Wrought iron question

[John L]

How thick would a wrought iron butt cap nut(correct word?) have to be to hold threads on ...say...1/4 x20 threaded rod? Does wrought iron tap and hold its' threads well? Thanks.

 

[John M Cohea]

I have used wrought iron for finial nuts and had no problem tapping it and the threads held fine. I suggest securing it with JB Weld unless you intend for it to be a take down model. As far as depth, as long as you have 3 or 4 good threads you should be fine. Width will depend on the size of your knife. I have made them as small as 3/8", tapped with 8-32.

 

[dbl-edge]

A rule of thumb for the thread depth is use the diameter of the screw. In your case that would be 1/4" for the most strength. Any more would not necessarily make the coupling stronger, but might help get it started during assembly. This would give you 5 threads engaged if you use a 1/4-20. However, I don't believe that this is always necessary. John's suggestion of 3-4 threads would probably hold just fine, especially if there was a good adhesive inside the handle holding it together. If you want more threads engaged, you might go with fine threads instead of coarse, say 1/4-28.

David