Stupid question but...How often do you replace blade bolts on rotary cutter..??

[treedawg]

Tomorrow I'm pulling and sharpening the blades on my old Deere 503 rotary mower.

Not sure how old it is since I purchased it used years ago but I'd say it 30ish years old and I'm going to assume the blade bolts are original.

I searched the net and couldn't find any recommendations on how often to replace the bolts. Maybe there isn't a useful lifespan and they are to be reused until failure.

What says the experts..???

 

[japody]

If the bolts are not damaged or the blade holes are not wrung out, I see no need to replace them.

 

[Tractor Seabee]

Agree on not replacing bolts unless damaged. However, always replace those self locking bolts a lot of them have or put a castellated nut on instead, You then need to drill the bolt for a cotter pin. Once used self lockers that feature is defeated. Biggest problem is getting the **** things off to begin with. I have had to cut them off.

Ron

 

[hosspuller]

At failure, the blade is traveling x feet per second. You want to catch a 10-20 pound chunk of steel ? I replaced the blade & bolts of my 22 year old Bush hog. I did destroy one of the bolts getting it off. So I was glad I already had replacements, instead of making a second 60 mile trip.:2cents:

 

[mcfarmall]

Short answer...never. Those giant shoulder bolts would have to be nearly worn 25% or more to be a failure risk. The bolts on my King Kutter still look nearly new after 30 years of hard use. Remember, they don't pivot continuously while in use, they only pivot at startup, shutdown, or if you strike something really hard.

 

[Stimw]

This is a pic of the old and new blades for/from my 5' Woods Cutter.
My guess is they are original, I bought it (very) used.
My unit has large pins with special locks for the blades that were still good.
An old tractor Dude told me that you never sharpen them to a point, if you do then they chip.
My old blades have eaten numerous pieces of concrete rubble and were still cutting good.

 

[Suburban Plowboy]

Glad people ask questions like this.

 

[treedawg]

I pulled and sharpened my blades this evening after work. The bolts and blades looked fine. The blades were easy to remove with the assistance of an air hammer. I used my DeWalt 20 volt angle grinder to sharpen the blades. I mowed a road leading to a food plot and its cutting great.

 

[japody]

This has been discussed before, but you really shouldn't sharpen your blades to razor sharp if you are cutting fields.

 

[treedawg]

This has been discussed before, but you really shouldn't sharpen your blades to razor sharp if you are cutting fields.

What is the logic behind running dull blades..??

I didn't get them anywhere near razor sharp but I put a decent edge on them.

 

[Bird]

What is the logic behind running dull blades..??

I didn't them anywhere near razor sharp but I put a decent edge on them.

I see nothing wrong with putting a sharp edge on them IF YOU ARE ONLY GOING TO BE CUTTING GRASS AND WEEDS. But a sharp edge will get chipped, dented or bent if you hit heavier stuff. So the manufacturers know that and just simply recommend an eighth inch flat front edge (or a least the manufacturers of the two that I've owned in the past).

 

[D2Cat]

This is a pic of the old and new blades for/from my 5' Woods Cutter.
My guess is they are original, I bought it (very) used.
My unit has large pins with special locks for the blades that were still good.
An old tractor Dude told me that you never sharpen them to a point, if you do then they chip.
My old blades have eaten numerous pieces of concrete rubble and were still cutting good.

With those blades your 5' mower became a 4 1/2' mower!

 

[kthompson]

The reason I understand you do not put a sharp edge on rough cut mower if for cutting such as small trees as a sharp blade can cut leaving a sharp stump that may pierce a tire driving over it. A blade with not a true grass edge will help shatter the small tree stump helping it to rot faster and not be as likely to pierce a tire. No way I can prove that. But agree with Bird, a real sharp edge will dent and ding faster if it hits anything hard.

 

[Oldoak]

a real sharp edge will dent and ding faster if it hits anything hard.

I thought that would be "common sense" to everyone here on TBN.

Advantages to a sharp edge is that it will cut easier, cleaner, and use less HP.

 

[Cavjock22]

The reason I understand you do not put a sharp edge on rough cut mower if for cutting such as small trees as a sharp blade can cut leaving a sharp stump that may pierce a tire driving over it. A blade with not a true grass edge will help shatter the small tree stump helping it to rot faster and not be as likely to pierce a tire. No way I can prove that. But agree with Bird, a real sharp edge will dent and ding faster if it hits anything hard.

That is correct and with a little luck rain will enter the shattered branches/small stumps and rot the dern brush or woody plant

 

[japody]

What is the logic behind running dull blades..??

Several others answered this question and they are all correct. Matter of fact, I even leave the burrs and nicks in my blades because they make the blade act like a grizzly blade.

 

[AndyMA]

Tomorrow I'm pulling and sharpening the blades on my old Deere 503 rotary mower.

Not sure how old it is since I purchased it used years ago but I'd say it 30ish years old and I'm going to assume the blade bolts are original.

I searched the net and couldn't find any recommendations on how often to replace the bolts. Maybe there isn't a useful lifespan and they are to be reused until failure.

What says the experts..???

When they break

Over 20 years on one of my brush hogs

Andy

 

[DieselBound]

Blades on a 5' brush hog that I got rid of a year ago were still fine after about 6 years of hard use. I did sharpen them once, before I learned that it's really not necessary. I sold that brush hog with a new set of replacement blades. The replacement brush hog that I got (floating link and QH compatible) had blades that were totally worn out- I replaced those for about $120, which is one reason why you don't want to look to replace them prematurely (that and that it can be a fair amount of work).

I've cut "lawn" with a 5' and a 6' brush hog with non-sharp blades and the cuts are great. Heck, my actual lawn mower, though it CAN make nice cuts, tends to struggle with weeds (always have stalks sticking up which require me to back up or take another pass at); brush hogs never seem to NOT whack everything down. Scalping issues are a separate matter!

 

[Industrial Toys]

I think a good edge is still best. Someone once said that some manufacturers don't do that on account of liability.

At around 14, I found a lawn mower in a garbage. Fixed it up and my Dad took the blade to work, and had it made very sharp. I can show you the nasty scar from when my wrench slipped off and got cut, but good. I have worn gloves since, or use a smashed flat 2" piece of conduit to hold the blade.

 

[treedawg]

I understand now.....

A good sharp edge is fine but you don't want a razor thin sharp edge.