Tools for grinding and polishing natural stone. Here you will find everything you need to work on natural stone.
Natural Stone Processing – Professional Grinding and Polishing
A high-quality natural stone floor adds timeless elegance and value to any room. However, over time, wear, scratches, weathering and dirt can diminish its shine – whether indoors or outdoors. To restore its original appearance and preserve the stone’s long-term value, proper surface treatment is essential. This includes cleaning, grinding and finally polishing.
With professional machines and tools from Karl Dahm, these steps can be carried out safely, efficiently and with top-quality results.
Grinding and Polishing – The Stages of Natural Stone Refinement
Surface processing is carried out in several passes, with each step using finer abrasives. The goal is to achieve a smooth, clean, and visually flawless surface. The following stages are essential:
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Rough grinding: Removes uneven spots, scratches and dirt
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Plane grinding: Levels the surface by removing any lippage between adjacent tiles
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Fine grinding / polishing: Produces a smooth, reflective surface
The choice of grit size, grinding disc and machine is crucial. Karl Dahm offers a full range of solutions for each step.
Grinding and Polishing Machines – Professional Results on Stone
For large areas of natural stone, electric or cordless grinding and polishing machines are the best choice. They save time and ensure even results:
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KD 55 Grinding Machine (Item No. 40111) – Our powerful base unit for large surfaces, compatible with accessories like weight kits, water tanks and brushes
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Item No. 40115 – Water tank for KD 55 for grinding, cleaning, polishing and shampooing
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Item No. 40291 – Cordless angle grinder, 125 mm, with variable speed, lightweight and ergonomic
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Item No. 40264 – Electric angle grinder, 115 mm, with adjustable speed – ideal for fine polishing work
All machines are compatible with a wide range of accessories and abrasive tools.
Safety Tips for Grinding and Polishing
Working with high-speed rotating grinding tools requires appropriate safety gear. Always wear:
Avoid exceeding recommended speeds. Grinding should only be done with a variable speed angle grinder at max. 2,500 rpm (e.g. Item No. 40264).
Grinding Tools & Accessories – A System that Fits
Every task requires the right tools. Different materials and surface goals call for specific abrasives, pads and backing plates. Karl Dahm provides tested kits and accessories:
Grinding disc sets and accessories:
Backing plates and holders:
Hand tools for localised work:
KD 55 accessories:
Professional-grade grinding discs:
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Item No. 50 470–50 477 – Hexagonal diamond grinding and polishing discs (grit 50–10,000)
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Item No. 50 724 – Complete disc kit with 8 discs and aluminium backing plate
Choosing the Right Grinding Disc
Grinding discs are rotating abrasive wheels mounted to machines. Different materials and surface requirements call for specific disc types:
Rule of thumb: Hard stone materials are best processed with softer grinding discs, which expose fresh cutting edges more easily. Softer materials require harder discs to ensure long-lasting performance.
Maintenance and Longevity of Machines
Even the best equipment requires care. Clean your machine regularly, check the condition of your abrasives and replace worn items in time. This guarantees optimal performance and durability.
FAQ Natural Stone Processing – Grinding, Polishing & Accessories Explained
Which grinding machine is suitable for natural stone?
For large and continuous natural stone surfaces such as floors or slabs, a robust floor grinding machine like the KD 55 is ideal because it delivers even results and high efficiency. For smaller surfaces, edges, or stairs, a variable-speed angle grinder offers precise and flexible handling.
Choosing the right machine for natural stone grinding depends on the size of the surface and the desired finish. For large floor areas, terraces, or countertops, a professional floor grinder provides stable pressure and consistent surface leveling. For more detailed work on edges, steps, window sills, or small repair zones, a variable-speed angle grinder is more suitable due to its maneuverability. It is essential that the machine is compatible with diamond grinding discs designed for natural stone.
Which grit should I use?
For coarse grinding, use grit K30–K60. For fine grinding, start at K200 and above. For high-quality polishing, choose K400–K800 or higher.
The grit level determines how much material is removed from the natural stone surface. Coarse grits (K30–K60) are used for removing unevenness and strong surface texture. Fine grinding begins at K200–K400, refining the surface structure. For a smooth, glossy polished finish, very fine grits (K400–K800+) are used. The higher the grit number, the smoother and more reflective the final surface becomes.
Can I grind stone by hand?
Yes, hand grinding works well for small corrections, edges, or raised areas. For large surfaces, a machine is strongly recommended for better uniformity and efficiency.
Hand grinding natural stone is useful for working on small, localized areas such as edges, corners, chip repairs, or slight height differences. For this purpose, diamond hand pads of different grit levels are ideal. However, for large areas like floors and staircases, machine grinding is much more efficient and produces a more uniform surface finish while saving significant time and effort.
How do I maintain my grinding machine?
Clean the machine after each use, remove stone dust, and check moving parts. Replace worn grinding discs early and store the machine clean and dry.
