support the entire time. 
Small mills use a single chainsaw and can be handled by a single operator. Larger mills use two chainsaw power heads, one on either side of the attachment and these require two operators. This larger style of mill requires a special bar which allows the two chainsaw heads to be attached at either end. The width of the plank that can be cut is determined by the length of the bar, up to 34 inches (86 cm) so for logs having a large diameter, the longer bar is necessary. Also a special chain is designed to make rip cuts rather than the usual chainsaw chain which is for cross-cutting.
For the first cut, a pair of rails or a plank are usually attached to the log to give the mill attachment a reference surface to guide it or other commercially made jigs are available such as a timberjigs. Subsequent cuts are made using the surface of the previous cut as the guide.
The kerf of a chainsaw cut is wide, relative to that of a bandsaw mill or circular saw. This is no problem when cutting a single beam or large timber from a log, but would represent significant waste if used to saw many thin boards.
Alaskan mills are relatively cheap to purchase compared to other types of portable sawmill and are the most portable type of powered sawmill. They are therefore popular with hobbyist woodworkers who have access to felled timber.
- Gehring, Abigail R.. The back to basics handbook: a guide to buying and working land, raising livestock, enjoying your harvest, household skills and crafts, and more. New York, NY: Skyhorse Pub., 2011. Print.
- "Norwood Sawmills PortaMill PM14". Norwood Sawmills. Retrieved 30 August 2019.
- "Home - Granberg International". Granberg International. Retrieved 9 April 2018.
- "How to Use a Chainsaw Mill". Gardenknow. Retrieved 1 January 2019.
- Lopez, Barry. "Mill Lumber With Your Chainsaw". Popular Science Vol. 212, No. 6 Jun 1978, Page 89
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