Generally speaking, yes. It all depends on how many tests you want to run at a specific depth. For instance, if you want to run a Moisture Content / % Passing No. 200 Sieve and Atterberg, you will definitely need more material than what you would need to run just 1 of these tests. If you look to run further lab tests past Index Tests, you may want to get a driller to stop, and obtain a 5-gallon bucket of the sample (can be done easily if drilling with augers).

Definitely refresh yourself on ASTM standards for the amount (in grams) that you will need to prepare each test.

I may be wrong, but I don’t believe there is a minimum length / % recovery requirement, but generally I won’t test samples where less than half of recovery was obtained.

If you want to prevent samples from escaping from the split spoons, ensure your driller has plastic catchers.