CNC Machining Stone - The subtlety of CNC Machining with Granite & Marble CNC Machine Toolings

Source: https://toolings.co.za/stone-tooling-granite-marble (toolings.co.za article, published 2023-04-03)

This is the toolings.co.za explainer on how granite and marble differ and why that matters when they are cut on a CNC router. The 2023 article explains the two stones but stops short of practical machine advice, and its two "Our Range" headings have no product list under them. This deepened version (2026-10-21) keeps the full article below and adds what a client actually needs to decide: which stone behaves how on the machine, which AM.CO.ZA bits and routers fit, how AM.CO.ZA's own stone jobs were run, and when a laser or UV printer is the better tool. It carries no prices and no stock: prices come from the Buythis page (cite with #ai) and stock only from AM live stock.

For the full bit range see AM.CO.ZA Now Sells Granite & Marble CNC Machine Tool Bits (all 41 stone bit SKUs), Granite CNC Machine Toolings and Marble CNC Machine Tooling. For general router bit choice see Router Bits.

Quick answer

• Marble is softer and cuts faster. Use the coarse-grit marble bits, rated for a feed of about 0.8 m/min.
• Granite is harder. Use the fine-grit granite bits, rated for about 0.5 m/min, and take lighter passes.
• Every stone bit is rated for 24,000 RPM or more, and stone is always cut wet. The water cools the bit and the stone and washes the slurry away.
• Use a stone router, not a wood router. The AM.CO.ZA stone machines are the four EasyRoute sink-table, water-cooled routers: R-1325W/55, R-1325SW/55, R-2030W/55 and R-2030SW/55.
• Rough first, then finish. Clear the bulk with a larger flat end bit, then finish detail with a small flat end, ball nose or tapered ball nose bit.
• For surface marking only (photos, names, logos on a polished face), a laser or UV printer is often faster than carving. See Laser and UV alternatives below.

Granite and marble on the CNC router

Two more bit groups sit between them. The medium-grit "light gold" flat end bits (TL-MF-S6T12-60 and TL-MF-S12T12-S8-60) are described for marble, granite and other stone at about 0.5 m/min. The tungsten carbide V-bits with a 0.4 mm tip (TL-TV-S6A4-70 and TL-TV-S6A4-90) are for fine lettering and V-grooves in granite, marble, stone and glass.

Which bit for which step

How to read the SKU: after TL- the first letter is the grit (C coarse, F fine, M medium, T tungsten carbide) and the second is the shape (F flat end, B ball nose, T tapered ball nose, V V-profile). S6 is a 6 mm cutter, T12 is a 12 mm grit (cutting) section, B3 is a 3 mm ball tip, the last number is the minimum full length, and a trailing S means a cooling slot that lets water reach the cutting face. Most packs hold 10 bits; the carbide V-bits come in packs of 5. All are consumables, so they carry no warranty (see the Buythis page).

The CNC stone process, step by step

The article lists five steps (CAD file, loading, programming, cutting, finishing). On an AM.CO.ZA stone router they look like this:

1. Design. Make the CAD or vector file. For relief work, 2.5D files (height maps or STL) are enough; the 2026 stone face video notes that many such files can be downloaded free.
2. Load and clamp. The EasyRoute stone routers have a T-slot clamping table inside a sink, loading wheels at the front, and a Z capacity titled "Z-500mm" for thick stone. Clamp the slab flat and level; an uneven rock is first levelled with a flat end bit.
3. Set up water. The sink table catches the water. The 2023 machine tour says the machine has stainless steel side walls, concertina covers to keep water off moving parts, two water chambers and two submersible pumps, so water can be drained or recycled.
4. Program with the right numbers. Use the bit's own ratings: 24,000 RPM or more, about 0.8 m/min feed for coarse marble bits and about 0.5 m/min for fine granite bits. Take shallow steps and increase only after a test cut.
5. Rough, then finish. Remove the bulk with a large flat end bit, then run the finishing pass with a small flat, ball nose or tapered ball nose bit in small steps so the bit never has too much stone to bite into.
6. Finish the stone. Rinse off the slurry, then polish or seal as the stone needs. The article notes marble should be sealed regularly (at least once a year).

What the routers provide

The four EasyRoute stone routers share a 5.5 kW high-torque water-cooled spindle, 380V power, a sink-style water-cooling table, T-slot clamping and the "Z-500mm" sink table. They differ in size and motors:

The 1300 × 2500 mm machines suit vanity tops, memorials and panels; the 2050 × 3050 mm machines take full slabs and kitchen countertops. Servo models are faster and more accurate; the stepper models are the standard option. Collets, Z travel, chiller and site needs are set out on the stone bits page. The R- sink-table routers are the only routers built for stone; standard wood routers have no water management and should not be used for stone.

