When you ask for a blasted surface, “clean” is not a specification. The preparation grade is. The standard Assessment follows ISO 8501-1, also known as the Swedish standard. The method is visual: you compare the actual surface against reference photographs. It is not an instrumental measurement. It is a comparison, made by a person, in […]
How clean is the surface: grades SA1, SA2, SA2.5 and SA3 Read More »
Before choosing the abrasive, establish what you are using it for. There are three different purposes, and they ask for different things. Surface cleaning — removing oxides, foundry sand, burrs. The most frequent case. Cutting — applied for example to granite blocks, with special mixes of hard shot. Etching — done to increase surface adhesion
How to choose shot size and hardness Read More »
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
How much abrasive you actually consume in blasting Read More »
There are two ways to throw abrasive at a part. With a centrifugal wheel, or with compressed air through a nozzle. They do the same thing. Not at the same rate, and not for the same parts. The throughput difference A wheel propels the abrasive mechanically. The blades throw it, and the energy comes straight
Wheel or air nozzle: which one, and when Read More »
Wheel blast machines differ in how the part moves in front of the wheel. Everything else follows from that: which parts you can process, and how fast. Tumble barrel Parts sit in a rotating barrel. The wheel throws the abrasive, and the parts tumble, exposing every face. For: small, robust parts in bulk. Castings, forgings,
Types of wheel blast machines Read More »
Media and compound cover most applications. Additives and special media cover the rest. Additives They are added to the bowl to reinforce one specific property. They come as liquids, pastes or powders. The effects they strengthen: grinding — stronger attack, shorter cycle polishing — better gloss at the end degreasing — parts arriving with oil
Additives and special media in vibratory finishing Read More »
The same vibratory finishing machine performs both deburring and fine grinding. The difference is not in the equipment. It is in the settings. Two movements, two effects The mix of parts and media moves in the bowl in two ways at once. Circular movement — the mix travels around the bowl. This produces a grinding
Eccentric weight adjustment: same machine, two results Read More »
Processing is finished. The bowl holds a mix of parts and media. They have to be separated. It sounds trivial. It is not — poorly planned separation means parts lost in waste, or media leaving with the shipment. The separation screen The most common method. The mix passes over a screen and the parts stay
How to separate parts from media Read More »
Compound is the part most people treat as a detail. That is an expensive mistake: both surface quality and media life depend on it. What it actually does It sets the optimum contact between media and part. Contact that is too hard means aggressive grinding. Damped contact means fine grinding. Compound is what regulates this.
Compound in vibratory finishing: what it does and how to dose it Read More »
The question comes up at every commissioning: how many parts do I put in the bowl? The answer is not “as many as fit”. Parts always represent a fraction of the media volume, and the ratio decides what kind of processing you get. The range The volumetric ratio between parts and media sits between 1:2
How many parts go in the bowl: the parts to media ratio Read More »
