This is organized every year, the 1st of may, at Bièvres in France by “Les amis de l’outil” (Friends of tools, a non-profit organization).

You can buy antique tools, traditional tool makers are presents and there are tool related presentations. The “International” is because there are some sellers coming from out of France.

Official web page here:

http://lesamisdeloutil.com/foire-internationale-a-loutil

They also have a tools museum open every Saturday afternoon.