I had the opportunity to attend a 3-day workshop with Mike Mahoney last weekend. One of the techniques he taught was making hand chased threads. Of course now that I've done it, I want to buy some thread chasing tools. Mike taught the technique with 16 threads per inch (TPI) tools because it is apparently one of the easiest thread sizes to learn. I was browsing through The Woodturners Catalog and noticed that they say 20 TPI is the most common. If I plan to make boxes with threaded lids, and hollow forms with threaded collars and finials, should I use 16, 18, or 20 TPI? Also, does anyone have an opinion about the Allan Batty thread chasers vs. the Sorby thread chasers?

On a side note, I was extremely impressed with Mike Mahoney. He's an incredible turner and has the people skills and teaching skills to match. If he's ever teaching in your area, I highly recommend taking advantage of the opportunity.