In a blasting installation, surface quality and operating cost weigh the same. And the cost is dominated by a single consumable: the abrasive.

Reference figures

Ideal consumption varies widely between applications. Orders of magnitude:

Application	Indicative consumption
Steel and cast iron	5–7 kg / tonne
Forgings	4–6 kg / tonne
Steel plate and structural steelwork	2–4 kg / tonne

The figures change with how contaminated the parts are, with their size, and with the required surface quality. Use them as a reference point, not as a guarantee.

If you are far above, you have a problem. Usually not with the abrasive, but with the settings or the separation.

Where the money goes

Operating cost is not only the abrasive. In a blasting installation, the usual split looks like this:

Where the money goes	Share
Labour	33%
Maintenance	22%
Depreciation	20%
Abrasive	13%
Energy	12%

Here is the figure that changes buying decisions: abrasive is 13% of the cost. Pick a cheaper one and the most you can win is part of those 13%.

Except the wrong abrasive cleans slower, so labour goes up. It wears the machine faster, so maintenance goes up. It needs more passes, so energy goes up. A badly chosen abrasive does not affect 13% of your cost — it touches all 100%.

Which is why a badly maintained machine costs twice: once in parts, and again in the abrasive it wastes.

The shot mix

This is where most of the money is lost, and most quietly.

In a correctly set installation, the circuit holds a mix of new and worn shot, in similar proportions. New shot is added periodically, in small quantities, not in large charges.

Add too much new shot at once and the mix goes out of balance, cleaning gets worse, and consumption rises.

Wear behaviour

Round shot in low-carbon steel wears gradually. It loses its round shape as it gets smaller. The wear is slow and predictable.

Angular grit wears fast. Consumption is much higher.

The rule: if you do not need a scratched surface, do not put angular grit in the mix.

Losses through leakage

Abrasive that leaves the circuit is pure cost. Leaks appear at the separator, in the extraction system settings, and with parts that leave the machine carrying abrasive on them.

They are also a safety risk: a shot particle leaves the wheel at 70–80 m/s.

Checking for leaks is the cheapest cost reduction measure there is. It costs nothing but attention.

What you can adjust on the machine you already have

So far this has been about what you buy. This part is about what you can do without buying anything — and it usually returns more than switching abrasive.

The separator. It decides how much good abrasive stays in circulation. Set too aggressively, it throws out shot that still had life in it. Set too weakly, it leaves dust and broken particles in the mix, which clean nothing but consume energy and wear the liners. Check it with a sample from the circuit, not by eye.

The airwash. It separates dust from abrasive on the return path. Clogged or out of adjustment, the dust stays in the mix. The effect shows first in surface quality, then in consumption.

Filter condition. A blocked filter reduces extraction flow, and separation weakens with it. This is a link few people make: the dust filter directly influences abrasive consumption.

Wheel speed. More energy than the application needs does not clean better, it only breaks shot faster. A variable frequency drive allows tuning to the application instead of on-off.

Media flow. Too high, and the shot collides in the stream and breaks before reaching the part.

None of the five requires investment. All five require someone to look at them regularly.

How much abrasive you actually consume in blasting