Generally, weapons grade fissile material is about 93% enriched, but:
FYI, people: 20% enriched U-235 is sufficient to create a bomb that will ignite an uncontrolled chain reaction, if the right bomb geometry is used and if you are willing to accept a larger bomb that may be delivered by train or ship, instead of a missile or aircraft!
IIRC to enriching to 5-20% is the time consuming part.
Enriching up to weapons grade is much faster.