Why tools break fast
Vein mining breaks many blocks in one action, and each block normally costs durability. Mining a large vein with a low-durability tool can destroy it in a single swing. 
Ore Excavation includes config options that change how durability is handled, so check the config before blaming the mod.
Practical steps
1. Open the mod's config file or in-game config screen.
2. Look for the durability-related option and read its description.
3. If durability is applied per block, use a tool with high durability or an unbreakable tool for large veins.
4. Consider enabling the option that limits excavation to a maximum number of 
blocks, so a huge vein cannot consume your entire tool.
5. Test on a small vein first to see how much durability one action costs.
Managing large veins
- Set a block limit so accidental mega-veins do not wipe your tool.
- Carry spare tools or repair materials when mining in ore-rich areas.
- Remember that the mod may also excavate in a radius or shape mode, which multiplies the blocks affected.
Tuning these settings lets you enjoy fast mining without losing your best pickaxe to a single vein.
