Flail Mower Mott style flail knives

[Rowski]

Does anyone have any experience using these style flail knives. These knives fit the fine cut cuttershaft. The course cut cuttershaft blades are different and will not fit. In the above link the knife assembly on the right has a "D" ring verses the left one which doesn't.

My question is whick is better? The one with the "D" ring is classified as a rock & trash blade. The guy I bought my used flail mower from said he didn't have very good luck with the "D" ring style knives in that the "D" break often.

Also are there any replacement blades that are forged for this fine cuttershaft. I can find forged blades for the course cuttershaft.

 

[markct]

the straight style will break off just looking at them, we have a mower with the straight type, it lost almost all its teeth in a few years, they are made for mowing lawn and lawn only, the type with the d ring is what the flail we have now has, its still not good for heavy brush but it can take rocks and stuff like that without damage, for anything other than lawn you need the d ring type