How Are SIP Machines Manufactured? From Steel to Reliable Grassland Harvesting Machines

SIP manufactures all its grassland harvesting machines at a single location in Šempeter in the Savinja Valley, Slovenia. SIP machine production takes place under one roof—from laser cutting, bending and welding to machining, painting, assembly, testing and preparing machines for dispatch.

This vertically integrated production model allows SIP to maintain direct control over quality, implement improvements quickly and remain highly flexible when manufacturing different machine models.

Today, SIP manufactures approximately 100 different grassland harvesting machines and manure spreaders, which are available in at least 300 different configurations with optional equipment. All SIP machines ara available with a 3-year SIP warranty withouth any hectares limitations.

What Does Vertically Integrated Production Mean at SIP?

Vertically integrated production means that SIP carries out most of the key manufacturing processes and produces the majority of essential machine components in-house. Virtually all the main production processes are connected under one roof:

• laser cutting of sheet metal and tubes,
• CNC bending and material forming,
• robotic and manual welding,
• shot blasting and surface preparation,
• KTL coating and powder coating,
• machining,
• production of essential drive components,
• machine assembly and final assembly,
• functional testing and quality control,
• installation of optional equipment,
• preparation of machines for transport.

How Is the SIP Production Process Organised?

All SIP machines are manufactured in Slovenia, in Šempeter in the Savinja Valley. This is the company’s only production site. The production facilities cover approximately 3.5 hectares, while the entire company site extends over more than eight hectares. In addition to the production departments, the site includes research and development, warehouses, logistics, pre-dispatch machine preparation and a spare-parts warehouse.

SIP combines elements of mass production and lean production:

• Mass production is mainly used to manufacture larger quantities of similar semi-finished components, for example during material cutting, sheet-metal bending, machining and the production of standard components.
• Lean production enables a fast and organised flow of semi-finished components through the different production stages. In a typical production process, a component may be welded on the first day, shot-blasted on the second day, painted on the third day and delivered to its designated assembly station on the fourth day.

To organise work more efficiently, SIP uses methods such as Kanban, 5S, SMED, TPM and visual management. Their purpose is to reduce time losses, keep workplaces organised, improve material supply and shorten production lead times.

SIP production is predominantly based on small batches. An individual production batch may include only five machines, while batches of certain machines designed for mountain farms may consist of 30 or even 50 units. This organisation provides a high level of flexibility and enables SIP to manufacture different versions and configurations according to the requirements of individual markets and customers.

Which Key Components Does SIP Manufacture In-House?

SIP develops and manufactures most of the key components used in its machines.

In-house manufactured components include:

• cutter bars,
• drive gearboxes,
• tedder and rake rotors,
• gear pairs,
• flanges,
• supporting elements,
• machined components.

Producing key components in-house allows SIP to maintain better quality control and implement technical improvements more quickly. Since SIP develops, manufactures, assembles and tests its machines at the same location, the entire process can be managed as one connected system.

When the research and development department modifies a component, the change can be transferred directly into production without the long delivery times associated with external suppliers.

The main advantages of in-house production include:

• better quality control,
• improved traceability of components,
• faster implementation of improvements,
• greater availability of spare parts,
• shorter response times,
• better compatibility between individual assemblies,
• more reliable machine operation.

How Does SIP Select Materials for Machine Production?

The production of SIP machines begins with the preparation of high-quality raw materials. SIP uses steel sheets, tubes and bars of European origin, as the quality of the material directly affects the robustness, performance and service life of the finished machine.

Material quality is a priority because machine structures must withstand high mechanical loads, vibrations and varying weather conditions during operation.

High-quality materials contribute to the robustness, reliability and long service life of SIP machines. SIP underlines this commitment by providing a three-year warranty on all machines, with no limitation on the number of hectares worked.

How Is Sheet Metal Laser-Cut?

Standard sheet metal measuring 1,500 × 3,000 millimetres is cut using four laser cutting machines. Approximately 3,400 tonnes of sheet metal are processed annually.

One of SIP’s major recent investments is a powerful 8.5-kilowatt fibre laser, which cuts material approximately three times faster than a conventional CO₂ laser. The increased speed and productivity provide sufficient production capacity to support the company’s continued growth.

Laser cutting provides:

• rapid production of different shapes,
• high dimensional accuracy,
• clean cutting edges,
• excellent repeatability,
• reduced material waste.

What Are the Advantages of Laser Tube Cutting?

A specialised tube laser enables automated cutting and machining of tubes. A single operation can replace several processes that would otherwise need to be carried out using saws, drilling machines and different machining centres.

In certain cases, one operation on the tube laser can replace as many as ten separate operations on other machines.

This method reduces the number of intermediate production stages, improves component accuracy and lowers the possibility of errors during subsequent assembly. As a result, parts are more precise, production is faster and less manual work is required.

