Ive always tried to aim for around 30 degrees.

 

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.

 

30 degress here

 

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.

 

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!!!

 

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

 

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. PR

 

I do wonder why some would go 60 degrees? Maybe brush hog blades. Thanks guys! PR

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.

 

I use a precision jig that is professionally manufactured and calibrated I can tell you that factory John deere blade's non-mulching ( when you set them on a known flat surface and the cutting edges are flat to the service) are at 40 deg to 41deg, this has largely to do with manufacturing, not all blades stamped have the same angles or trueness, although it is true that most blades are at or around 30deg, I also know that you CANT eyeball these angles. I have been sharpening and balancing blades for 30+ years, people gladly bring theirs to me and pay me to do it. the majority of my customers come back and tell me how much smoother their mower runs, that's due to proper balancing. And I don't mean the nail in the wall type, Thanks for having me.

 

Welcome to the board.

Just and FYI- this thread is almost 14 years old and many in it have moved on. Might want to check date stamps when posting to avoid dragging up old threads like this.

 

I change blades every two days. When I’m done with them you can cut paper with them. I like low angles then file the underside.

 

Welcome to the board.

Just and FYI- this thread is almost 14 years old and many in it have moved on. Might want to check date stamps when posting to avoid dragging up old threads like this.

Haha. Man. You're right.

 

So what is the point of being 14 years old ? It was very informative.

 

I just wanted to let the guy know that he dug up an old thread and probably didn't realize it being new here. This happens on here fairly often too.....a lot of guys do a search for something, see a thread on it someplace, and then join to post up about it without ever noticing the date stamp to see that they are dragging up very old threads when much newer threads also cover the same topics and include newer equipment.

 

I wish they would automatically lock after a month of inactivity. Or lock to members with less than 500 posts, or lock to all but the OP.

 

Pretty sure the best angle for blades hasn’t changed much in 14yrs. Lol.

 

as long as the discussion is still relevant than it is ok

 

new to sharpening my own blades. how do I get this angle? i have a bench grinder

 

Bench grinder I stand blades on their back and lean the blade into the wheel then move back and forth. I've ruined the workpiece rest doing this though.

 

Should be keeping a new unused blade on hand to compare its angle to your sharpened blade. There is a tendency to make them less of an angle over time.

 

Seriously? We should buy an extra blade so we can compare the angle? New blades are generally "cut" to the angle and not ground to the angle. Instead of spending money on a blade that is there just to compare with, why not make a jig for free and use it to get an even more accurate comparison of the blade angle?

 

The tendency to get a lesser angle over time is what happens when you sharpen them without a jig by hand. Using something as simple as what I posted with the bench grinder will give you a much more consistent and accurate angle and pretty much the same every time you sharpen them. If you want technical, you should readjust the angle as the grinder wheel wears down. Smaller wheel=different angle.

 

Most of us have new blades on hand to rotate into the cycle, so saying that you should use one as a go by doesn't seem out of line to a reasonable person, especially when you use it to compare how far off your angle is becoming over time from repeated sharpenings (most on here don't use a jig or fancy grinder, but use what they have-files, bench grinder or flap sander/angle grinder).

The biggest reason the angle changes over time is due to wear and guys trying to get the edge sharp without stopping to consider the entire angled face needs to be done at the same time, which takes more time to do.

Some may find this video interesting. Oregon blade manufacturing-

 

Refer back to my bench grinder post. It didn't cost anything to make it so I would have the right angle every time I use it. I don't spend my money on new blades to sit around. I have 3 sets of blades I rotate on my mower. I don't have to have new blades that I won't put to use for a good season or more. Most "reasonable" people don't waste their money on something just to have it sit on a shelf. What happens when you "rotate" the new set of blades into the bunch? Wait, I think I know the answer, you blow money on a new set just so they can sit and look pretty on the shelf?

 

use the Mag 8000. Very easy to maintain consistent proper angle throughout life of blade.

 

One thing about it everyone has their own way and strong opinions on blade maintenance.

In high school I tried using the milling machine to cut a new and precise angle on blades. Either the cutter head wasn't sharp or something because it wouldn't cut the blade steel at all.

 

If you cutting grass for living probably good idea invest in dedicated sharpener. Have had Mag8000 15 plus years. Sharpened probably well over thousand blades. 2 min perfect angle every time effortless.

 

i have this one and like it

https://www.allamericansharpener.com/5000