No, absolutely not.
SAE30
If it is a Briggs engine it takes SAE30. If it is a Kohler engine it takes 10W-30.
any 10W-30 Motor Oil
The owner's manual for Oakes Man. L600 recommends using SAE30 motor oil in the chain cases.
Sae30 motor oil will fix it
The user's guide to my 130 series B&S engine (garden cultivator) says: 10W-40 can be used if 10W-30 is not available at your location. So, if you fit to the 10W-30 oil temperature interval then 10W-40 can be used. On the other hand lawnmower is usually used at spring-summer temperatures so why not to use SAE30 oil?
Viscosity. 5W-30 is a "thinner" oil than 10W-40 is.
regular 10w 30 motor oil
The user's guide to my 130 series B&S engine (garden cultivator) says: 10W-40 can be used if 10W-30 is not available at your location. So, if you fit to the 10W-30 oil temperature interval then 10W-40 probably can be used. I have been using SAE30 up to now. Now I am planning to switch to 10W-40 as I want to use the machine in the winter as well.
10w-40
10w 30