What happens when you change your planer blade angle?

[Scott Huff]

It's time to resharpen my Dewalt planer blades and I want to try a different angle to lessen tearout. The manual specifies 42 degrees. What happens if I go to 35 degrees? What if I go to 45 degrees or so?

[John Christiansen]

It's time to resharpen my Dewalt planer blades and I want to try a different angle to lessen tearout. The manual specifies 42 degrees. What happens if I go to 35 degrees? What if I go to 45 degrees or so?

The jig I made to resharpen my planer blades resets the angle to 45 degrees. I can't say that I have noticed any difference, between resharpened ones and new. But either one, 45 or 42, cut with a lot less tearout than dull ones.

[Todd Burch]

I'm not an expert on this matter, but I can tell you where to find out. Check with a sharpening service in your area and get their opinion. Different angles are typically specified for use with different woods (hardwoods vs. softwoods). 42° is probably a good compromise. The DeWalt tech line should be able to give you their theory on the matter too.

You might could call Rob Lee up @ Lee Valley - his dad wrote the book you know!

[Paul Kunkel]

When I resharpen with my Makita wet wheel, I put a slight microbevel on my blades. It serves 2 purposes: 1 gets the small nicks out quicker & 2, seems to make the cuts cleaner-ie:less tearout. This is just a personal observation and has no real backing. I don't know what the angles are, I just work with what I start with.

[Tom Hintz]

I tend to stay with the steeper angles on my knives, like 35 rather than 40-degrees just because generally speaking the lower angles dull faster and are more susceptible to damage because the cutting edge is thinner.
As long as the blades are sharp I see no difference between the angles when jointing or planning. I also try to stay close th what the manufacturer had on the blades to start with, just the steeper end of the tollerance range if they provide one.

[Scott Whiting]

I only have riser blocks on my grinder for 40°. Thats what all my customers get. Very few people do all of the same type of wood with the same moisture content to try and match the knife angle to the usage.