DETAILED SPECS - Our Wood Chipper Blades are designed for the Landworks or SuperHandy Mini Steel Wood Chipper; The blades have a dimension of 4.15"L (105.4mm)(or 4-5/32) x 1.33"W (33.7mm) (or 1-21/64) x 0.18"H (4.5mm) (or 3/16) inches; Each blade weighs 0.22lbs / 3.6 ounces. These blades have a Center-to-Center (Outer Holes) length of 3.16" inch and a Center-to-Center (Inner to Outer Hole) length of 1.55" inch, with an Inner bolt diameter of Ø8.7mm and Outer bolt edge is Ø12.3mm | EFFICIENT RESILIENT DESIGN - These Chipper blades are precision manufactured to be mounted with (3) bolts holding each blade into place (Note: the bolts are not flat but slanted at 10.9 degrees); We chose a very strong and long-lasting CR12Mov Steel material for our blades, providing excellent longevity of use; Our blade edges sit at a 40 degree, for optimal chipping capability