How Does CNC Sheet-Metal Bending Work?

After laser cutting, sheet metal is formed using CNC press brakes. SIP operates five CNC bending machines of different sizes. The largest machine has a pressing force of 320 tonnes and a working table length of 4.5 metres.

CNC control enables settings to be repeated precisely, ensuring that every component within a production batch is formed identically. This is essential for correct machine assembly and for maintaining the required structural geometry.

In addition to bending, SIP also performs other material-forming operations. The largest press has a force of 400 tonnes.

How Are SIP Machines Robotically Welded?

SIP uses a combination of robotic and manual welding to manufacture welded assemblies. The production facility operates 13 welding robots. Approximately 60% of all welded assemblies are produced robotically, while the remainder are welded manually.

Robotic welding is particularly suitable for repetitive components and larger production batches. Its main advantages include:

• consistent weld quality,
• high repeatability,
• precise process control,
• greater productivity,
• reduced possibility of deviations,
• improved working conditions for employees.

SIP uses approximately 250 specialised welding fixtures for robotic welding. Each semi-finished component has a dedicated fixture that ensures the correct positioning of individual parts during the welding process.

Why Are Some Components Still Welded Manually?

Manual welding is used for complex components, smaller production batches and structures where robotic welding is not the most efficient solution due to their shape or limited accessibility.

Manual welders can adapt their work to the specific characteristics of each component. They also play an important role in producing prototypes and introducing new products.

All SIP welders hold the required A-test welding qualifications in accordance with TÜV standards and renew them regularly. The company also works closely with a welding engineer who is responsible for process development, standardisation and the continuous improvement of weld quality.

How Does SIP Control Weld Quality?

The inspection of welded assemblies is integrated directly into the production process.

The first welded component in every batch is:

• visually inspected,
• dimensionally measured,
• compared with the technical documentation,
• approved before production of the remaining batch continues.

Only after the first component has been approved can the production of the remaining welded assemblies proceed.

For more complex measurements, SIP uses a 3D measuring arm to verify geometric accuracy and the position of individual elements.

What Is Shot Blasting and Why Is It Important?

Shot blasting is a process used to clean and mechanically prepare metal surfaces before painting. During the process, small metal beads strike the surface of the workpiece at high speed.

Shot blasting removes:

• rust,
• oxidation,
• dirt and contaminants,
• residues of previous coatings,
• surface irregularities.

At the same time, the process creates a suitable surface texture that improves the adhesion of subsequent protective coatings.

SIP can shot-blast workpieces measuring up to approximately 2.5 × 2.5 × 7 metres, allowing even very large structural components to be treated.

High-quality surface preparation is essential because only a properly cleaned and treated surface provides effective corrosion protection and long-lasting paint adhesion.

How Are SIP Machines Protected Against Corrosion?

SIP uses a multi-stage surface-treatment system to protect metal components against corrosion. Shot blasting is followed by chemical pretreatment and painting. SIP combines zinc phosphating, cathodic electrodeposition coating—also known as KTL coating—and a final powder-coated finish.

The process includes:

• shot blasting,
• zinc phosphating,
• rinsing with demineralised water,
• cathodic electrodeposition or KTL coating,
• application of powder coating,
• curing the coating in an oven.

Zinc phosphating improves paint adhesion and corrosion resistance. The KTL process allows the protective layer to reach internal, concealed and difficult-to-access areas of the workpiece.

The final layer is a powder coating, which is cured at a temperature of approximately 190°C.

This process achieves corrosion resistance of at least 1,200 hours in a salt-spray chamber.

Why Does SIP Use KTL Coating?

KTL, or cathodic electrodeposition coating, is a process in which the entire metal component is immersed in a special coating bath. An electric current enables the protective coating to adhere evenly to the entire surface.

The main advantage of the KTL process is the protection it provides to:

• internal edges,
• hollow components,
• narrow joints,
• difficult-to-access surfaces,
• areas around welds.

This protection is more effective than a conventional surface coating because it reaches areas that cannot be accessed with a traditional spray gun.

When Is Wet Painting Used?

SIP uses wet painting for very large workpieces and for components that are not suitable for heating to high temperatures.

A single-layer, two-component paint is applied and dried at approximately 80°C. Wet painting is particularly suitable for large structures that cannot be treated in the standard KTL and powder-coating line.

How Is Machining Carried Out?

Machining operations are carried out using modern CNC lathes and machining centres.

SIP operates:

• 11 CNC lathes,
• three horizontal machining centres,
• two vertical machining centres,
• two five-axis machining centres.

The largest machining centre can process workpieces up to seven metres long. Some machines are equipped with robotic loading and unloading systems, increasing productivity and allowing repetitive components to be manufactured automatically.

SIP uses a highly accurate Zeiss 3D measuring machine to inspect finished components.

How Are SIP Machines Assembled?

