Need help finding a longer nail for seam binder

I purchased a seam binder from Lowe's, and it came with 1 1/4" nails. However, these nails are too short to securely attach the seam binder to the subfloor, especially when joining carpet and hardwood flooring.

The nails that came with the seam binder nails are 1 1/4" brown screw trim nails with 3/16" heads. Unfortunately, I haven't been able to find longer nails of this type; perhaps 1 3/4" would be suitable.

I returned to Lowe's and purchased brown Panel Nails 15 GA x 1 5/8", which seemed like a viable option. However, the nail heads are too small and slip through the seam binder.

I was able to attach one seam binder (see below) but the others need longer nails for some reason.

What terms should I search for online to find the right nail?

 

I have no idea where to find longer ones and I started in this business in 1973.

 

Boy, that's going to be tough since the strip came with painted nails with a rounded, finish head. A very specific nail You might have to get nails of the length you want and paint the heads.

 

Putting the binder over the tackstrip, like it should be done, the nails should nail to the tackstrip. In fact, they may be too long if you do it right and you may need to shorten them.