Proper grinding machine maintenance ensures long-lasting performance and consistent results. After each use, remove stone residue, water deposits, and grinding dust, as these can damage bearings and drive components. Inspect the backing plate and diamond discs regularly, and replace worn tools to prevent overheating or uneven grinding. Always store the machine in a dry, protected environment to avoid corrosion and mechanical wear.
How do I choose the right accessories?
Accessories must match the machine type, stone material, and desired finish. Using a product filter or consulting a specialist makes selection easier.
To achieve the best results, grinding discs, polishing pads, diamond segments, and backing plates must be compatible with your machine and the stone type. Different stones such as granite, marble, and engineered stone react differently to abrasive pressure and heat. The desired result (leveling, fine grinding, or high-gloss polishing) also plays a role. Product filters and professional technical support can significantly simplify the selection process.
How long does a grinding disc last?
The lifespan depends on stone hardness, working pressure, surface size, and disc quality. High-quality diamond discs offer a noticeably longer service life.
The service life of a diamond grinding disc varies depending on the density and hardness of the stone (e.g., soft marble vs. hard granite), the size of the area being processed, and the grinding technique. Premium diamond discs, such as Hexagonal Series discs, feature optimized diamond bonding that ensures high durability and efficient grinding performance. Using water during grinding can further increase the lifespan.
Can I combine wet and dry grinding?
Yes—if the machine and grinding discs are rated for both methods. Wet grinding reduces heat and dust, improving both tool life and finish quality.
Both wet and dry grinding are common in natural stone finishing. Wet grinding is preferred for dust reduction and disc cooling, producing a smoother finish. Dry grinding allows greater mobility and easier handling in small or hard-to-reach areas. When switching between methods, ensure the machine and diamond discs are certified for both to avoid damage or safety risks.
Which grinding tools are best for marble?
Use finer grits and soft-bond diamond tools to avoid scratches and surface damage on marble.
Marble is a soft and sensitive natural stone, susceptible to scratching and pressure marks. Therefore, soft-bond diamond pads with higher grit levels should be used to gently refine the surface. For a polished mirror finish, grits from K400 up to K3000+ provide excellent results and enhance marble’s natural depth and shine.
Which machine is suitable for outdoor stairs or patio slabs?
A powerful variable-speed angle grinder combined with durable diamond grinding discs designed for harder outdoor stone is ideal.
Outdoor stone surfaces such as patio slabs and garden steps are typically harder and more textured. A variable-speed angle grinder used with long-life diamond grinding discs (e.g., Hexagonal Series) allows efficient material removal and a consistent grinding pattern. The variable speed helps control heat, reduce dust, and improve handling.
Can I use the same pads for polishing and grinding?
No. Grinding pads remove material, while polishing pads refine and shine the surface. Each serves a different purpose.
Grinding shapes the surface and removes unevenness, while polishing seals the pores and produces a reflective finish. Grinding pads use coarser abrasive structures, whereas polishing pads use ultra-fine diamond grains. Mixing them leads to poor surface results. For professional stone finishing, always use specific pads for each step.
What is surface leveling (planar grinding)?
Planar grinding removes height differences and uneven joints, creating a perfectly flat surface.
During planar grinding, raised areas and transitions between individual stone tiles are completely removed. The goal is to produce a uniform, even surface that serves as the foundation for fine grinding and polishing. This process is essential in floor restoration, renovation, and stone installation work.
What does grit mean?
Grit refers to the size of the abrasive particles in a grinding or polishing tool.
A low grit number (e.g., K30) indicates coarse grain size used for strong material removal. A high grit number (e.g., K800+) indicates a fine abrasive, producing smooth surfaces and gloss. Choosing the correct grit level ensures that the stone is processed safely and effectively.
What is a diamond grinding disc?
A grinding disc that uses industrial diamonds to efficiently grind hard natural stone surfaces.
Diamond grinding discs consist of a metal or resin base embedded with synthetic industrial diamonds. These are extremely hard and allow fast, precise, and long-lasting grinding performance, especially on granite, marble, basalt, and porcelain stoneware.
What does polishing mean?
Polishing refines the stone surface until it develops a visible shine.
During stone polishing, the surface is gradually refined using very fine diamond polishing pads, reducing surface roughness until light reflects smoothly. Water or polishing agents assist in cooling and micro-abrasion, resulting in a high-gloss, elegant natural stone finish.
What is a backing plate?
The backing plate connects the machine to the grinding or polishing pad and ensures stable, controlled tool movement.
The backing plate (also called a support plate) transfers the machine’s rotational movement to the grinding disc or polishing pad. It stabilizes the abrasive tool, reduces vibration, and improves grinding control and surface consistency. Different stiffness levels allow customization to stone hardness and grinding pressure.
Personal Advice and Fast Delivery
Do you have questions about choosing the right machine, accessories or methods? Our expert advisors are here to help:
Phone: +49 8667 878-0
Email: info@dahm-werkzeuge.de
Take advantage of our large stock, fast shipping and professional service.
Karl Dahm – Tools for natural stone processing you can rely on.
