I've recently moved and after a mover handled my hydraulic jack the handle is missing a - securing pin(?) - I don't know what it is called. It looks like this and it secures a smaller diameter pipe inside a larger diameter pipe:
What is such pin/dowel called properly? Can it be purchased at a hardware store? The handle of the hydraulic jack is made up of two pipes and this pin/dowel is missing

Thanks

What is such pin/dowel called properly? Can it be purchased at a hardware store? The handle of the hydraulic jack is made up of two pipes and this pin/dowel is missing

Thanks