Carbide Jointer knives

[Rhythm House Drums]

I rarely use softer woods with what I do. A lot of hard maple, padauk, purple heart... It seems as though my jointer blades dull quicker than they should... maybe cause of the hardwoods. Would I benefit from using Carbide tipped knives? Anyone have experience with these? I have a 6" jet jointer... JJ6CS I think. I think the knives are 6.125 long. I've replaced them with other jet blades from woodcraft maybe twice now in the past 2 years. I don't run a lot of wood through, but the wood I do run is usually hard.

Other than advice about the carbide knives, any advice on where to purchase? I have 2 sets of the high speed steel knifes, and I'm wondering if I should invest in some carbide or just get these sharpened.

Thanks guys!

 

[Bill Clemmons]

I don't have carbide knives, but I would assume they would outlast HSS knives. Whether they are worth the extra cost is another matter.

As for buying knives, the last few sets of planer or jointer knives I bought came from Amazon.com. Good price, free shipping, etc. They were Freud.

Bill

 

[gator]

May be a silly question, but why would you replace the knives with new instead of having them resharpened? If you saved the old knives, you now have three sets. You could have two sharpened and then send in each set as it dulls and always have two sharp sets on hand. FWIW, I use Raleigh Saw to resharpen my saw blades, jointer and planer knives.

George

 

[Rhythm House Drums]

May be a silly question, but why would you replace the knives with new instead of having them resharpened? If you saved the old knives, you now have three sets. You could have two sharpened and then send in each set as it dulls and always have two sharp sets on hand. FWIW, I use Raleigh Saw to resharpen my saw blades, jointer and planer knives.

George

I actually got the jointer used for about 350 with 2 sets of knives and a mobile base... I lucked out, but I haven't actually bought new knives yet. My question is more along the lines of the pros and cons of a carbide knife. Wondering if people love them and think it makes their tool cut better.. or if people think they're not worth the extra price. It's time to change knives.. and I wanted some input if I should "upgrade" to carbide knives or just resharpen. Anyone with experience using carbide in their jointers?

 

[bob vaughan]

Some of the questions and comments here ASSUME all high speed steel knives are the same. That's true in that maybe the steel formulas used qualifies as high speed steel, but there's a stark difference in hardness and durability. I tried a set of cheapie china-made knives once. I got 200 linear feet of jointing before they were totally trashed. I was doing a hard maple job where I could monitor things. I removed the knives, tossed them in the trash and went back to Amana brand that my local sharpening service sells.

I've also tried carbide. Carbide is dull to begin with compared to sharp HSS. Carbide takes a whole lot more feed pressure and horsepower to cut satisfactorily. Won't do that again either.

 

[TBradley190]

I can't speak for jointer knives, but I have carbide knives on my 15" planer and I'm about at 1000 b/f and that's red oak, walnut, cherry, and tobacco barn pine. I just planed some cypress this morning and it looked great. They have lasted me 4x as long as HSS. JMO

Tim

 

[jimwill48]

I would think that the carbide knives would prone to chipping. I use a lot of carbide inserts when I do metalworking and it doesn't take much to chip them. I have used carbide inserts in a indexable end mill to do some wood milling on the milling machine (milling pockets) and knots can chip the insert faster than metal or so it seems.....james

 

[mlzettl]

Kevin,

If I were you, I would consider replacing the whole cutterhead with a carbide insert spiral cutterhead. Not only will you get much better durability of the cutting edges, but you will also benefit from a cleaner cut with almost no tear out whatsoever. I also work almost exclusively with hardwoods, including some very dense and abrasive varieties like jatoba, bubinga, wenge, etc. I have a spiral cutter head in my 20" planer, and HSS steel knives in my 8" jointer. I am about to purchase a new jointer, and there is no question that I will have a spiral cutterhead in it. I will admit that this would be a pricey alternative for you, and you may not find the value in it.

With all that being said, if you have two sets of HSS knives for your jointer, just send one out for sharpening as soon as you replace them, and you will always have a sharp set on hand. I bought mine from Holbren, and have been very happy with both the price and edge retention. The other problem, at least for me, is just the hassle of changing and setting the HSS knives. Even with a Magnaset gauge, it still takes a lot of time and fussing. With the inserts, if you chip one, you just have to rotate it 90 degrees and you are back in business.

Of course, these are just my opinions, and others have their reasons for preferring HSS standard cutter heads. Hope this helps.

Matt