It's a good idea to get spare pins with a pin spanner. I've broken a spanner before by abusing it on something it wasn't quite set up to handle. I had to chuck it because the pins weren't replaceable.
When i bought a replacement spanner at my local shop (a great shop), I asked if you can replace the pins. They said yes. I said do they carry the pins? They said no. I said "I just broke one yesterday and i'm about to buy this one from you because I might break one today, and I need to replace the pins if it breaks. Will you carry the pins ?? (short check with manager) - "yes."
Anyway, you might break pins 10 or 20 years down the line, so buy spare pins while they're still in production.
- Don Gillies
San Diego, CA