What are hammer knives?

[Simpleton7016 2]

Been searching the archives for a while today. I have seen several reference to adding "hammer knives" for breaking up ice. What do hammer knives look like? I did not come across any pictures. Are they aftermarket parts? Thanks in advance, Erik

[BLT 717]

I think what you are wondering about is rotary set of short fixed bars on two stage walk behind snowblowers to chew up the crusty top layer of snow before it hits the impeller. You don't see any walk behinds offering that feature that I can recall now.I haven't seen anything like it on tractor mounted blowers nor add on kits. If it would be a true type of hammer knife, the short bars would be pinned so they swivel back on the shaft while hitting the ice and chewing it up at ground level. Thats the good part. The bad part is that if there is no ice, those bars will beat and chew up the surface that you are blowing off.

[Simpleton7016 2]

Thanks Bob. Good explanation. Sounds like something I will have to make rather than find. :( Still would like to see a picture if anyone has one. Sincerely, Erik

[HubbardRA 19]

I think that the hammerknives that were mentioned are the ones used on a "flail" mower. They are usually a "T" shaped piece with sharpened edges that are attached to a piece of chain. When turning at high speed they will cut the grass and weeds. When the hit a rock or some other obstacle, they will bounce off it because they are attached by the chain. I don't have a picture of one that I could post.

[comet66 0]

I'm not familiar with the snowblower application, but I have used hammer knives on flail mowers. They allow you to mow into uneven or rocky terrain and when you hit something, the knives will fold back allowing you to stop, saving your equipment. Items 43, 63, and 68 in this illustration are a good example of the ones I have used.

[Simpleton7016 2]

Thanks John and Rod. That makes more visual sense to me now. Much appreciated. Erik