Flat bar 3-hole

The 10mm width fits these slots exactly with no wiggle — finally a clean joint. I've already used three of them as corner braces in my frame.

The 30mm length is perfect for bridging gaps between bigger beams in my builds, and the three holes line up cleanly every time. Metal feels sturdy, no bending even when I overtightened the screws a bit.

I grabbed a handful of these for reinforcing corners and they slot in perfectly with the rest of my set. The 10mm width lines up flush with the standard beams, so nothing sits crooked. Nice sturdy little pieces.