The standard t-nut layout for years has been the 72 t-nut pattern. 72 t-nuts is how many t-nuts that you will install on a 4' x 8' sheet of 3/4" ACX plywood. You would choose this pattern if you are building a school wall or a trampoline park. There are limitations with the 72 pattern as the spaces are 18" apart. That leaves a lot of open space between holds. If you want to be setting routes and boulder problems, scroll down to the 98 pattern.
Atomik recommends the 98 Hole T-nut pattern (Staggered). It gives you t-nuts that are 6" apart with each column of t-nuts staggering.
From left to right, you have a column of 7 t-nuts, then the next column is six t-nuts. You should get eight columns of 7 t-nuts (56) and seven columns of 6 t-nuts (42). Our reasoning for this density is that on a home bouldering wall, space is at its premium since most are not very big. When route setting on the standard 72 pattern, you will find significant gaps of space between holds. It is easier to set routes on the 98 t-nut pattern because you have more options in terms of the staggering locations and the higher quantity of t-nuts—the Atomik standard for bouldering walls to achieve maximum options for route setting.
The 105 t-nut pattern is for system walls. System Walls use the grid pattern. System walls need to be symmetrical with a tight t-nut spacing for the most options to be able to overlap paths. The grid pattern makes it easy to set up repeating holds/moves.