Deckorators Aluminum Stair Post Connector for ALX Contemporary Series #351133

thingiverse

Replacement for Deckorators pre-assembled stair rail kits ALX Contemporary connectors, model #351133. Found at Lowes for $80+ a set (which is absolutely crazy if you cut railings in smaller sections since you need more brackets). This version uses M5 screws 35mm in length, with encapsulated M5 nut (regular or nylon lock nut would work). I've used #8 x 3/4 in sheet metal screws for both attachment to the upper and lower rails, and posts. Predrill before using the sheet metal screws. They are just the hardware I had laying around. If you use different hardware you may want to change hole diameters. The original part these are made to replace is here: https://www.lowes.com/pd/Matte-Black-Aluminum-Stair-Post-Connector/1000955520 Printed on a mark forge printer out of onyx, which matches the matte black of the railing better than even the original hardware.