Blade question

[dstoots 0]

I have a 42" side discharge mower deck. I need to know what size blades I need, the ones on it now do not overlap which brings up the second question. What position do the blades need to be installed relative to each other? Do the blades overlap? I can send picture of deck to help identify it.

[Wyattrrp 59]

My 42 inch SD deck blades are all equal length at 13-3/4 inch x 2 inch wide, ,at least on a 1981 and a 2001 I have. Unless you have blades that are too short for that model, the middle blade circle does overlap both outer blade circles a small amount even though when you look at the blades when the deck is upside down and spin them they do not appear to. The middle blade is in front of the other 2 which are equal distance toward the rear. One being in front of the others the circles do overlap as the deck moves in the direction of travel. Drop the spinning deck to lowest wheel height and it will cut 3 separate circles in the lawn (been there done that!) with no overlapping but when the deck moves forward the rear circles overlap the front circle.

The middle spindle being in front prevents the blade tips from hitting each other or you might hear a hell of a racket if they in fact overlapped when stationary. I know from the time the deck surface rusted through and let the middle spindle tip and move back enough to let the blades hit each other. Nearly jumped off the seat it made such a racket.

If you do the math 3 blades at 13.75 inches adds to 41.25 inches width not 42". With some overlap of the blade circles I assume the actual cut width might be about 39 or 40 inches and the deck width is maybe 42"?

[TT-(Moderator) 1,129]

Here's a 'drawing' I did a while ago that helps show the overlap:

Effective blade length should be measured diagonally - from corner to corner at the cutting edge, across the center of the mounting hole.

As material is ground away during sharpening, that distance decreases - resulting in a smaller 'cut circle' and less overlap. Eventually you'll end up with narrow strips of uncut grass ~ especially when turning.