CNC Machined Aluminium Alloy Tube with Drilled Holes and Squared Ends for Equipment Assemblies

CNC Machined Aluminium Alloy Tube

A CNC machined aluminium alloy tube is a tube that has been cut, drilled and finished on numerically controlled equipment so that its holes, ends and other features match a drawing rather than a general description. The starting point is a length of extruded or drawn tube in an aluminium alloy, and the machining operations turn that length into a part that can be bolted into a larger assembly.

Working from a Drawing

Machined tube parts are almost always made to a drawing, because the position of a hole is only useful if it lines up with the hole or the thread on the part it meets. The drawing sets the tube diameter and wall thickness, the overall length, the position and size of each hole, the angle of any cross-drilling, and the way the ends are prepared. Where two features relate to one another, the drawing should also say which one is taken as the reference, so that the part is measured the same way by everyone involved.

Machining Behaviour

Aluminium machines quickly and produces a continuous chip that must be cleared from the cut, so tool geometry and coolant are chosen to suit the alloy rather than copied from a steel job. Heat is the other consideration: aluminium conducts heat away from the cutting edge well but expands as it warms, so a part measured while it is still hot can read differently once it has cooled. Light finishing cuts and a pause before the final check are common ways of dealing with that.

Checks that Matter

Hole position, hole diameter, end squareness and overall length are the dimensions most often checked on a machined tube. A pin gauge pushed through a finished hole shows at once whether the drill stayed on line, and standing the part on a surface plate reveals any lean at the ends. Burrs are removed from every drilled edge, inside and out, because the inside of a tube is difficult to reach once the part is assembled into a frame.

Where It Is Used

Parts of this kind are found in equipment frames and machine guards, in brackets and spacers that set the distance between two panels, in handles and rails that have to be fastened at fixed points, and in the tubular members of carts, stands and display structures. They suit any assembly where a light tube has to connect to something else at an exact place.

Ordering Notes

A clear enquiry includes the drawing or model, the alloy and temper if they are fixed, the quantity, and any inspection the buyer intends to carry out. It is also worth saying which surfaces will be visible once the part is installed and whether the cut ends must be free of marks, because that decides how the parts are handled between operations.