Every lab that makes metal frameworks or copings has three routes: cast it, mill it, or send it out to be printed. Most labs choose the route their equipment chose for them: "we cast because we have the casting setup" or "we mill because we bought the mill." Both are reasonable. Neither is arithmetic.

Here is the arithmetic. Fill in your own numbers; the point is the structure, not our figures.

What casting actually costs

Labour. Wax-up or design, sprueing, investing, burnout, casting, devesting, cutting off the sprues and finishing. Casting is the most hands-on of the three routes, and labour is usually its largest cost.

Material. Alloy, investment and crucibles. Count the alloy that goes into sprues and buttons you do not recover.

Remakes. Porosity, an incomplete casting, a framework that does not seat because the expansion was off. Cost each remake at your full cost, not at the cost of the alloy.

What milling metal actually costs

The machine. Purchase price or lease payment, spread over its useful life. A machine sitting idle costs exactly the same as one running flat out, which is why utilisation dominates this calculation.

Discs and tooling. Cost per disc divided by the units you actually get out of it, plus burs, which wear fastest on metal. Track cost per unit, not cost per bur.

Labour and downtime. Nesting, loading, finishing, servicing, and the hours the machine is down while the work still has a due date.

Milling suits copings, bars and simpler substructures. A partial framework with clasps, rests and retentive mesh is harder to mill well than it is to print.

What sending it out to print costs

This side is simpler, and that simplicity is part of what you are buying: a per-unit price, shipping, the turnaround and the remake policy.

Published anchors are easy to find. For printed RPD frameworks, US lab-to-lab pricing typically runs in the region of $75 to $135, with domestic services quoting around $100 for a designed and finished frame. Our own printed framework is $58 in cobalt-chrome or titanium, with design and the resin model included. Standard turnaround is six business days, or four with a $40 rush.

Printing also takes the casting variables out of the job. There is no casting shrinkage to compensate for, no investment expansion to predict and no sprue to remove from a critical area. Clasps, rests, the major connector and the retentive mesh come off the plate as one piece. Copings and bridge substructures print the same way, in cobalt-chrome or Space Ti® titanium.

The variable that decides it

Volume. If you cast or mill metal every day, your fixed costs spread across many units. If you make a few frameworks a month, each one carries a large share of the equipment, the setup and the time of the person who knows the process.

This is why the answer is so often "both". Steady, routine work stays on your own bench. The overflow, the alloy you do not stock, the case with fine geometry and the week when everything arrives at once can go out.

Four questions that settle it faster than a spreadsheet

How many metal frameworks and copings do you actually make each month?
Have you costed your own labour honestly, including finishing?
What is your remake rate on this work, and who pays for a remake in each case?
What is the opportunity cost? If your technician spends the afternoon investing and devesting, what is that technician not doing, and is that worth more per hour?

Decide per category, not per lab

A more useful question than "cast, mill or send out?" is "which categories belong on our own bench?"

High-volume, routine work you already do well stays in-house. Low-volume work, fine geometry, or work that needs equipment you do not have goes out. Frameworks are the clearest example: unless you own a metal printer and run it regularly, making a framework in-house for less than a printing service charges is very hard.

Try it on one case first

Whichever way the arithmetic points, test it on real cases before you restructure anything. Send one framework or a few copings out and compare the true landed cost against your own, including the labour you did not spend.

That test is easier when a supplier does not require a volume commitment to run it. Ours does not: there is no minimum order and no tier pricing. A single framework is a normal order, which is the only way a trial like this is honest.

Metal frames and copings: cast it, mill it or send it to us to print it