

💎 Elevate your craft with precision polish and pro-level power!
The Deruilong 4” Flat Grinding Machine is a compact, versatile tool designed for grinding, shaping, and polishing a wide range of gemstones and minerals. Powered by a safe 9V DC supply with overload protection, it features an automatic water cooling system to enhance performance and durability. Lightweight and portable, it includes a comprehensive accessory kit ideal for both beginners and professionals in jewelry making.











| Brand | Deruilong |
| Color | Purple |
| