Blade for lawn tractor mower mower A: 558mm B: 17.5x24mm C: 7.5mm D: 63.5mm E: 5mm F: 63mm A: diagonal blade length B: centre hole dia. C: centre hole dia. D: centre hole dia. D: centre hole dia. E: blade thickness F: blade width MTD Code: R320129 Original code: 7420742 9420742 AT