Frequently asked questions

Shot blasting is a mechanical surface treatment process in which abrasive particles are propelled at high speed to remove impurities, rust, paint, or other coatings from the surface of metals and other materials. The purpose of shot blasting is to achieve a clean, uniform, and roughened surface that ensures strong adhesion of paint, coating, or other protective layers. It is also used to improve the visual appearance of the surface and to prepare it for subsequent processes such as painting, galvanizing, or zinc coating.

Shot blasting is suitable for a wide range of materials, such as steel, cast iron, aluminium, stainless steel, and other metals. It can also be used for stone, concrete, glass, and similar materials when the appropriate type of abrasive is selected.

The choice of abrasive depends on the hardness and sensitivity of the workpiece, as well as on the desired final surface appearance. With the correct abrasive selection, various materials can be effectively treated without damaging the surface.

Shot blasting and grinding share a similar goal, which is cleaning or smoothing surfaces, but they differ in their methods.

In shot blasting, abrasive particles are propelled under high pressure or by a blasting wheel to strike the surface and remove impurities without direct contact between the tool and workpiece. Grinding, on the other hand, uses a contact tool such as sandpaper or a grinding wheel that mechanically abrades the surface.  Shot blasting is faster, more uniform, and better suited for complex shapes and geometries.

Would you like advice on which process is right for your product? Contact us.

Shot peening is a specialized shot blasting process in which the surface is treated with small spherical steel particles that strike it at high velocity.

This process creates compressive stresses in the surface layer of the material, which help prevent the formation and propagation of cracks.

The result is increased fatigue resistance and a longer service life of the component. Shot peening is mainly used in the aerospace and automotive industries for parts exposed to dynamic loads, such as gears, springs, shafts, and bolts.

The SA standard (SIS 05 59 00) defines the level of surface cleanliness after shot blasting:

Sa 1 – light blasting: mill scale, rust, and foreign matter are removed loosely.
Sa 2 – Thorough blasting: almost all mill scale, rust, and contaminants are removed. The surface should have a uniform greyish tone.
Sa 2 ½ - Very thorough blasting: only small traces in the form of spots or slight streaks may remain.
Sa 3 – Blast cleaning to visually clean steel: all mill scale, rust, and foreign matter are completely removed, leaving a uniform metallic colour.

The most common industrial requirement is Sa 2 ½, which ensures optimal coating adhesion and corrosion protection.

Shot blasting significantly improves the adhesion of paint, coating, or galvanic layers by creating a uniform rough surface that allows protective layers to bond more effectively.

At the same time, it removes rust, oils, oxides, and old coatings, ensuring long-lasting protection and a consistent surface appearance.

The final result depends on several factors – the type and hardness of the abrasive, the velocity of the particles, the impact density, and the degree of surface coverage. A higher impact density produces a more even roughness, which enhances coating adhesion. Other important parameters include the blasting angle, distance from the surface, and correct blasting wheel settings.

Surface quality after blasting is usually evaluated according to SA standards and the Ra roughness value, which define the level of cleanliness and the suitability of the surface for coating application.

Shot blasting does not directly change the mechanical properties of the material but improves surface cleanliness and coating adhesion. By removing rust, oxides, paint, or casting residues, the process prevents further corrosion and ensures optimal bonding of protective coatings, which results in a longer product lifespan due to enhanced corrosion resistance.

If the goal is also to strengthen the surface and increase fatigue resistance, a special process called shot peening is used. During shot peening, compressive stresses are introduced into the surface layer, which helps prevent crack formation and propagation.

The operation of a shot blasting machine is based on propelling abrasive particles at high velocity toward the surface of a workpiece using blasting wheels (turbines). When the abrasive impacts the surface, it mechanically removes rust, oxides, paint, and other contaminants, resulting in a clean and roughened surface that is ready for further processing.

