S520. Pen Inserts (pack of 10).
This is the insert you need if you are making pen holders. It consists of metal ring with four tabs/prongs on the inside. This is a universal insert that can also be used to replace inserts that have rusted or otherwise become damaged.
Sold in packs of 10 only.
These work well to replace the insert of standard inexpensive nib holders.
I ordered these to make custom pens for my wife and some of our friends who do medieval and renaissance calligraphy. They work great in any wood that I have turned and hold the nibs securely. I have gone through the first order of 25 and will be getting more once we put a complete order together.