Getting 30 Parts Anodized Without Paying for 300

August 12, 2026

Boutique audio lives at quantities that industrial finishing is not designed for. Thirty preamps a year is a healthy business and a rounding error to an anodizing line. The result is the most common surprise on a first production quote: the finish on a small batch costs nearly as much as the finish on a big one.

How anodizers actually price

An anodizing line is a sequence of tanks. Parts are mounted on a rack, and the rack moves through degreasing, etching, desmutting, the anodize tank, the dye tank and the seal. Each step has a fixed time. The anodize tank time is set by the required thickness, not by how many parts are in it.

So the cost drivers are:

Rack cycles. How many times a rack has to go through the line.
Racking labour. Every part is physically attached to the rack by hand, with a contact point that conducts current. Small, awkward or delicate parts take longer.
Tank time. Thicker coatings and harder coatings take longer and cost more per cycle.
Dye bath setup. A non-standard colour may need a dedicated bath, which is a setup cost on top.
Risk. A cosmetic part that can be rejected carries a scrap allowance in the price.

None of those scale with your quantity until the rack is full. That is why the curve is flat at the bottom.

Six ways to make a small batch cheaper

1. Fill the rack

Ask the finisher how many of your parts fit on one rack. Then order to that number instead of to your immediate need.

If a rack holds 120 knobs and you need 40, the extra 80 cost you material and machining but almost nothing in finishing. For a part you will use for years, this is usually the single biggest saving available.

2. Anodize the whole product family together

Panel, cover, knobs and feet in the same colour, the same thickness and the same load. One rack cycle instead of four. This also gives you the best colour match you will ever get, so it is a quality decision as much as a cost one.

3. Batch your year

Rather than anodizing 30 parts four times a year, machine 120 and anodize once. You pay for inventory instead of paying for rack cycles, and inventory of finished parts is cheap to hold and does not go out of date.

This is also the answer to the repeat order colour problem. One load means one colour.

4. Pick a standard colour

Black and clear are running on most lines most days. A custom bronze or a specific champagne may need a dedicated dye bath, a sample round and a tank that is not otherwise scheduled. If the colour is not core to the brand, a standard black costs less and repeats better.

5. Design parts that rack easily

Racking is manual labour and it scales directly with part count and awkwardness.

A blind tapped hole in a hidden face gives the racker a positive, repeatable contact point. It also means you control where the mark is.
Parts that nest or hang naturally rack faster than parts that need a custom jig.
Very small parts, below about 20 mm, are slow per piece. Consider whether they can be machined from a larger blank that racks as one piece and is separated after.

6. Ask about combined runs, carefully

Some finishers will put your parts on a rack with another customer’s parts of the same colour and specification. It is cheaper. It also means you have no control over the dye lot, the rack position or the sequence.

Acceptable for a part that stands alone. Not acceptable for a part that must match another part in your own product.

What to accept

Some costs on a small run are simply real:

A sample round. One or two parts through the line before the batch. It costs a cycle. It is far cheaper than a wrong batch of 120.
A minimum charge. Most finishers have one. Negotiating it away usually means you have found someone who will not care about the result.
A scrap allowance. On a cosmetic anodize, a small percentage will be rejected at inspection. Order a few extra rather than being short.

What to ask the finisher directly

What is the minimum charge and what does it cover
How many of my parts fit one rack
What is the standard thickness range you run and what does thicker cost
Which colours are running weekly and which need a dedicated bath
Do you keep a retained sample for repeat orders
Where will the rack marks be on my part
What happens if the batch is rejected on colour

A finisher who answers all seven clearly is one you can build a product around. That conversation is worth more than a quote comparison.

A worked example of the logic

A preamp with one panel, one cover, four knobs and four feet is ten parts per unit. At 30 units that is 300 parts, which is a real rack load even at boutique volume.

Machine all 300, anodize in one load, store them. You get:

One rack cycle instead of several
One dye lot, so every part in every unit matches
No colour drift over the year
A finish cost per unit that looks like a production quantity

The parts sit in a box for a year. That is the cheapest warehousing problem in this business.

Frequently asked questions

Why is there a minimum charge at all?

An anodizing line runs a rack through a fixed sequence of tanks with fixed times and fixed chemical consumption. A rack with 30 small parts on it costs almost the same to run as a rack with 300. The minimum charge is the cost of one rack cycle, and it exists whether you fill the rack or not.

Can I share a rack with someone else's parts?

Some finishers will combine jobs of the same colour and thickness. It lowers the price and it also means your parts share a dye bath and a rack position with parts you did not specify. For a part that has to match something, do not do it.

Is it cheaper to anodize in a different country?

Sometimes the unit price is lower, but the shipping, the lead time and the difficulty of resolving a bad batch usually erase it on small runs. Low volume work is where local finishing is most competitive.

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Keep reading

This guide is part of Finishing Audio Parts: Anodize, Brush and Blast, one of four sections in the guide library.