In a shot blasting machine, the abrasive flows from the storage hopper into the blasting wheel, where blades accelerate and precisely direct the media into the blasting zone. After impact, the abrasive particles together with removed impurities, are collected at the bottom of the machine. They are then transported by an elevator to a separator, where impurities are removed, and clean abrasive is returned into circulation.

Because the system operates in a closed recycling loop, abrasive consumption is reduced, and the blasting quality remains consistent and repeatable. 

Abrasive exit velocity is the speed at which the abrasive particles leave the blasting wheel. It determines the impact energy and therefore the efficiency of the shot blasting process.

Higher velocity results in stronger impacts and faster cleaning, but it also increases wear on machine components. An optimal velocity ensures the right balance between blasting performance, surface quality, and the service life of the machine parts.

In shot blasting, abrasive particles are accelerated by blades inside a blasting wheel, providing high exit velocity and a uniform distribution of abrasive across the entire surface. The system is fully automated, making it ideal for large-scale production and serial processing.

Sand blasting, on the other hand, uses compressed air to propel the abrasive through a nozzle. It is suitable for smaller surfaces, manual operations, or hard-to-reach areas, but its efficiency is typically about ten times lower than that of shot blasting.

For industrial applications involving larger volumes of material, shot blasting is the optimal solution, ensuring higher productivity and consistent surface quality.

It depends on the machine size and type.

• Smaller shot blasting machines (e.g. drum/tumble or satellite / rotary-index systems): typically, no special foundation pit is required – only a level, load-bearing concrete slab.
• Larger shot blasting machines (e.g. roller conveyor shot blasting machines or hanger / monorail systems): usually require a deep foundation pit for the collection of abrasive, an elevator and a transport system.

Gostol TST prepares detailed foundation plans for each project, which ensures a safe and stable installation of the machine.

Gostol TST manufactures a wide range of shot blasting machines, fully adapted to different industries and types of workpieces:

• Roller conveyor shot blasting machine – for plates, profiles, and welded structures.
• Drum (tumble) shot blasting machines – for batch processing of small and medium-sized parts.
• Hanger and monorail shot blasting machines – for castings, welded constructions, and delicate components.
• Satellite (rotary table) shot blasting machines – for precise treatment of individual workpieces.
• Special-purpose shot blasting machines – for pipes, wires, anode blocks, natural stone, and other specific applications.

Each machine type can be customized and automated according to production requirements, ensuring optimal cleaning results and process efficiency.

Learn more about the different machine types here.

Yes. Various types of pass-through shot blasting machines – such as roller conveyor systems, pipe and round object blasting machines, and hanger or monorail machines – can be integrated into automated painting or coating lines.

These anticorrosion protection lines are typically used to apply a thin primer coating to sheets, profiles, and steel structures either for storage and processing or as a base layer before final painting.

Such an integrated system ensures efficient surface preparation and reliable corrosion protection of metal components throughout the production process. 

The service life of a shot blasting machine is typically 25-30 years or more, depending on the intensity of use, the type of abrasive, the operating environment, and regular maintenance. Gostol TST places great emphasis on robust construction, the use of wear-resistant materials, and a modular design that allows easy replacement of wear parts. Many Gostol TST machines installed more than 20 years ago are still in regular operation today.

Check out the tips on servicing and maintaining your shot blasting machine.

Gostol TST shot blasting machines are used by companies across a wide range of industries, including:

• Sheet metal, profile, and steel construction manufacturing
• Foundries and forges
• Automotive industry
• Railway industry
• Construction and agricultural machinery
• Toolmaking industry
•  Military industry
• Energy sector
• Wire and tube industry
• Shipbuilding

A Sm@rt shot blasting machine combines a classic robust mechanical design with digital control and advanced analytics.

With integrated sensors, optional monitoring modules, and the Sm@rt cloud platform, it tracks key operating parameters in real time, such as blasting wheel performance, abrasive consumption, wear of consumable parts, and alarms.

