"Greg Guarino" wrote in message
news
On 2/14/2017 9:04 PM, Spalted Walt wrote:
The Testing:
https://www.youtube.com/watch?v=EA-CmUvIsjg

I thought that test was interesting, and clever, but it may not tell you
all you need to know.

After I saw one of the Woodsperer's videos about tapping wood, I decided
to give it a try. I had a set of Sixties-era taps that were my Dad's.

If I remember correctly, I did my own test, tapping a 1/4"x20 thread in
some oak and then hitting the bolt with a hammer, and even a hand sledge.
It was remarkable how strong it was. Armed with that information, I used
some tapped holes in a jig I made. Now the jig was poplar, but it was
fully an inch thick, and wouldn't be required to hold with extreme force.

I found though that after I had tightened and loosened the jig a bunch of
times, the bolt felt looser in the threads. I think I could have stripped
them if I tightened the bolt to my usual "tighter than necessary" degree.

I think I'll still make use of some wood threads from time to time, but if
the application is going to require frequent loosening and tightening,
I'll use another method.

They can be greatly hardened/strengthened by applying super glue to the
threads then re-tapping.