January 13, 2021
Why are all lawnmower blades made of carbon steel? ever heard of a crusher or shredder that employs stainless? Of course not, that is because carbon steel is the most versatile and useful product available. It can be made brittle hard, sharpen able or malleable to suit. something that is hard to accomplish with stainless steel and its high chromium content.
For the blades we use in our trimmers and pruners we have a special requirement. We require a material that is hard to form, with excellent wear properties to hold an edge, but we also need a material that will not become brittle and crack with vibration or if it gets bent.
We chose to use a product called HARDOX. Made by the Swedish company SSAB it is specially formulated and designed for extreme service applications, a perfect fit for our goldilocks zone of toughness.
Yet a myth persists within the industry that stainless steel blades are of better quality.
We decided to perform some head to head testing between the carbon steel we use in our blades and our stainless steel competitors to demonstrate the difference in quality.
We tested the blades impact resistance, yield strength, and material buildup.
We also continued testing through the summer, running both the Munckhof and competitor blades on both Munckhof and competitor trimmers. The Munckhof blades were equal or better in all categories:
To test impact resistance we performed a simple test – shock load each blade with a hammer blow. Starting with a 1500g hammer we tested first the control parts then the blades. Our blade showed almost zero deflection so we moved up to a 3600g hammer.
For a more measurable result we tested the yield strength of each material under a hydraulic press. The result being that our blade required 16% more force to deform than the competitor product.
Some of the more curious feedback we had received from users was that the blades would build up sap and plant material on their surface at different rates. To test this we ran both blades side by side on Munckhof and competitor trimmers.
We put a culminative 50 acres of use on one set of blades and measured the buildup by weight, with the result being that both blades had the exact same amount of plant matter on them – 12 grams
I hope that we were able to give a picture of the kind of research we put into our products, both on paper and in the field. One of our biggest sources of information is operator feedback and we’d love to hear from you if you are a user of this kind of equipment.