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Tersa™ Knives FAQ

What Is the Tersa™ Planer Knives System?

The Tersa™ system has been patented in 1984 in Switzerland. The system consists of the Tersa™ cutter head and the Tersa™ Planer Knives.

The Tersa™ system is revolutionary as it drastically reduces the amount of time it takes to change blades. Whereas traditional planer blades can often take hours to change, set and sharpen, Tersa™ blades can be changed in a matter of minutes, due to their unique wedge locking system. To see for yourself just how fast a Tersa™ knife change is, please click here.

Can I Use Tersa™ in My Planer or Jointer?

Yes, most machines can be retrofitted with a Tersa head of the same dimensions of your current head. You just need to swap out the head in your machine. The only time a machine can't use Tersa blades is if there is no side access to the head to slide knives in. However, on most machines a small hole can be machined in the casing to allow this.

Contact us for a quote, or use our online head quote tool if you know your head dimensions.

Is the Tersa™ Planer Knives System Quieter Than Regular Planer Systems?

Yes, according to sound tests the Tersa system is significantly quieter than traditional straight blade heads. It is comparable in noise level to a helical cutter head.

How Do I Change Tersa™ Planer Knives?

Tersa blades are held in by wedges behind the blades. Tap them down with a piece of wood or a Polykey, and slide the knives out sideways. You can flip them to their other side if it hasn't been used, or replace them with fresh blades.

To see a video demonstrating a Tersa™ Knife change please click here.

How Long Do the Tersa™ Knives Take to Change?

You can change Tersa™ Knives within 1 to 2 minutes.

Do I Need to Change Screws or Adjust Tersa™ Knives?

The Tersa™ systems brilliant design leaves no screws to deal with. A consistent indexed height of Tersa Knives eliminates the need for adjustment. For more on changing blades please see the tutorial on our video page here.

Which Tersa™ Knife Type Should I Use?

The HSS knife has an angle of 40°, ideal for soft woods such as cedar, pine, fir, etc. The M+ Tersa™ planer knife has an angle of 55° which makes it more durable, used on hardwood like maple, birch, oak and cherry wood.

Carbide knives are very hard and durable on hard and soft woods. They are also more brittle, so be careful to use them only on clean wood free of staples, rocks and dirt.

Chrome knives are our least expensive knife and can only be used on soft woods. They can be useful to clean up dirty wood as well before putting in more expensive knives.

To see which material to use for which woods, see our recommended list here.

Can I Sharpen Tersa™ Knives?

Tersa™ Planer Knives don’t need to be sharpened, the blades are two sided and can be recycled after use.

Are Tersa™ Knives Sold Individually or in Sets?

Tersa Knives are sold and priced individually. We package them in pairs in cardboard sleeving, and put a label identifying packages with only one knife in them. Any amount of knives can be ordered including odd numbers.

What Lengths of Tersa™ Knives Are Available?

Tersa™ Planer Knives are cut to order, thus they are available in any and all lengths. No need to use a long, more expensive planer knife on a job that could be done with a shorter knife size, thanks to the easy Tersa™ changing system.

How Do I Know I'm Getting the Real Tersa™ Planer Knives and Not an Imitation?

There are many inferior imitations available on the market.

Original Tersa™ Planer Knives have the name etched on the blade, as well as HSS, M+, MD (carbide) or CR (Chrome Steel) depending on the knife type, and are packaged in a distinctive cardboard sleeve.