The system enables efficiency analysis, preventive maintenance, and optimization of energy and abrasive usage. The result is lower operating costs, reduced downtime, higher reliability, and a significant step toward Industry 4.0. 

The most wear-prone parts of a shot blasting machine are those directly exposed to the abrasive stream. These are primarily the blasting wheel components: blades, control cage, impeller, and shields.

Wear occurs due to intense friction and the high-speed impact of abrasive particles. The wear rate is also influenced by the type of abrasive (grit or shot), its hardness, and the blasting intensity.

Regular inspection of these parts is essential to ensure efficient blasting performance and long service life of the machine.

Regular blasting wheel monitoring includes visual inspection of the blades, impeller, control cage, and housing, as well as checking the motor amperage, which can indicate potential mechanical irregularities.

A daily visual check and recording the condition in the service book are recommended. Timely replacement of wear parts prevents vibrations and ensures stable blasting performance.

Yes. Gostol TST offers three quality classes of wear parts for blasting wheel, which differ in material and therefore in service life:

• Basic class: parts made from high-quality wear-resistant cast iron, suitable for standard operating conditions.
• Standard class: made from tool steel, providing 2-3 times longer service life. Suitable for environments with higher load intensity.
• Superior class: made from tungsten carbide and tool steel, extending service intervals by 8-16 times. Designed for the most demanding conditions where extreme wear resistance is essential.

The appropriate class is selected based on the application and the operating conditions in each specific industry. 

A magnetic air separator is used when blasting with metallic abrasives, typically in foundries or in environments where a larger amount of foundry sand and impurities mix into the abrasive.

By combining magnetic separation and airflow cleaning, it removes dust, oxide particles, and contaminants from the abrasive.

The result is cleaner abrasive, reduced wear of blasting wheels, longer machine service life, and higher blasting quality.

The replacement interval for blasting wheel blades depends on the intensity of use, the type of abrasive, and the material quality of the blades.

Under standard operating conditions, blades are typically replaced after 800 to 1200 operating hours, while blades made from Superior-class materials can reach 4000 to 5000 hours.

Gostol TST recommends regular visual inspection of the blades and monitoring blasting wheel vibrations, as increased vibration is often the first sign of uneven wear.

The service interval depends on the working environment in which the shot blasting machine operates, the type of abrasive, production capacity, and the type of workpieces.

It is recommended to service the machine every 1,200 operating hours or at least once per year. This includes an inspection of the blasting wheels, conveyors, dust collectors, and electrical components, as well as replacement of wear parts.

Regular maintenance prevents major breakdowns and ensures optimal machine performance throughout its entire service life.

Scheduling a service is easy though the contact form.

All Gostol TST shot blasting machines are designed with a strong focus on accessibility and fast, safe maintenance.

The machine layout provides easy access to the most critical components, significantly simplifying and shortening replacement times.

In addition, video instructions for replacing blades, rotors, shields, and other parts are available, as well as digital service documentation through the Sm@rt cloud platform.

This design approach enables faster service interventions, less production downtime, and lower maintenance costs.

Basic maintenance of shot blasting machine includes regular cleaning, visual inspection, and routine service tasks that keep the machine operating efficiently.

Key activities include:

• Daily cleaning and visual inspection of the machine
• Checking the blasting wheels and belt tension
• Lubricating bearings
• Monitoring dust collector condition
• Correcting minor issues as they appear

Regular execution of these tasks ensures efficient shot blasting performance, reduces wear on components, and helps prevent unexpected production downtime.

An operator should understand the machine’s basic functions, the correct start-up and shut-down procedures, the meaning of warning signals, and the essential maintenance points.

In addition, the operator must follow all safety instructions and continuously monitor the performance of key machine components.

Only a properly trained operator can ensure safe, efficient, and consistent operation of the shot blasting machine.

You can order spare parts quickly and easily:

• Through the contact information on the website https://gostol-tst.eu/services/spare-parts/
• Or directly via the Sm@rt cloud platform.