Machines are assembled on specialised assembly lines organised according to individual product groups.

Separate assembly lines are used for:

• mowers,
• tedders,
• single-rotor rakes,
• rotors for twin- and four-rotor rakes,
• AIR pick-up rakes,
• frames for larger rakes,
• larger machines assembled on the universal production line.

Approximately 80% of the total production volume is assembled in the main assembly hall.

Once basic assembly has been completed, the machine is transferred to the pre-dispatch preparation department. Depending on the customer’s order, the selected optional and hydraulic equipment, electronic systems, wheels, lighting and road-safety equipment are installed there.

How Does SIP Monitor Production Quality?

Quality control at SIP is not limited to the final inspection. It is integrated into every stage of production—from checking incoming materials and approving the first welded component in a batch to measuring machined parts and testing fully assembled machines.

Quality control includes:

• inspection of incoming materials,
• approval of the first welded component in each batch,
• dimensional inspection,
• 3D measurements,
• inspection of surface protection,
• testing of individual assemblies,
• functional inspection of the complete machine.

Daily coordination meetings are also held to monitor production. Department managers review production output, material availability, possible defects and the situation at individual workstations.

How Does SIP Manufacture and Inspect Cutter Bars?

The cutter bar is one of the most important components of a SIP mower. SIP develops and manufactures its cutter bars in-house. Before installation, every cutter bar is inspected and tested.

The leak test is carried out in a dedicated chamber or water tank:

• The cutter bar is filled with compressed air.
• It is submerged in water.
• The housing is checked for leaks.

This verifies the leak-tightness of the housing before painting and assembly. The test reduces the possibility of oil leakage or the ingress of water and contaminants into the cutter bar.

Only a cutter bar that has successfully passed the test proceeds to the paint shop and final assembly.

Mower conditioner rollers and manure-spreader rollers are dynamically balanced on a specialised balancing machine before assembly. Precise balancing prevents vibrations during operation and reduces loads on the structure and drive components.

How Are Finished Machines Functionally Tested?

Every manufactured machine undergoes a functional inspection before dispatch. Special inspection stations are therefore integrated into the assembly lines. At these stations, the drive systems, hydraulic components, rotor rotation, noise levels, required drive power and other essential functions are checked.

On mowers, individual assemblies are tested in a dedicated test cabin. The first machine in each production batch is fully assembled, connected to a tractor and thoroughly inspected together with the quality-control department.

Larger and more complex machines may be assembled and tested for several days. Where appropriate, they are delivered to customers almost fully assembled.

Why Does SIP Deliver Larger Machines Already Assembled?

Where transport conditions allow, SIP delivers larger and more complex machines in the highest possible state of assembly. The customer receives a verified machine whose key functions have already been tested during production.

This reduces:

• the possibility of assembly errors at the customer’s premises,
• the time required to prepare the machine for initial use,
• the risk of incorrect settings,
• the possibility of subsequent warranty claims.

Logistics for More Than 55 Countries Worldwide

Approximately 30 to 40 lorries enter and leave the company site every day, either delivering raw materials or collecting finished machines.

Most machines are protected with film and packed in wooden crates or mounted on metal transport structures.

Packaging is also adapted to the requirements of distant markets such as New Zealand, Australia and the United States. For overseas deliveries, wooden or metal packaging must comply with specific import and phytosanitary requirements.

Approximately 80% of the machines manufactured by SIP are exported. SIP machines are sold in more than 55 countries worldwide, making efficient logistics and reliable documentation preparation an essential final part of the production process.

Reliable Supply of Original SIP Spare Parts

The production and logistics centre in Šempeter also includes a spare-parts warehouse. More than 12,500 different components are kept in stock, enabling SIP to supply partners and customers in over 40 countries.

Original spare parts are designed according to the technical requirements of each specific machine. SIP guarantees their availability for at least ten years after production of a particular model has ended, enabling users to maintain their machines and operate them reliably over the long term.

Rapid spare-parts delivery is especially important during the grassland harvesting season, as even a short period of downtime can affect forage quality and the timely completion of work.

Modern Technology and Employee Expertise

SIP uses modern laser cutting machines, welding robots, CNC machines, automated machining centres and advanced surface-protection processes in its production operations.

However, technology alone is not enough. The knowledge, experience and responsibility of employees also play an essential role. SIP employees:

• prepare production processes and program machines and robots,
• carry out manual welding and assemble complex components,
• monitor quality and test machines,
• implement improvements.

The combination of automation and professional expertise enables SIP to manufacture robust, efficient and reliable grassland harvesting machines.

More Content Related to SIP Production

• SIP Production
• SIP Production Services
• EMAG CLC 260 H and Gleason Phoenix 600HC Gear Manufacturing Machines
• SIP 3-Year Warranty

FAQ: Frequently Asked Questions About SIP Machine Production