Replies

1. 
   _mj_ | Jul 23, 2022 04:43pm | #1

   Only way to know is to test it. Glue up some oak and start drilling.

1. 
   Gpetto | Jul 23, 2022 05:18pm | #3

   Thanks! Going to test first!

2. 
   gulfstar | Jul 23, 2022 05:06pm | #2

   Please do test before, I never had success with mine in a 4 inch thick maple bench and thinking of plugging the hole and starting over when I find the recipe, could be a stepped hole ?

1. 
   Gpetto | Jul 23, 2022 05:19pm | #4

   Thanks! Going to test first on 5” scrap!

3. 
   _mj_ | Jul 23, 2022 05:33pm | #5

   I use record mechanical hodfasts with the cast iron collars. The hardware kits all came with screws that would cover a 2" bench, so I got longer screws. Turns out the angle the rod grips at would not work on my 3+" top. I had to recess the back plate unti the oem screws could be used.

4. 
   JEarch | Jul 23, 2022 07:03pm | #6

   It’s not just the diameter but also the length of hole that matters, since holdfasts work by wedging at a slight diagonal in the hole. The longer the hole the shallower the angle.

   I use Gramercy holdfasts in holes drilled with a 3/4” bit. The holdfasts are about 1/32” undersized, and the holes are a bit oversized, measuring 0.755”. However, to get them to grip well and not slip in my 3-1/4” thick top, I had to rough up the stems a bit with coarse sandpaper. A slightly larger hole might have worked too, but as I didn’t do a test first, plugging and redrilling or reaming out the holes would have been a challenge.

   By all means do a test, including whacking the holdfast in place to test the grip.