Gostol TST keeps most wear parts in stock, enabling short delivery times and preventing long production downtimes. Using original spare parts ensures the best machine performance and a longer service life.

Original Gostol TST spare parts ensure precise fit, optimal performance, and the expected service life of the machine.

Using non-original parts can lead to reduced shot blasting quality, increased wear, and the loss of warranty coverage. Original parts also help maintain the safety and stability of the entire system.

Shot blasting machines use metallic abrasives, which differ in material, grain shape, size, hardness, and composition uniformity.

The choice of abrasive depends on the material of the workpieces and the purpose of the shot blasting process, whether it is cleaning, shot peening, matt finishing, or surface preparation before further processing.

Choosing the correct abrasive ensures optimal cleaning efficiency, a consistent surface finish, and a longer service life of wear parts in the machine.

The selection of the appropriate abrasive depends on the workpiece material and the purpose of shot blasting. For products made of carbon steel or castings, steel abrasives are typically used. Products made of stainless steel should be shot blasted with stainless-steel abrasives, and the same applies to non-ferrous metals. Shot blasting should follow the principle “like with like”, meaning the abrasive should match the material of the workpiece to avoid surface contamination.

Grit has sharp edges and is therefore most effective for removing rust, oxides, and heavy contamination, but it wears out faster and causes higher machine wear. Surfaces shot blasted with grit are rougher, whereas shot produces a smoother finish. Larger grain size and higher abrasive hardness increase shot blasting efficiency but also accelerate wear of machine components and raise abrasive consumption.

For this reason, a mixture of different grain sizes or a combination of grit and shot is often used to achieve the optimal balance between blasting efficiency, surface quality, abrasive consumption, and machine longevity.

Steel grit has sharp edges, making it more effective for removing rust, oxides, and heavy contaminants, it is used when strong cleaning power and a rougher surface profile are required.

Steel shot, being round, is used when the goal is a smoother surface with lower roughness.

The choice between the two depends on the required surface quality and the next processing step.

Yes. In shot blasting machines, the abrasive is automatically recycled and returned into the system after use.

After each cycle, it passes through a separator where dust, rust, and oversized particles are removed, while the cleaned abrasive is fed back into the shot blasting process.

The grain size (granulation) directly influences the appearance and roughness of the shot blasted surface:

• Coarse grains remove more material and create roughness of Ra 50-100 µm, suitable for primers, protective coatings, and other demanding surface-preparation processes.
• Medium grains (Ra 25-50 µm) are used for surface preparation before painting.
• Fine grains (Ra 10-25 µm) produce a smoother finish and are used for finishing operations or preparation before galvanizing.

Choosing the correct grain size is therefore crucial to achieving the proper adhesion and a high-quality final surface appearance.

Gostol TST reduces energy consumption through optimized blasting wheel design, efficient abrasive return systems, and advanced machine control.

Modern ir sm@rt blasting wheels feature optimized blade geometry and housing design that ensure an even abrasive flowwith minimal energy losses, providing a higher throwing effect at the same power input. The entire shot blasting system is engineered to allow precise control of abrasive flow and blasting wheel performance based on machine load. This reduces energy consumption and component wear during individual blasting cycles. 

The choice of the blasting wheel has a significant impact on blasting efficiency, energy consumption, and surface uniformity. Blasting wheels with higher throwing speed increase the impact energy of the abrasive, enabling faster cleaning, but they also increase wear on machine components.

ir sm@rt blasting wheels are designed to deliver the same throwing speed with lower energy consumption, while maintaining an even abrasive distribution and long-term reliability. By selecting the appropriate blasting wheel for the machine type and workpiece characteristic, it is possible to achieve the optimal balance between efficiency, energy consumption, and maintenance requirements.

Sm@rt solutions enable real-time monitoring of machine operation and the shot blasting process. The system collects and analyses data on energy consumption, abrasive usage, operating hours, and the condition of key components.

