Carbide Tipped Knives

[Vince Ryce]

I need to buy new planer knives. Do Carbide Tipped really last up to ten times longer.

[Dave Sweeney]

Interesting how an ad for Carbide Tip Planer Blades just happens to be right under this post.

[Gene Howe]

programmers for these ads are pretty sneaky, huh?

[Vince Ryce]

I am sorry to say, but I have nothing to do with the add following my post.
I have another question related to this.
I just bought an older Rockwell. The head rotates at 3450 RPM which by today standard is pretty slow..
Wouldn't the linear speed be too low for carbide.

[Brad Townsend]

I put carbide tipped knives on my jointer a couple of years ago. Haven't done anything with them since. They have worked fine for me. Can't really say whether they would last TEN TIMES longer. As woodshops go, mine have had pretty light use, as I'm running the jointer infrequently. However I know I would have resharpened HSS knives several times in the same length of time.

They can get pretty expensive. The best price I found was Global Tooling. I think I paid around $130 for four 8" knives. Some places will charge closer to $200. For that kind of money you might as well pay a little more and order a Byrd head.

[Van Huskey]

I have not used carbide tipped jointer/planer knives but with other tooling (router bits, circ saw blades bandsaw blades etc) they usually last longer than 10 times.

I do think the best long term cost savings is with a carbide insert helical head, though the initial cost is high but also absolves one of the knife setting PITA.

[Peter Quinn]

Yes they last ten times longer easily in most wood species. But brazed carbide tipped do not give as good a surface quality IMO as sharp HSS, and solid carbide is VERY expensive. And they chip just as easily if you hit sand, rocks or an errant staple, but cost several times more to have reground typically, so there is that to consider. Keep your lumber clean and off the ground and they can prove to be a real winner. Push rough sandy lumber yard fork truck muck into them, and it can prove to be a pricey luxury with little payback.

[Vince Ryce]

Thank you all for your replies.
I would probably go for a Shelix head, but for my 18" planer it is too much money.
I am now considering the DISPOZ-A-BLADE system.
Have some of you experienced it.
Thanks again for the help.

[Tom Walz]

I'll second Peter Quinn on all he said.

You can get 10, 50, maybe 100 times the life with carbide depending on the type of carbide.

When we test edge sharpness we use edge radius as a measurement. With carbide you are generally doing well to get an edge radius of 10 microns. With an advanced cermet (like tungsten carbide but with titanium instead of tungsten, sort of) material you can get an edge radius of 3 to 4 microns. With steel you can hone the edge down much finer than that.

[Rod Sheridan]

My smart answer is that it depends when on the timeline you hit that pebble in the wood, whether they last 10 times as long as HSS knives.

The other answers you received regarding surface finish, lifespan costs are something only you can answer.

I have a disposable blade planer/jointer and find that the cobalt blades have very good lifespan and produce a superb surface finish.

Regards, Rod.