Using a scroll saw blade sizes chart is the easiest way to figure out which teeth-per-inch count matches the thickness of the wood you're working on. If you've ever tried to force a tiny #2/0 blade through an inch of oak, you know exactly why these charts exist. You end up with a snapped blade, a scorched line of wood, and a lot of frustration. On the flip side, using a massive #12 blade on a delicate piece of 1/8-inch birch plywood is a recipe for a jagged, splintered mess. Finding that "Goldilocks" zone is what makes scrolling actually fun instead of a chore.
When you first get into scroll sawing, the numbering system for blades feels a bit backwards. You'd think a higher number always means "better" or "bigger" in a straightforward way, but it's more about the balance between the thickness of the metal and how many teeth are crammed onto each inch of the blade. Most of us start out just grabbing whatever came in the box with the saw, but once those break—and they will break—you're forced to actually look at a scroll saw blade sizes chart to restock your workshop.
Why the Numbers Matter So Much
The most common scroll saw blades use a numbering system that ranges from #2/0 (very small) up to #12 (very large). It's a bit like sandpaper grits; the numbers tell a story about how much material you're going to remove and how smooth the finish will be.
If you're looking at a scroll saw blade sizes chart, you'll notice that as the blade number goes up, the physical thickness and width of the blade increase, but the Teeth Per Inch (TPI) usually goes down. A #0 blade might have 20 or more teeth per inch, making it incredibly fine. A #9 blade might only have 8 or 9 teeth per inch.
Why does this matter? Well, it's all about chip clearance. If you're cutting thick wood, you need bigger gullets (the spaces between the teeth) to carry the sawdust out of the cut. If the sawdust stays in the "kerf" (the slit the blade makes), it creates friction. Friction creates heat. Heat burns your wood and ruins the temper of your blade.
Understanding the Standard Blade Sizes
Most hobbyists spend about 90% of their time using just three or four sizes. You don't necessarily need to own every single size on the scroll saw blade sizes chart, but having a variety helps.
The #2/0 and #0 Blades These are your "surgical" tools. If you're doing incredibly intricate fretwork—the kind where the wood looks like lace—these are your go-to options. They are very thin, which means you can turn on a dime. However, they are also fragile. You can't push these blades; you have to let them "walk" through the wood at their own pace. They're best for wood that is 1/8 inch thick or thinner.
The #2 and #3 Blades This is the sweet spot for most 1/4-inch projects. If you're making Christmas ornaments or small puzzles, a #3 blade is usually the "standard" recommendation you'll see on a scroll saw blade sizes chart. It's sturdy enough that it won't snap the second you put a little pressure on it, but it's still thin enough to handle tight curves.
The #5 and #7 Blades Once you move up to 1/2-inch or 3/4-inch material, you need some backbone. A #5 blade is arguably the most popular size in the world of scrolling. It's the workhorse. It handles medium-thick wood easily and lasts a decent amount of time before dulling. If you're cutting 3/4-inch pine or soft maple, a #7 will give you a bit more speed without leaving the edge looking like it was chewed by a beaver.
The #9 and #12 Blades These are for the heavy hitters. If you're cutting 1-inch thick hardwood or stacking multiple layers of wood to cut them all at once (stack cutting), you'll want these. They leave a rougher finish, so expect to do some sanding, but they won't wander or bend as easily as the thinner blades.
How to Read a Scroll Saw Blade Sizes Chart
When you look at a typical scroll saw blade sizes chart, it's usually organized into columns. You'll see the Blade Number, the Thickness, the Width, the TPI, and finally, the Recommended Wood Thickness.
Don't treat the "Recommended Wood Thickness" as a legal requirement. It's more of a suggestion. For example, if you're cutting a very soft wood like cedar, you can often get away with using a smaller blade than the chart suggests. If you're cutting something rock-hard like Ipe or Purpleheart, you'll probably need to move up a size on the scroll saw blade sizes chart just to keep the blade from overheating and snapping.
Another thing to keep an eye on is the type of tooth. A "skip tooth" blade has every other tooth missing to help clear out dust. A "reverse tooth" blade has the bottom few teeth pointing upward. This is a lifesaver because it prevents the bottom of your wood from splintering. Even if you pick the right size from the chart, picking the wrong tooth style can still mess up your project.
Choosing the Right Blade for the Job
I always tell people that if you're unsure, it's better to start a little larger. It's tempting to use a tiny blade because you want that ultra-thin cut line, but if the blade is too small for the wood thickness, it will "bow" inside the cut. This means your top line looks perfect, but the bottom of the cut is slanted because the blade flexed.
If you look at your scroll saw blade sizes chart and you're right on the line between two sizes—say, you're cutting 3/8-inch oak and you can't decide between a #3 and a #5—go with the #5. You'll have a much easier time keeping the cut vertical, and the slight increase in sanding time is worth the accuracy.
Also, think about the complexity of your pattern. If you have a 1/2-inch board but the pattern has a thousand tiny holes and sharp points, a #7 might be too wide to make those turns. In that case, you might have to use a #3 or #5 and just accept that you'll have to move very slowly to avoid burning.
Don't Forget About Blade Tension
Even if you follow the scroll saw blade sizes chart perfectly, your saw won't perform right if the tension is off. Thinner blades need more care. If you over-tension a #2/0, it'll snap like a guitar string. If you under-tension a #9, it'll flop around and give you a wavy cut.
A good rule of thumb is to pluck the blade like a string after you've tightened it. It should give you a high-pitched "ping" sound. If it sounds like a dull "thud," it's too loose. If it sounds like it's about to scream, it's probably too tight. As you get used to different sizes on the scroll saw blade sizes chart, you'll start to feel the "right" tension for each one.
Final Thoughts on Blade Selection
At the end of the day, a scroll saw blade sizes chart is a tool, not a rulebook. Every piece of wood is different. I've had pieces of cherry that cut like butter with a #3 and other pieces of cherry from a different tree that required a #5 just to get through without smoke.
It's always a smart move to keep a printed version of a scroll saw blade sizes chart taped to the side of your saw or on a nearby cabinet. It saves you from having to squint at the tiny writing on the blade packaging every time you need to make a change. Over time, you'll start to memorize your favorites, but having that chart handy is a great safety net for when you decide to try a new material or a different thickness.
Don't be afraid to experiment, either. If you find that a #5 works better for you on 1/4-inch ply than the #3 suggested by the chart, stick with what works for your saw and your hands. Happy scrolling!