How AM.CO.ZA's own stone jobs were run

• Cutting 32 mm granite: 32mm Granite Cutting by EasyRoute CNC Stone Router 12mm Tooling 11mm Step Down 800mm/m Feedrate (2023-04-02). The title gives the recipe: a 12 mm tool, 11 mm step down and 800 mm/min feed on the EasyRoute stone router. That feed is the coarse-bit rating; the current fine-grit granite bits go up to 10 mm and are rated 0.5 m/min, so start slower with them.
• Carving a garden rock into a face: Every Rock is a Gem, Carved Stone Face by CNC Stone Router from AM.CO.ZA (2026-05-17). The rock was first levelled with repeated flat passes, then profiled, then finished with a tapered ball nose bit in small visible steps. The video says the carving took roughly 2 days.
• 3D elephant relief in marble: Elephant Engraving on Marble By EasyRoute Stone CNC Router (2026-10-17). A 14 mm bit did the roughing and a 4 mm bit the finishing, where the skin texture appears; the carving ran for 6 days.
• Flat end stone bits at work: Stone Cutter Router Bits From Toolings.co.za! (2026-10-07). A 14 mm flat end bit cut a 5 mm pocket around the edge and lines from 2 mm to 20 mm deep, then a 4 mm flat end bit carved the logo and text, with water flowing throughout.
• Machine tour: Stone Cutting and Engraving CNC Router with Water Cooling Table for Granite, Marble Cutting (2023-03-19) shows the water-cooled table, pumps and loading wheels.

Note: the 14 mm bit in the 2026 videos is larger than any current stone bit SKU in Buythis (the largest is 12 mm). Offer a 10 mm or 12 mm flat end bit for roughing and confirm with sales.

Laser and UV alternatives

Carving removes stone. When a client only wants an image, name or logo on a polished face, these AM.CO.ZA demonstrations show other machines doing it:

• Fibre laser on marble: Engrave Vector File on Marble Stone by LabelMark Fiber Laser Marking Machine with Setting Explained (2023-04-25)
• Photo on marble or granite by laser: Engrave Image on Marble/Granite by Laser, Solution for Stone Texture/Colour/Pattern Difference (2023-09-13)
• UV laser on granite: Laser Engraving Granite on LabelMark-UV 5W Laser Marking Machine (2026-05-11)
• CO2 laser on granite: LC-1390/100: CO2 laser engraving an image on granite (2025-06-24)
• UV flatbed printing on granite: Printing Directly onto Granite with a UV Flatbed Printer (2026-05-25)

Use the stone router for depth (relief, sink cut-outs, deep lettering, profiles) and a laser or UV printer for flat images and fine surface marks.

Notes on the 2023 article

• The two "Our Range" headings (granite and marble toolings) had no list under them on the original page. The ranges are the granite and marble pages, and the tables above.
• The article links to the Buythis CNC router and router bit category pages. When citing a product for a client, link the product page with #ai, for example R-1325W/55.
• The "Safety" point in the article says CNC machines reduce the risk of injury because they handle stone of any size. The machine still needs safe loading of heavy slabs, water kept away from electrics, and normal eye and hearing protection.
• The FAQ says only certain stones can be CNC machined. In practice the bit choice follows hardness: coarse grit for marble and softer stone, fine grit for granite and harder stone.
• The cost comparison (granite usually cheaper than marble) is about the stone itself, not machining. Granite usually takes longer to machine because it is cut slower and is harder on the bits.

FAQ

Can I cut granite with marble bits? Not well. Marble bits are coarse grit and rated for a faster feed. Granite needs the fine-grit TL-F.. bits at about 0.5 m/min.

Can my wood CNC router cut stone? It is not built for it. Stone needs water at the cut and a machine protected from water and slurry. Use an EasyRoute sink-table stone router.

What spindle speed do stone bits need? All AM.CO.ZA stone bits are rated for 24,000 RPM or more.

Why does the bit have a slot? A trailing S in the SKU means a cooling slot, which helps water reach the cutting face and keeps heat down.

Can I see the stone router working? Yes. The videos above show real jobs, and clients can book a test session through sales at AM.CO.ZA, as the 2023 granite video invites.

Where are prices and stock? Prices are on each Buythis page (cite with #ai). Stock comes only from AM live stock. This page has neither.

Read next

• AM.CO.ZA Now Sells Granite & Marble CNC Machine Tool Bits
• Granite CNC Machine Toolings
• Marble CNC Machine Tooling
• Router Bits
• toolings.co.za site page

Original article (2023-04-03)

The original toolings.co.za article is kept below for reference.

• published: 2023-04-03 15:42:10
• modified: 2023-04-03 17:33:38

When it comes to choosing the right material for your countertops or floors, granite and marble are two of the most popular stones used in construction. Both of these natural stones have unique qualities that make them desirable for different applications. However, many people are confused about the differences between granite and marble and the subtleties in CNC machining these stones. In this article, we will explore the key differences between granite and marble and discuss the intricacies of CNC machining them.

Introduction

Granite and marble are both natural stones that have been used in construction for centuries. These stones have unique properties that make them suitable for different applications. Granite is a hard, igneous rock that is composed of quartz, feldspar, and mica. Marble is a metamorphic rock that is formed from limestone under high pressure and heat. Both of these stones have their own strengths and weaknesses that make them suitable for different uses.

