How do I know when a blade is dull?

  • Advertise with us

« back to Scrollsawing forum

Forum topic by WoodNSawdust posted 10-31-2015 08:24 PM 2314 views 0 times favorited 6 replies Add to Favorites Watch
View WoodNSawdust's profile


1417 posts in 1685 days

10-31-2015 08:24 PM

Topic tags/keywords: scroll saw blade dull blade

I am a beginner at scrolling. I release the easy answer to my question is “when the blade stops cutting”, but how does a beginner know?

-- "I love it when a plan comes together" John "Hannibal" Smith

6 replies so far

View MrUnix's profile


7478 posts in 2708 days

#1 posted 10-31-2015 08:31 PM

It will keep cutting, even when dull, so that don’t work :)

When the blade gets dull, you will get increased resistance to cutting. The blade will start to deflect more from you pushing harder to make the cut, making it more difficult to follow the line or guide the cut in the right direction. Eventually, it will be come bad enough that you wind up breaking the blade. When it starts getting hard to control the cut, it’s time to change the blade.


-- Brad in FL - In Dog I trust... everything else is questionable

View sawdust703's profile


270 posts in 1929 days

#2 posted 10-31-2015 08:45 PM

You’ll notice some burning of the wood, depending on the type of wood, you’ll have issues following the cut line, & you’ll keep putting more pressure on your work piece into the blade, trying to get it to cut.

-- Sawdust703

View hhhopks's profile


659 posts in 2886 days

#3 posted 10-31-2015 09:10 PM

As stated above.
In addition, the blade with get hot.
There will be resin built up along the tooth.

If you are referring to a hand saw, it would be more obvious that you are building sweat and not making a whole not of progress.

-- I'll be a woodworker when I grow up. HHHOPKS

View CharleyL's profile


223 posts in 3873 days

#4 posted 10-31-2015 09:34 PM

I’ve been scroll sawing for about 25 years and have come to the conclusion that there is no perfectly accurate way to tell how dull they are without a microscope, but here are a few tips. A blade that’s dull will burn the wood, however running the saw too fast will do this also. So my real answer is, if you have been cutting for a while and the blade hasn’t been burning the wood at this speed setting, but it is now, the blade is likely dull. But if you notice that the blade isn’t cutting through the wood as fast as it has been, the blade is also likely dull. If you are cutting many of the same pieces over and over you will also be able to easily tell by looking at the cut quality after cutting each piece because you will know what a sharp blade cut on that kind of wood is supposed to look like. The blade also becomes harder to steer and follow the line because you are pushing too much. The edges of the cut usually get more fuzzies when the blade gets dull too.

I’ve been making the same little Christmas gifts every year for 5 years, this is year 6. Last year I gave away 91 of these. This year my goal was to have 150 ready by Thanksgiving, but I had surgery in August and my doctor told me to sit still for a week, so I sat at my scroll saw all day, every day for a week and cranked these little gifts out. So early in September I reached my goal of 150, but I’m still making them. #268 was made last Thursday and I may still continue making them in my spare time until Thanksgiving. If any are left (I doubt it), I will just save them for next year.

I give these out to every woman, waitress, cashier, store clerk, nurse, etc. who helps me in some way during the Christmas Season. Most men don’t appreciate them, so I don’t usually offer them to men, unless I know them to be woodworkers. When giving them out I hold out my hand to them, palm down, with one of these in it and then I say “Merry Christmas”. When they reach out toward me I drop it in their hand. It brightens the spirit of every woman who receives one of these from me and it puts me more into the “giving spirit of Christmas”. I’ve always loved Christmas and have been putting out decorations with over 7,000 lights each year too. There are also 2 decorated trees in the house and a candle light in every window. Yeah, I guess I’m a little crazy, but I have always loved Christmas.

I’ve gotten so good at making these little gifts, that it now takes me less than 10 minutes to make each one.
Using a #1 R Flying Dutchman blade I can get about 30 of these cut out of pine before I need to replace the blade because it’s “too dull”, and I rarely break one of these blades. With the same size blade from another popular scroll saw blade company, cutting the same little Christmas gifts on the same saw, I get 15-18 pieces cut before the blade gets too dull or breaks. Since the Flying Dutchman blades are only a few cents each more in quantity it seems crazy to buy any others. I have no financial or other interest in Flying Dutchman, but I love their scroll saw blades and use a lot of them.


View tomsteve's profile


964 posts in 1728 days

#5 posted 11-01-2015 01:15 PM

charley and the others have great info.
you will learn as ya progress.
different wood species will dull a blade at different rates,too.

View sawdust703's profile


270 posts in 1929 days

#6 posted 11-01-2015 04:19 PM

Tom is right on the point about different woods. Some hardwoods are susceptible to burning when you turn corners, curves, etc. This is where blade size & speed comes to light. And the more you scroll, the more you’ll learn. Don’t be afraid to try all sizes & types of blades. Every blade size has its place & use, & you can learn to use different sizes for more than just one purpose. As Charley pointed out, there are several ways to tell when your blade is dull. Experience is the best teacher. Try several different types of wood. Different patterns, etc. Scrolling takes time & patience to learn, but will also teach you patience, focus, & many other woodworking skills. Scroll in several different thicknesses of wood to see what you like to work with best. Once you figure that out, try to stay within that realm. Your skills will build around that, then you can use other thicknesses as the project requires it. My preference is 1/2”. I do most everything in that thickness, or there abouts. Most beginners get the idea they need to start with 1/8” or 1/4” material. Unless you’re going to spend your scrolling career making puzzles, ornaments, & such, you’re wasting your time. Put a #3 or #5 polar blade in your saw, draw ya some lines on a piece of 3/4” thick pine, oak, whatever you have available, & start making sawdust, brother!! We’re here to help you up the trail as you go, when ya need assistance. Enjoy your venture!! Be safe!

-- Sawdust703

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics