They are most likely carbide inserts. No sharpening - replace the inserts.

Fecon makes similar equipment. Same thing, different machine powering it. They work great for clearing brushy areas.

http://www.fecon.com/applications/view/?productapplicationid=4


www.hoosierpondpros.com


http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).