What is Granite?

Granite is a natural stone that is formed from magma. It is an igneous rock that is composed of quartz, feldspar, and mica. Granite is one of the hardest and most durable natural stones available. It is resistant to scratches, heat, and stains, which makes it ideal for use in kitchens and bathrooms.

Our Range of CNC Machine Granite Toolings

What is Marble?

Marble is a natural stone that is formed from limestone under high pressure and heat. It is a metamorphic rock that is composed of calcium carbonate. Marble has a unique veining pattern that makes it a popular choice for use in decorative applications. Marble is not as hard as granite and is more porous, which makes it more susceptible to staining.

Our Range of CNC Machine Marbling Toolings

Differences between Granite and Marble

Granite and marble are both natural stones, but they have several key differences that make them suitable for different applications. Here are some of the main differences between granite and marble:

• Strength and DurabilityGranite is one of the hardest natural stones available. It is resistant to scratches, heat, and stains, which makes it ideal for use in kitchens and bathrooms. Marble, on the other hand, is not as hard as granite and is more susceptible to scratching and staining. Making the need for the correct cutting and shaping toolings of vital importance - see our range of Marble and Granite CNC Machine Toolings for cost-effective performance.

• AppearanceGranite and marble have very different appearances. Granite has a more uniform appearance and is available in a wider range of colours. Marble, on the other hand, has a unique veining pattern that makes it a popular choice for use in decorative applications.

• Porosity and StainingGranite is less porous than marble, which makes it more resistant to staining. Marble is more porous, which makes it more susceptible to staining. This means that granite is a better choice for use in high-traffic areas like kitchens and bathrooms.

• MaintenanceBoth granite and marble require regular maintenance to keep them looking their best. However, marble requires more maintenance than granite. Marble needs to be sealed regularly to protect it from staining, while granite does not.

• CostGranite is generally less expensive than marble. However, the cost of granite and marble can vary depending on factors such as the quality of the stone, the location of the quarry, and the availability of the stone.

CNC Machining Stones like Granite and Marble CNC Machining Process

CNC (Computer Numerical Control) machining is a process that uses computer-controlled machines to cut and shape materials. This process is widely used in the construction industry to create precise and intricate shapes from natural stones like granite and marble. The CNC machining process involves the following steps:

• Designing the CAD file: A CAD (Computer-Aided Design) file is created using software that is specifically designed for CNC machining. This file contains the design that will be machined into the stone.

• Loading the stone: The stone is loaded onto the CNC machine and secured in place.

• Programming the machine: The CAD file is loaded into the CNC machine and the machine is programmed to cut and shape the stone according to the design.

• Cutting the stone: The machine cuts the stone using a variety of cutting tools likeCNC Routers equipped with specialist toolings and bits.

• Finishing the stone: Once the stone has been cut, it is finished using a variety of techniques, including polishing and sanding.

Advantages of CNC Machining

CNC machining has several advantages over traditional methods of stone cutting and shaping. These advantages include:

• Precision: CNC machines are able to cut and shape stone with a very high degree of precision, which makes it possible to create intricate designs and shapes.

• Efficiency: CNC machines are able to work quickly and efficiently, which reduces the time and cost associated with stone cutting and shaping.

• Consistency: CNC machines are able to produce consistent results, which ensures that each piece of stone is identical to the next.

• Safety: CNC machines are able to work with stones of all sizes and shapes, which reduces the risk of injury to workers.

CNC Machining Granite and Marble

CNC machining is a popular method for cutting and shaping natural stones like granite and marble. This process allows for the creation of intricate and precise designs that would be difficult to achieve using traditional methods. CNC machining is particularly useful for creating custom countertops, flooring, and other decorative features.

When CNC machining granite and marble, it is important to use the correct cutting tools and techniques to ensure that the stone is not damaged during the machining process. It is also important to consider the porosity and density of the stone, as this can affect the machining process and the final result.

Conclusion

In conclusion, granite and marble are two popular natural stones that have unique properties that make them suitable for different applications. CNC machining is a process that is widely used in the construction industry to cut and shape natural stones like granite and marble. While CNC machining has several advantages over traditional methods of stone cutting and shaping, it also has some challenges that must be addressed. When CNC machining granite and marble, it is important to use the correct cutting tools and techniques to ensure that the stone is not damaged during the machining process.

FAQs

• Is granite more durable than marble?

• Yes, granite is generally considered to be more durable than marble.

• What is the cost difference between granite and marble?

• Granite is generally less expensive than marble, although the cost can vary depending on factors such as the quality of the stone.

• Can any type of stone be CNC machined?

• No, only certain types of stones can be CNC machined. The stone must be hard enough to withstand the cutting process and must also be able to be polished to a smooth finish.

• How often does marble need to be sealed?

• Marble should be sealed at least once a year to protect it from staining.

• Is CNC machining safe for workers?

• Yes, CNC machines are able to work with stones of all sizes and shapes, which reduces the risk of injury to workers. However, it is important for workers to follow proper safety procedures when working with these machines.