Find Closest Part Selecting All Parts?

Hi, I'm a bit rusty at scripting at the moment and I'm trying to make a closest part script.The problem is that it selects all the parts and not the closest one. Here's the script:

while wait() do
    for i,v in pairs(workspace:GetChildren()) do
        if v ~= script.Parent and v ~= workspace.Baseplate and v.ClassName == script.Parent.ClassName then
            local mag = (script.Parent.Position - v.Position).magnitude
            if mag <= 50 then
                print(v.Name)
            end 
        end
    end
end

Any help is appreciated