That is a fairly standard size, so one example might be fleabay: https://www.ebay.com/itm/300mm-1-1-2-1-3-1-5-1-6-1-8-2-2-2-2-3-2-4mm-brass-bar-rod-H62-solid-stick-baton/392466660094?var=661462066595&hash=item5b60d5fafe:m:mNqQbamL_f6YkyPWkgxtwXA(The price is on the high side compared to industrial suppliers, but then again you get to buy one or only a few at a time).