Oak was used extensively for construction of much bigger objects than a big crate for many, many centuries.
- The portcullis of most castles, for example, was made out of oak reinforced with iron nails.
- Solid gates were typically also made out of oak planks.
- In areas with soft ground, the soil was excavated and an enormous oak "raft" built to support an entire castle from below.
- Oak was used for Royal Navy ships for centuries. Hence "heart of oak are our ships, heart of oak are our men". The Spanish, at one point, even had a plan to set fire to the English oak forests to deprive their enemies of shipbuilding material.
As one final notation, our ancestors cut and fitted stone, including granite, with great precision and nothing but hand tools and a lot of patience and sweat. I doubt drilling through a bit of oak would daunt them compared to that.