Brett Wood Species that Require Carbide Tooling

Some wood species will destroy high-speed steel tooling. Here's a partial list. March 16, 2015

Regarding moulder knives has anybody out there compiled a comprehensive list of which species require carbide knives? I'm talking about species that you absolutely cannot run using high speed steel. It's sure an unpleasant surprise to grind HSS knives and have the wood in front of the moulder and everybody in position and then you burn the knives to heck with one ten foot board. (I can't remember if it was anigre or afromosia, that's why I need a list - bad memory). I didn't factor carbide knives into the cost when I quoted the moulder run. Some of you old timers and you tooling companies probably could suggest some species that you have run across that are "carbide" only. Sure would be handy to have a list to refer to. It would also keep us from buying carbide when it is really not needed.

I know you have to evaluate the length of the run, whether itís a one-time run, whether you have to hold tight tolerances from beginning to end of the run, etc. when evaluating carbide vs HSS. I'm more interested in hearing from others which woods can never be run with HSS.

Forum Responses
(Solid Wood Machining Forum)
From contributor U:
Well I can start the list for you: Mozambique, anigre, teak, rosewood and ebony. There are a few super coated steels out there that you might be able to get away with running a few hundred feet. The one we carry is called Endurance, you grind it the same way as high speed steel. There a few others brands that can do the same. I am sure others will be able to add to this list.

From the original questioner:
Thanks that's good info. How about garapa? I was told by a guy at East Teak that you absolutely have to have carbide but everybody else says HSS for a one time run or a coated steel like you suggested.

From Contributor C:
I killed an almost new set of HSS knives on four feet of ipe. "Only four feet, so why bother changing knives." Let me tell you why!

From Contributor M:
Ipe is bad for sure. Many exotics are, including wenge. I got the Byrd carbide head four years ago and am just rotating the cutters now. It's worth every penny.

From the original questioner:
Wenge is a good one, I had almost forgotten about that one. Well, we can add Garapa to the list. I tried using Leitz's Marathon tooling (M-3 HSS with some hard coating) on a 24000 Lft run of Garapa. Taking 1x6 deckboards into a 3/4 x 5-1/8" face T&G. We got 400 Lft through the moulder before the knives burned up. Wasted days and wasted nights is the song I'm singing right now. So I get to order $2000 worth of carbide tooling and be a few days late on delivery. I love the moulding business!