Export thread

How Sharp Should Blades Be?

#1

P

panabiker

I just bought a pair of new blades made by Arnold. I noticed that the edges are painted and are not that sharp but very straight. I now wonder if I have been sharpening too much unnecessarily. Another point of reference is that the nylon strings used in the trimmers are even duller and yet the areas I trimmed don't seem to suffer tearing or other illness associated with bad blades. Any thoughts?


#2

Carscw

Carscw

panabiker said:
I just bought a pair of new blades made by Arnold. I noticed that the edges are painted and are not that sharp but very straight. I now wonder if I have been sharpening too much unnecessarily. Another point of reference is that the nylon strings used in the trimmers are even duller and yet the areas I trimmed don't seem to suffer tearing or other illness associated with bad blades. Any thoughts?
Click to expand...

First stop wasting money on Arnold blades. They just don't last long.
You do not want to sharping blades to a razor edge. They will just dull fast and you will go threw more blades.
A new blade is as sharp as it needs to be and the pitch is what has been found to be the best for cutting grass and max life of the blade.

Most trimmer line is really not any wider than the edge of a blade.
The speed if the line is faster than most blade tip speeds


#3

P

possum

I noticed the same thing. The blades on the new MTD mowers are very sharp so that new mower really cuts nice. But the replacement blades are pretty dull. I suppose product liability has something to do with it. The blades are the same as far as I can tell. Just sharpen them some more if you wish or use as is if they suit your needs. I like the Arnold blades.


#4

R

Rivets

A good sharp blade cuts faster and leaves the lawn looking better than a dull blade. All blades leaving our shop are sharpened to the point that they will cut you if you're not careful. New blades are not to that point for safe handling and $$$$. On the average lawn a sharp blade will last a season for a homeowner.


#5

okiepc

okiepc

I sharpen my blades 3-4 times a season, I sharpen it as sharp as I possibly can & you can tell the difference when you start mowing, just a clean cut. The blade never gets really dull, but I like sharp better. :thumbsup:


#6

Fish

Fish

I have noticed that a lot of the brand new blades are very sharp, but are end dipped in thick paint for safer/easier shipping, which chips off quickly
when mowing.


#7

Carscw

Carscw

For a homeowner that can take the time to sharping blades after every few cuts then make them razor sharp. The thing is when you give them a razor edge they dull and chip faster and they don't last as long.

For some of us cutting 20 yards a day we do not have time to change blades 4 times a day the factory puts a edge on the blade that has been found by many study's to give the best cut and longest life of the blade.
You say putting a razor edge gives a better cut. Ok maybe for one cut then the edge is gone. A high lift blade sucks sand up do you not think that dulls the blades.

And yes they do dip them in a rubber paint for shipping. For safety and so they don't rust.


#8

T

tybilly

carscw..how many times do you rotate blades (from new to junk)...and I was told that razor sharp caused a grass fungus...not sure how true that is.


#9

lawn mower fanatic

lawn mower fanatic

tybilly said:
carscw..how many times do you rotate blades (from new to junk)...and I was told that razor sharp caused a grass fungus...not sure how true that is.
Click to expand...

I know dull blades can. :eek:


#10

Carscw

Carscw

tybilly said:
carscw..how many times do you rotate blades (from new to junk)...and I was told that razor sharp caused a grass fungus...not sure how true that is.
Click to expand...

The thing is that a razor sharp blade only stays razor sharp until it cuts grass then you end up with a flat edge. The factory edge and pitch has been found after many study's to be the best for the grass and longer life of the blade.

A good good blade will last me about a month. Around 300 grass cuts. I use them till the fins get to thin.
If I was to sharping my blades razor sharp I would get maybe 50 cuts out of them.
A pine cone will chip a razors edge.


#11

H

Hustling

Carscw said:
The thing is that a razor sharp blade only stays razor sharp until it cuts grass then you end up with a flat edge. The factory edge and pitch has been found after many study's to be the best for the grass and longer life of the blade.

A good good blade will last me about a month. Around 300 grass cuts. I use them till the fins get to thin.
If I was to sharping my blades razor sharp I would get maybe 50 cuts out of them.
A pine cone will chip a razors edge.
Click to expand...

I agree with Carscw on this one... maintaining the angle is very important but razor sharp will only leave your blades chipped or folded over easier. You want it to be about like a butter knife - you can run your thumb along it but it won't really cut you - it will cut grass just fine though. You will get a better cut for longer. I had an old timer who owned a mower repair shop teach me how to sharpen blades. You also don't want to get the blade too hot when sharpening them. Use light pressure and go back and forth several passes as not to get it too hot. If you get it too hot you will weaken the steel. Maintain the angle - very important.

How often you sharpen depends on - how many rocks etc. you have hit, how much grass you cut. I typically sharpen after about 40hrs. of mowing and blades are never too bad. Check your blades regularly - while your cleaning out the deck.


#12

Carscw

Carscw

Hustling said:
I agree with Carscw on this one... maintaining the angle is very important but razor sharp will only leave your blades chipped or folded over easier. You want it to be about like a butter knife - you can run your thumb along it but it won't really cut you - it will cut grass just fine though. You will get a better cut for longer. I had an old timer who owned a mower repair shop teach me how to sharpen blades. You also don't want to get the blade too hot when sharpening them. Use light pressure and go back and forth several passes as not to get it too hot. If you get it too hot you will weaken the steel. Maintain the angle - very important. How often you sharpen depends on - how many rocks etc. you have hit, how much grass you cut. I typically sharpen after about 40hrs. of mowing and blades are never too bad. Check your blades regularly - while your cleaning out the deck.
Click to expand...

^^^^^^ agree 100%


#13

M

motoman

Since I only have one rider with blades of .200" thick I have not sharpened the thinner ones, but have seen them on display at wal mart. They can't sell them because they are over priced IMO, but there they sit with special red tags , year after year. Anyway most are much thinner than .200," making sharpening easier and quicker, but more prone to over heating on a grinder. The thin ones look like they are made for easier (?file) sharpening. Such thin blades probably survive machine sharpening only with the expensive , softer grinding wheels, called pink and white wheels by the pros. Meanwhile, the lowly grey H Frt $8 wheel keeps on grinding good edges for me. :2cents:


Footer Links 1

Top