Chrome, Cobalt, HSS tersa knives

[Jack Camillo]

The Minimax jointer-planer combos are shipped with chrome tersa knives, the least expensive to replace. They also sell cobalt and high speed steel, in that order of cost. Can anyone comment on the difference in blade durability and finish they produce? (the Hammer apparently uses the cobalt)
I'm trying to justify the Minimax over the Hammer. I like the added power, the magnetic switch, and the fence design. They want extra $ for the euro-style guard, however, which I THINK I would like...
Comments? Thanks,
jack

[Gary Keedwell]

The Minimax jointer-planer combos are shipped with chrome tersa knives, the least expensive to replace. They also sell cobalt and high speed steel, in that order of cost. Can anyone comment on the difference in blade durability and finish they produce? (the Hammer apparently uses the cobalt)
I'm trying to justify the Minimax over the Hammer. I like the added power, the magnetic switch, and the fence design. They want extra $ for the euro-style guard, however, which I THINK I would like...
Comments? Thanks,
jack
What is the price difference between HHS and Cobalt? I would definetly think cobalt would hold up better. We used to buy cobalt drills for somrthing like 15% more then HSS but the cobalt would more then cover the extra price...sometimes lasting 150-200% Xtimes as long.
Gary

[Chris Padilla]

Jack,

Play your cards right and I'm sure you can get the folks at MM to toss some more freebie knives for you. Every time I ordred something from them, I always ask them to toss in a set of knives for my J/P (Have the FS41-Elite, 16").

The short story: HSS can be ground to a finer edge than cobalt but it will wear faster than the cobalt.

[Gary Keedwell]

Jack,

Play your cards right and I'm sure you can get the folks at MM to toss some more freebie knives for you. Every time I ordred something from them, I always ask them to toss in a set of knives for my J/P (Have the FS41-Elite, 16").

The short story: HSS can be ground to a finer edge than cobalt but it will wear faster than the cobalt.
I know that you can get a sharper edge on HSS than carbide. As for cobalt ...I'm not sure about that. Actually cobalt is HSS with about 5% cobalt mixed into it. Either way your going to get a better edge then carbide. Carbide starts a little duller but lasts up to 10 times longer. Carbide and cobalt are brittle and they both could break or shatter .
Gary

[Eddie Darby]

Ask for one of each, and then see how well they perform.
Since they are easy to change quickly, I would try various blades with different woods, so softwood would get one blade, and a run of tough exotic hardwood might get another blade.

[Jamie Buxton]

High speed steel is not a single steel, but rather a whole family of steels. Some of them contain metals like chrome or cobalt or tungsten. When a vendor offers "HSS or cobalt steel", he's not being at all clear what he's offering. That's like offering you meat or beef. Here's a link to some basics about HSS: http://en.wikipedia.org/wiki/High_speed_steel

[Jack Camillo]

Thanks for the replies so far. Interesting that no one has commented on "chrome" knives. I've never heard of chrome jointer/planer knives...

[Jamie Buxton]

Thanks for the replies so far. Interesting that no one has commented on "chrome" knives. I've never heard of chrome jointer/planer knives...

"Chrome" knives are probably made from a high-speed steel which has chrome in it. Read that link I posted above.

[Gary Keedwell]

If I remember right, chrome is one ingredient that makes stainless steel.
Gary

[Joe Mioux]

. They want extra $ for the euro-style guard, however, which I THINK I would like...
Comments? Thanks,
jack

Im not going to bother with the knife issue.

If you go with the "American" guard you will probably crack it on your first or second time when changing the combo from a J to P.

I keep forgetting to move the guard out of the way until the jointer wing hits it and cracks it just a bit more. For me, I would be surprised if the guard lasts a year.

joe

[tim rowledge]

Amazon list the 300mm HS blades at $27.50 each, the M42 at 30.40 each. MM USA list them a tad higher and also has the chrome ones at $15 each. Laguna lists the M42 at $32.25 and the carbide at $125......

