EDM Surface Finishing Stones – Mold Polishing Stones

Hand polishing process on a steel mold using high-performance CG-800 Silicon Carbide EDM stones to achieve a flawless mirror finish.

Technical Specifications and Grit Selection of EDM Surface Finishing Stones

FEPA Abrasive Grit SizeAverage Particle Size (µm)Target Surface Quality (Ra – µm)
120 Grit1251.6 – 2.2
220 Grit680.8 – 1.2
400 Grit350.4 – 0.6
600 Grit250.2 – 0.3
1000 Grit130.1 – 0.15

for details official FEPA website you can visit.

Selecting the correct abrasive grit size in post-EDM surface improvement processes is critical to achieving the target surface roughness (Ra) value. Generally, starting with 120 or 180 grit after rough machining, it continues until the recast layer on the surface is completely removed. Afterwards, micro-scratches on the surface are eliminated by moving to 320, 400, and 600 grit values. In the final stage, 1000 and 1200 grit stones are used for the final surface preparation of precision molds before polishing.

Material Compatibility and Hardness Performance

These aluminum oxide-based stones exhibit high performance, especially on heat-treated steels with a hardness range of 45-60 HRC (Rockwell). They can be used in a wide range of applications, from plastic mold steels like P20 to H13 hot work tool steels and D2 cold work steels. The structural integrity of the stone maintains its material removal capability without breaking, even under high pressure. This ensures the preservation of geometric precision, particularly in the sharp corners and channel details of the molds.

Operational Usage Advantages

It is recommended to use special polishing oils or kerosene during the use of stones in mold polishing processes. These fluids prevent the pores of the stone from filling (clogging) with metal dust, ensuring the continuity of cutting performance. Additionally, the removal of heat generated during the process helps to clean the recast layer more homogeneously. Thanks to its aggressive material removal feature, it offers high efficiency in manual operations as well as mechanical processes performed with pneumatic or electric hand tools.

Critical Details in the EDM Mould Polishing Stones (Makrotaş) Surface Finishing Process

The thermal damage layer formed on the surface after EDM erosion wear is quite hard and brittle. Failure to clean this layer with the correct stones, such as Edm Mould Polishing Stones, can shorten the mold's service life in subsequent stages. Our product rapidly eliminates this hardened layer without damaging the structural form of the underlying base metal. These stones, focusing on low Ra values, create a perfect substrate before final polishing.

Product Description It is a high-performance, aluminum oxide-based aggressive surface finishing and polishing stone formulated to eliminate thermal damages (recast layer/EDM scale) occurring on mold surfaces after electrical discharge machining (EDM) processes.

Key Features and Applications

  • Material Composition Our Mould Polishing Stones are produced from high-density and homogeneous aluminum oxide grains. It is the polishing stone with the highest degree of hardness and optimized wear resistance in our company's production portfolio.
  • EDM Surface Finishing Designed for the effective removal of micro-scratches and the hardened burn layer (recast layer) formed after the EDM process.
  • Application Areas It delivers superior results on heat-treated hardened steels, as well as high-alloy mold and die-casting steels (such as P20, H13, D2, etc.).
  • Processing Performance Thanks to its high structural integrity, Makrotaş EDM Mould Polishing Stones ensure high surface quality (low Ra value) without compromising geometry.

Technical Support Note This product has been developed to enhance operational efficiency, especially during pre-polishing stages that require aggressive material removal.

EAN NOSizeGritPackaging
245516 x 13 x 150 mm.120Box of 12 Pieces
245526 x 13 x 150 mm.220Box of 12 Pieces
245536 x 13 x 150 mm.320Box of 12 Pieces
245546 x 13 x 150 mm.400Box of 12 Pieces
245556 x 13 x 150 mm.600Box of 12 Pieces
245566 x 13 x 150 mm.800Box of 12 Pieces
245576 x 13 x 150 mm.1000Box of 12 Pieces
245586 x 13 x 150 mm.1200Box of 12 Pieces
EAN NOSizeGritPackaging
245593 x 13 x 150 mm.120Box of 12 Pieces
245603 x 13 x 150 mm.220Box of 12 Pieces
245613 x 13 x 150 mm.320Box of 12 Pieces
245623 x 13 x 150 mm.400Box of 12 Pieces
245633 x 13 x 150 mm.600Box of 12 Pieces
245643 x 13 x 150 mm.800Box of 12 Pieces
245653 x 13 x 150 mm.1000Box of 12 Pieces
245663 x 13 x 150 mm.1200Box of 12 Pieces
White EDM mould polishing stones SZ-N series with soft hardness for precision surface finishing.
With our stone options featuring different hardness levels and a wide grit range, we provide professional solutions at every stage, from coarse material removal to the most precise polishing.
EDM Yüzey Geliştirme, EDM Polishing Stones, Gaz Taşı