Through the Sm@rt cloud platform, users have access to all essential information in real time, allowing better process management, optimized maintenance, and reduced operating costs.

By digitalizing the shot blasting process, Gostol TST increases energy efficiency, operational reliability, and sustainable resource use throughout the entire lifecycle of the machine. 

A shot blasting machine has minimal environmental impact, as it operates in a closed cycle. The abrasive is not released into the environment, it is continuously recycled and cleaned inside the machine, while the filtration system captures dust and fine particles.

Gostol TST integrates energy-efficient fans and advanced dust collector units that ensure dust emissions remain well below legal limits.

With continuous monitoring of airflow and differential pressure, a consistently clean and safer working environment is maintained. 

The dust collector system in Gostol TST shot blasting machines is designed to efficiently remove dust and particles generated during the shot blasting process.

Dusty air from the blasting chamber is drawn through the pipeline into the dust collector unit, where particles are captured on the surface of the dust collector cartridges. The cleaned air is then returned either to the environment or back into the workspace.

The systems are equipped with automatic dust collector cartridge cleaning, ensuring consistent filtration performance, stable airflow, and longer cartridge service life.

Thanks to high filtration efficiency and closed air circuits, dust emissions remain within legally prescribed limits and do not negatively affect the environment or the operator’s working conditions.

The Sm@rt cloud platform is Gostol TST’s digital solution for monitoring, analysing, and optimizing the performance of shot blasting machines.

The platform collects real-time machine data and displays it in a clear, user-friendly web interface.

It allows users to monitor key parameters and control the production process, helping improve workflow organization and reduce unplanned downtime. The platform is suitable for both new machines and some existing Gostol TST machine. By using the Sm@rt cloud platform, companies achieve lower energy and abrasive consumption, higher efficiency, and better maintenance planning, fully aligned with the principles of Industry 4.0. 

The Sm@rt cloud platform enables real-time monitoring of key operating parameters of the shot blasting machine.

Through the web interface, the user can track:

• Machine operating status
• Blasting cycle times
• Energy consumption
• Abrasive consumption
• Performance of individual components

By recording data and visualizing trends, the platform supports easier maintenance planning and better decision-making for process optimization.

Yes, the Sm@rt cloud platform provides insight into abrasive consumption and overall machine performance, making it easier to monitor wear levels and plan replacements.

By continuously recording data, the platform helps identify deviations that may affect shot blasting efficiency or surface quality.

This enables predictive maintenance, fewer downtime events, and lower material consumption throughout the machine’s entire lifecycle.

The Sm@rt valve is part of the modern abrasive-flow control system. It works in connection with the machine’s control system and enables precise dosing of abrasive according to the process settings. This ensures consistent surface treatment, reduced abrasive losses, and higher repeatability of results.

Within the Sm@rt cloud platform, data on the valve’s performance is collected and analysed together with other shot blasting parameters, enabling continuous process optimization.

Yes, the Sm@rt cloud platform enables remote monitoring of shot blasting machines and provides automatic notifications about errors and warnings.

This approach allows faster problem detection, reduces downtime, and increases overall operational reliability. 

The installation of the shot blasting machine is supervised by the Gostol TST team of experts, who ensure the correct positioning, connection, and start-up of the equipment.

After installation, a functional test is performed, followed by operator training for safe and efficient machine use.

The goal is to ensure that the machine operates according to technical specifications and the user if fully familiar with its operation and maintenance.

The pre-acceptance test (FAT – Factory Acceptance Test) is carried out in the Gostol TST production hall before the machine is shipped.

During the test, all main machine functions, basic settings, and shot blasting performance are checked.

The customer can participate in the test and verify whether the machine meets the agreed technical requirements.

After the successful FAT, a pre-acceptance report is prepared, and the machine is ready for delivery and installation at the customer’s site.

Gostol TST has an organized service support system that ensures a fast response once an issue is reported. All service requests and claims are submitted exclusively through the online form, which allows immediate assignment of the case to the appropriate expert and ensures faster processing. The approach provides an efficient and traceable claims-handling process and results in shorter response times.

