https://www.tractorsupply.com/tsc/product/national-hardware-dp5408b-end-cap-galvanized
Hillman Hardware Essentials Round Rail End Cap, Galvanized at Tractor Supply Co
The Hardware Essentials End Cap is designed for use with Trackmaster round rail. These end caps are made from steel and galvanized for lasting strength. With...
rail end cap
https://www.thisoldhouse.com/stairs/how-to-fix-a-loose-hand-railing-end-cap
How To Fix a Loose Stair Rail End Cap - This Old House
Apr 23, 2026 - Ask This Old House general contractor Tom Silva fixes an end cap on a stair railing that keeps coming loose.
how to fixrail end cap