Laser cutting a metal blank is the default first operation in sheet fabrication because it needs no part specific tooling and produces a clean, accurate edge straight from a file. What varies between suppliers is the machine power, the assist gas they run, and how well they nest your parts, and each of those shows up in the quote in a different place.
What sets the thickness limit
Laser power and material. Higher power cuts thicker and faster, and the practical ceiling is different for mild steel, stainless and aluminium because of how each absorbs the beam and how the melt behaves. Reflective materials such as copper and brass are harder on the source. Above the laser's range, plasma and waterjet take over.
Assist gas decides the edge you get
Oxygen cutting is fast on mild steel and leaves an oxidised edge, which is fine for a part that will be painted and a problem for one that will be welded or powder coated without preparation. Nitrogen cutting leaves a bright oxide free edge suitable for welding and finishing directly, costs more in gas and runs slower. Say which one the part needs rather than leaving it to the shop.
What actually drives the price
Cutting time, which is roughly cut length plus a fixed time per pierce, so a part full of small holes costs far more than its outline suggests. Material, priced by the sheet consumed rather than the part area, which is why nesting matters enormously. And handling, since small parts have to be collected and sorted whether there are five or five hundred.
Getting a cheaper part without changing function
Reduce pierce count where holes are not needed. Keep parts nestable by avoiding awkward outlines that waste sheet. Order in quantities that fill a sheet. Accept the shop's standard material thickness. And ask whether common line cutting is possible, where adjacent parts share a cut edge and both the time and the material fall.
Questions people ask about metal laser cutting
How thick can a laser cut?
It depends on machine power and material. Modern high power machines cut substantial thicknesses in mild steel and less in stainless and aluminium. Ask the shop for their range in your material.
Why is my edge black?
Because it was cut with oxygen assist, which is fast and leaves an oxide layer. Nitrogen cutting gives a bright edge at a higher cost, and it is what to specify if the part is welded or coated without preparation.
Why do holes cost so much?
Each hole needs a pierce, which takes a fixed time regardless of hole size. A plate with many small holes can spend more time piercing than cutting.
Does laser cutting harden the edge?
It leaves a narrow heat affected zone that can be slightly harder than the parent material. It rarely matters, but it can affect subsequent forming very close to the edge.