A 16G needle is 1/16" OD (and 1.6mm), and depending on your part of California, are available at a pharmacy. I went yesterday to stock up on 16G and 18G, 10 each, said that I wanted the tube part for use in electronics and scored 20 16G for free as they were past there expiration date and she would have
thrown them out anyhow

The needles I paid for were about $.04 apiece.