[Rye Crane]

Hi Jack,

I am waiting for my new minimax jointer planer to arrive, hopefully in a month. I was also told it would arrive with the tersa head fitted with chrome knives. Yes, these are the cheapies, but there is a solution near you. Call or email Ed Papa at Simantech Inc. 516-887-5888 or email at simantec@optionline.net their website is found under simantech.com goggle it and they have sets of knives in chrome, HSS, & Cobalt.

Their pricing is very good. They also sell Martin woodworking machines and are the outlet for Aigner safety equipment.

I also found a source locally for me that stocks tersa knives and their clones (less expensive) It's Bay Area Carbide, Concord, Ca. 925-687 7543 The boss there is Doug McAdoo and he gives discounts for orders at certain break points. So if you wanted two sets of knives I think you would get 5 or 10% off his prices and they are just a bit lower than Simantec. Bay Area Carbide does my sharpening and are a great resource, everytime I stop in or call Doug I get a little more of an education in this stuff.

I would check out these resources and compare your pricing with MiniMax and get set up with one HSS and one Cobalt set to see which one works best for your application. The Carbide knives are very pricey but I understand you can run two Carbide knives and two HSS on the same tersa head and you will get an average longer life for the set. I would have to think that the HSS will just wear down to the Carbide and coast along for the ride, letting the Carbide do all the work, but they should last along time.

Let us know what you come up with.

Rye Crane

[Dan Forman]

Best source I found was here: http://www.simantechinc.com/index.php?action=category&id=2

For comparison, 300mm Cobalt are $22.22 ea. Last time I looked for 350mm, they were about $25 each.

The cobalt blades have a slightly different grind, which is supposed to improve performance over the regular HSS blades in harder, more difficult woods. The Chrome blades wear faster than either, and are only recommended for softwoods.

I found that while the Tersa blades are easy to change, they tend to chip easily. If there were any knots in a board, there would often be tell tale raised lines in the board directly after the knot showing where the blades had chipped.

I eventually got a Byrd Shelix head for my Mini-Max FS35, partly due to the chipping issue, and partly just because I really like gnarly woods that tend to tear out when jointing or planing.

Dan

[Jim Becker]

I was actually surprised at how long the chrome knives lasted on my MM J/P. It took a long time for me to go through the two sets that came with my machine! That said, when I bought more knives the end of last year when MM had a buy-one-get-one sale, I bought the HHS knives and am happy with them. They actually don't give quite as "fine" a finish as the sharp chrome knives (when new), but they do a great job. I tend to run stock through at a shear angle, too, which always improves the finish.

[Jack Camillo]

Well, I went with the MM 12in j/p, and asked for a set of cobalt knives. Should have the machine in a week or less, and will of course post some pics - probably of me and my wife dragging it across the grass on a plywood sled towards the correct door, and punching holes in the walls to get 'er in the shop, embedded deeply into my finished basement... Thanks for all the replies on the knives, and tip to the other smc thread - I love pictures. I'll be calling you guys (on smc) if I have any set-up problems.
jack

[Jim Becker]

Congratulations, Jack. Nice machine...you're going to enjoy having it in your shop!

[Joe Mioux]

Well, I went with the MM 12in j/p, and asked for a set of cobalt knives. Should have the machine in a week or less, and will of course post some pics - probably of me and my wife dragging it across the grass on a plywood sled towards the correct door, and punching holes in the walls to get 'er in the shop, embedded deeply into my finished basement... Thanks for all the replies on the knives, and tip to the other smc thread - I love pictures. I'll be calling you guys (on smc) if I have any set-up problems.
jack

I don't envy trying to get an MM fs30 down in a basement.

As far as set up goes. unbox, de-pallet it, wire it up and turn it on.

[Steven Wilson]

I use the HSS ones in my CU350 (14" j/p) and really like them. I have a couple of sets of chrome ones in various states of sharpness and I use the sharper set for pine and other soft woods and the duller set for rough work. With the Tersa head it's great to use a junk set of knives to do the rough work and then switch to a good set for final thicknessing.