Angle of Mower Blades

Discussion in 'Lawn Mowing' started by PR Fect, Jan 2, 2006.

  1. PR Fect

    PR Fect LawnSite Bronze Member
    Messages: 1,076

    What angle do you use on your blades. I have seen 30,35,45, and 60 degrees all mentioned on this site. Whats the best and why?
  2. MJLsLawnCareNmoreLLC

    MJLsLawnCareNmoreLLC LawnSite Senior Member
    Messages: 840

    Ive always tried to aim for around 30 degrees.
  3. Pecker

    Pecker LawnSite Bronze Member
    Messages: 1,454

    Generally, the finer the cutting preferred, the lower the angle - speaking of kitchen cutlery for example, which cuts tender meats and vegetables. Conversely, you would need a higher angle for a hunting knife such as one used to cut off catfish heads so that the blade does not get nicked so easily. I don't recall specific angle degrees (although a chef's knife would be around 20 degrees if I remember correclty), but you get the idea. On mower blades, think of what they will be cutting through - thats what helps me get a good angle and my blades which usually hold a nice edge for 10 - 15 hours cutting mostly St. Augustine and lots of pine cones. If I were to guess at the cutting angle I use, I'd say somewhere between 30 - 40 degrees - but only a guess. Hope it helps.

    JKOOPERS LawnSite Bronze Member
    Messages: 1,259

    30 degress here
  5. Roger

    Roger LawnSite Fanatic
    Messages: 5,951

    I can't find it now, but I think the Exmark site (on LS's forum) had a recommendation for 37 degrees. However, the angle might depend upon the kind of blade -- it should depend upon the kind of blade. I only use high-lift, so that was the only angle measurement that had any meaning to me.
  6. CutInEdge Lawn Care

    CutInEdge Lawn Care LawnSite Senior Member
    Messages: 677

    30 degrees here. We use a RPG-21 blade grinder and a precision ball bearing balancer. We always wear the paint off first, you'll understand the first time you sharpen when paint is still on. Good Luck!!!
  7. PR Fect

    PR Fect LawnSite Bronze Member
    Messages: 1,076

    Thanks, I want to build a jig for my bench grinder. We have 3 types of mowers, that use 3 types of blades. ( mulch, gator, high lift ) I was hoping for a happy medium, so as to not have to readjusts my jig. 30-35 sounds like the way to go. I do wonder why some would go 60 degrees? Maybe brush hog blades. Thanks guys! PR
  8. PR Fect

    PR Fect LawnSite Bronze Member
    Messages: 1,076

    I dug around in my carpenters box an found a tool that measures angles. I put it on a few blades we have. Most are at 3O that are new. I was surprised that the ones that I have sharpened before were any where from 23 degrees to 40. I guess doing it by eye is not the way to go.:confused: PR
  9. MJLsLawnCareNmoreLLC

    MJLsLawnCareNmoreLLC LawnSite Senior Member
    Messages: 840

    Sort of. I would say that anyone sharpening their blades at 60 degrees isnt aware of it, or they are doing it for a reason. 60 degrees would help prevent knicking the blade when cutting thicker stuff or rough yards. A blade at 30 degrees is good for cutting soft things like grass in a well maintained lawn. If you were to cut grass with blades at 60 degress you would more likely tear that grass not cut it, which would open up a whole new can of worms.:nono:

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