The highest quality scroll saw blades also use top quality steel and a refined tempering process.
This is important when cutting difficult hardwoods. Hardwoods require a higher number blade, where the blade kerf (width of cut) is larger allowing for easier dust clear out. This type of blade is also useful with oily woods.
The greater blade thickness also results in a longer blade life when used on denser woods. Gummy white pine works best with a skip tooth blade. With more space between the teeth of a skip tooth there’s more efficient dust removal.
When scroll sawing thick wood choose a blade with less teeth per inch. With thin wood choose a blade with more teeth per inch.
A good rule of thumb is to keep at least 4 teeth in the wood at all times on thick wood stock and at least 3 teeth per inch in the wood at all times in thin wood stock.
A scroll saw blade with too many teeth for the job keeps the sawdust from clearing out. The blade soon can get too hot causing the wood to burn. A scroll saw blade with too few teeth will snag the wood. This causes the wood to jump up and down on the table and sometimes become completely out of control.
When scroll sawing delicate fretwork patterns use a high tooth-count blade to maintain better control when sawing. When scroll sawing long gentle curves for outside cuts on a piece of wood, using a blade with less teeth will increase the speed of cutting. The cut will be a little rougher but your sawing speed will increase greatly.
If you are new to scrolling, be conservative with blade selection.
If you are a beginning scroller it is best to choose a blade that has a high number of teeth and is of a heavier gauge steel. This will help to minimize the number of broken blades. It will also make the blade easier to control. For example, a blade with 12 TPI (teeth per inch) will provide good control but will require sawing a little slower than a blade of 8 TPI.
The number given to a scroll saw blade gets larger with the increase of thickness with each blade. A #9 blade is made of much thicker steel than a #3 blade. The thicker the blade steel, the less likely the blade will break. Much more tension and pressure can be applied to a #9 blade than a #3 blade and with less deflection from #9 blade’s vertical path. This is important to consider when increasing cutting speed. Keep in mind that higher cutting speeds can create a need for more sanding.
Scroll saw blade selection requires choosing between blade life, speed of sawing, quality of the finished edge and controlling the saw blade’s path.
The most important thing to remember when trying to control sawing with a scroll saw is to not go too fast. Many retail store scroll saws have small motors with fine blades and are not designed for speed cutting. When sawing too fast on hard woods the blade will walk with a mind of it’s own. Blade breakage is an indication of excessive speed and push against the blade when sawing.
Use this Universal Blade Number chart for choosing the correct blade type based on the wood thickness.