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.
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:
Rough grinding: Removes uneven spots, scratches and dirt
Plane grinding: Levels the surface by removing any lippage between adjacent tiles
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.
For large areas of natural stone, electric or cordless grinding and polishing machines are the best choice. They save time and ensure even results:
KD 55 Grinding Machine (Item No. 40111) – Our powerful base unit for large surfaces, compatible with accessories like weight kits, water tanks and brushes
Item No. 40115 – Water tank for KD 55 for grinding, cleaning, polishing and shampooing
Item No. 40291 – Cordless angle grinder, 125 mm, with variable speed, lightweight and ergonomic
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.
Working with high-speed rotating grinding tools requires appropriate safety gear. Always wear:
Safety goggles
Work gloves
Hearing protection for extended tasks
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).
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:
Item No. 50604 – Grinding disc set
Item No. 50724 – Diamond grinding and polishing disc set
Backing plates and holders:
Item No. 40114 – Grinding plate / felt backing plate
Item No. 40113 – Drive plate / pad backing plate
Hand tools for localised work:
Item No. 50380 – Diamond hand pads
Item No. 20036 – Combination sharpening stone (coarse/fine)
KD 55 accessories:
Item No. 40116 – Soft brush
Item No. 40117 – Hard brush
Professional-grade grinding discs:
Item No. 50 470–50 477 – Hexagonal diamond grinding and polishing discs (grit 50–10,000)
Item No. 50 724 – Complete disc kit with 8 discs and aluminium backing plate
Grinding discs are rotating abrasive wheels mounted to machines. Different materials and surface requirements call for specific disc types:
Low grit values (e.g. 30–60): for aggressive material removal
High grit values (e.g. 400–800+): for fine grinding and polishing
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.
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.
Which machine is suitable for natural stone?
The KD 55 is ideal for large areas. For edges or smaller surfaces, use a variable-speed cordless angle grinder.
Which grit should I use?
Use grit 30–60 for rough grinding, grit 200+ for fine smoothing, and 400–800 or higher for polishing.
Can I grind by hand?
Yes – for small spots, use diamond hand pads. However, for large areas, a machine saves time and produces better results.
How do I care for my machine?
Clean regularly, replace abrasives when worn, and store machines in a dry, protected place.
How do I find the right accessories?
Use our online filter tool or contact our product advisors. Compatibility with the machine and material is essential.
How long does a grinding disc last?
That depends on material and use. High-quality discs like the Hexagonal series offer excellent durability.
Can I use wet and dry grinding methods together?
Yes, but ensure your machine and discs are compatible. Water reduces dust and cools the surface.
Which abrasives are best for marble?
Use fine grits and soft grinding discs to avoid damage on delicate materials like marble.
Which tool is best for outdoor stairs or patio slabs?
A variable-speed angle grinder with diamond discs (e.g. Item No. 40264) is suitable for robust materials.
Can I use the same pad for grinding and polishing?
No – use separate pads. Polishing pads have different structures and grit levels than grinding pads.
What does plane grinding mean?
This is a method used to level the surface and remove height differences ("lippage") between adjacent tiles.
What does grit mean?
Grit indicates the coarseness of abrasive material. Lower numbers mean coarser abrasives for more removal, higher numbers mean finer polishing.
What is a diamond grinding disc?
A disc embedded with industrial diamonds for working hard materials like granite, marble or porcelain.
What is polishing?
The final step that uses very fine abrasives (grit 800+) to smooth and shine the surface.
What is a backing plate?
A connector between the machine and the abrasive disc. It ensures secure attachment and transmits rotation effectively.
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.
