Tools, Sharpening and Power Machinery - How sharp is good enough for mower blade?

I am a reasonably good sharpener of knives and I use the test of whether I can shave the hair off the back of my hand to decide when the edge is honed. What is a good way to determine when the mower blade is ready for use? Should it be as sharp as a knife?

Judging by the blades on my mower they don't need to be sharp at all. I think my blades just beat the grass into submission.

I think if you can hold the blade at arms length and it looks sharp, than it probably more than sharp enough.

Wanna sharpen my mower blades???

I don't think it needs to be sharp enough to cut the hairs on your arm. I never really thought about a test for sharpness of a mower blade. Sounds reasonable that you could test with some grass blades pulled from the lawn. If you get a clean cut, then you are probably ready to go mow. A good test for knowing when to sharpen blades is when grass looks like it is getting chewed off rather than cut. This leaves the grass blades open for disease. A sharp blade will make a clean cut that quickly seals and keeps out disease.

For mower blade sharpening tips on our DIY.com website go to http://doityourself.com/outdoorpower/sharpenmowerblade.htm

I know, a loaded question. But... after I sharpen my blade, I can tell a real difference, similar to putting a new razor blade in. The mower pushes much easier. So you can work at sharpening, or work at pushing.

As far as a "sharp" test, try GENTLY sliding the blade down a finger nail. Sharp will not slide, but rather dig in. Remember, GENTLY! Another way is to look at the edge in bright light. If you see any of the edge reflecting back, it's not sharp.

Happy mowing.

Mower blade sharpening has been taken to a much higher level than that of years ago. Almost to the point of a science. Todays mowers are designed to multiple cut the grass blades. (Grass Cuttings/Clippings)

The decks of todays mowers are designed with a domed and/or crowned designed. This design is there to provide space for the cuttings/clippings to be flipped upwards well above the rotating cutting blade.

As the clippings/cuttings fall back down, they are recut multiple times. Providing a mulching effect. Therefore, not fully discharging all of the clippings/cuttings into the grass catcher. Some are left behind to degrade into a natural fertilizer.

Thus, the blade and deck design each play a part in how the cuttings are handled, once the cut is made. A mowers blade angles and cutting surfaces are designed into the cutting method and process. The cutting angle and edge are very important. More so than simply the blades sharpness.

A dull blade will sever the grass blades. Leaving the grasses tiny veins sticking upwards. A day or so later, the grass will appear brown or slightly browned out. A sharp mower blade will create a straight clean scissor like cut. Reducing the browning or eliminating the browning effect all together.

To obtain a more perfect resharpening, follow and maintain the original angle on the straight edge of the blade. If there is a curved edge inwards towards the center of the blade, follow and maintain that angle also. The intent is keep the blade cutting as it was originally designed to. Which allows the deck to also do it's part and not leave stringy grass blade veins behind.

How sharp is sharp? Good question. The answer is not too sharp. An overly sharpened blade will dull much faster than one that is just sharpened to be be sharp. The angle must be maintained and the edge not razor sharp.

All that is needed on the outer most cutting edge when resharpening is to cleanup the dulled cutting edged surface, while maintaining the original upwards sloping angle. The inner angled cutting surface can be resharpend on a belt sander. As can the straight cutting edge.

Once the cutting surfaces are cleaned up (resurfaced) to be sharp, balance the blade and reinstall it as it was originally installed.

Sharpen the blade once prior to first grass growing season. Than, once at the end or near the end of the growing season, for best results, on average.

DIY Web Sites Mower Blade Sharpening Link:
http://doityourself.com/lawn/sharpmowerblade.htm

Regards and Good Luck. Sharpening Forum Moderator, Web Site Host & Forums Monitor. Accurate Power Equipment Company. Complete Saw and Tool Sharpening Service.

Reminder: "Work Shop Safety Is No Accident."

Sharpeners Quote:
"I can sharpen almost anything, except a dull mind."...:D

Prior archived posts pertaining to mower blade sharpening:

http://forum.doityourself.com/showthread.php?t=162551

http://forum.doityourself.com/showthread.php?t=134329

http://forum.doityourself.com/showthread.php?t=106391

http://forum.doityourself.com/showthread.php?t=96165

http://forum.doityourself.com/showthread.php?t=85692

http://forum.doityourself.com/showthread.php?t=78220

http://forum.doityourself.com/showthread.php?t=64951

http://forum.doityourself.com/showthread.php?p=176973

http://forum.doityourself.com/showthread.php?p=62699