Regular maintenance is performed in accordance with the manufacturer’s recommendations specified in the operating manual.

Daily preventive maintenance and routine inspections are carried out by the user’s trained personnel, while more complex service tasks are performed by Gostol TST authorized service technicians.

Regular maintenance ensures a longer machine lifetime, lower abrasive consumption, and consistently high shot blasting quality. 

The warranty conditions are defined in the sales contract that accompanies each delivered shot blasting machine.

The warranty covers defects in materials and workmanship within the specified warranty period, provided that regular maintenance is performed and original spare parts are used.

For detailed conditions and the exact warranty duration, the user can contact the after-sales department.

Contact:
Alenka Lapanja
E: alenka.lapanja@gostol-tst.eu 
T: 00386 5 380 13 03

Yes, Gostol TST offers maintenance agreements that include regular servicing, annual inspections, and the use of original spare parts to ensure optimal operation of shot blasting machines.

Inspections are carried out every 1,200 operating hours or at least once per year, in accordance with the manufacturer’s instructions and the machine’s service book. The customer also has access to an online service book through the Sm@rt cloud platform, where they can track service history, part replacements, and completed inspections.

Gostol TST also offers the options of extended warranty, provided that maintenance is performed according to the contract and original manufacturer spare parts are used.

Such a contract ensures longer machine lifetime, more reliable operation, and predictable maintenance costs.

Yes, through the Sm@rt cloud platform it is possible to record and review the complete service history of shot blasting machine.

Users can access information about completed services and replaced parts, enabling better maintenance planning and full traceability of all interventions. This ensures greater transparency and optimization of the entire maintenance process.

Yes, all Gostol TST shot blasting machines are manufactured in accordance with European standards and carry the CE mark, confirming that they meet all safety, quality, and compliance requirements.

Before shipment, each machine is inspected and tested by the Gostol TST expert team, which performs quality control and functional testing to ensure safe operation and full compliance with EU regulations.

Yes, Gostol TST has its own R&D department and in-house production in Slovenia, where all types of shot blasting machines are manufactured, from standard models to fully customized solutions.

The company develops and produces all key components, which ensures full quality control and continuous technical innovation.

All machines are the result of in-house expertise, many years of experience, and cooperation with industrial partners worldwide.

Gostol TST has more than 2,500 references worldwide across various industrial sectors, from foundries, steelworks, and metal-processing plants to manufacturers of automotive parts, wire products, and steel structures.

Many references include complex shot blasting lines, automated systems, and fully customized solutions.

These references confirm its reliability, quality, and long-standing presence on the global market. 

Gostol TST shot blasting machines operate in numerous industrial facilities worldwide, from European foundries and steelworks to manufacturers of automotive parts, steel structures, and wire products in other regions.

The company builds trust through a global network of partners, providing users with local support, reliable service, and technical expertise regardless of their location.

With several decades of market presence, Gostol TST has proven to be a dependable partner for metal surface treatment solutions around the world.

The story of Gostol TST dates back to 1947, when a small mechanical workshop was founded. Over the decades, it grew from a local craft business into an internationally recognized manufacturer of shot blasting machines and complete surface-treatment solutions.

Since the establishment of Gostol TST in its current form in 1992, the company has successfully combined tradition, in-house expertise, and innovation, enabling steady growth and a strong global presence. With more than 75 years of experience in developing and manufacturing industrial systems, the company has built a solid foundation of trust, quality, and long-term partnership with customers worldwide.

Gostol TST remains loyal to its Slovenian roots while setting future standards in metal surface treatment through technological innovation, smart solutions, and comprehensive services. 

You can get in touch with us through the online contact form or by email at info@gostol-tst.eu.

For service requests and claims, please use the dedicated form which ensures faster processing and immediate forwarding to the appropriate specialist.

We are also available by phone or through our official representatives worldwide.