Kubota 3010 belly deck blade went flying

[CaptFerd]

Helpful video to prevent the blades falling of as your Kubota ages. Same design on zero turns, smaller tractors as well as other brands.

 

[5030]

Called a Tinnerman washer and yes, they need renewed if flattened out. They provide constant tension to the blade bolt and of course the bolt needs to be torqued to the correct value as called out in the owners manual for the deck.

 

[Sportsman762]

I always thought a tinnerman washer was a countersunk washer. A concave washer meant to apply tension to a part is a bellville washer. If made of a thinner material and used as a spring then its a belleville spring.

Belleville washer - Wikipedia

en.wikipedia.org