Using Plastic Threads For Lids And Finials

[Glen Blanchard]

I have heard of woodturners using a black plastic (PVC?) threaded insert in place of chasing threads or using a thread cutting jig to secure a finial to a hollow form or a lid to a box. I'd like to experiment with this technique. Anyone have a source for such things? Something in the 1" - 3" diameter range? My Google search was less than productive. The brass alternatives that I have seen are priced at $25 per so I am looking for less expensive options.

[David DeCristoforo]

Most guys use black plastic plumbing pipe fittings available from any hardware store or plumbing supply house.

A couple of tips: These fittings are designed to get tighter as they are screwed together. So it’s best to part off only the first couple of threads. They are easy to cut with standard lathe tools but use a slow speed or the plastic will melt. Also the threads are soft so some protection in the form of a few wraps of masking tape will keep them from being damaged when held in a chuck. The mating part makes a great holder for cutting the fittings down so buy a few extras.... they’re cheap.

[Len Mullin]

Glen, you can use ABS or PVC threaded pipe fittings, either one will work. Some people use both, it depends on the color of the wood.
Len

[Kyle Iwamoto]

Try Beall dies and the matching tap? That way you make the threads from wood and not plastic. Looks WAY better IMO. One time investment and you can make lots of finials.

[John Keeton]

I use the 1.5” ABS clean out plug. With ABS you do not have to worry about wood movement seizing your threads and correctly installed they look very nice.

[Richard Madden]

Glen,
Here's an old thread I posted several years ago that might help. http://www.sawmillcreek.org/showthread.php?144500-Vessel-with-threaded-lid&p=1470158

[Glen Blanchard]

Just what I was looking for. I'll have to give it a go one of these days and see how much I like the result.

Thanks everyone!

[Jack Lilley]

I use 1" brass pex fittings for smaller vessels and 3" brass shower drain for larger vessels. The two 1" fittings cost about $10 and I get the 3" brass for $18.50 but can two sets of male/female threads from it.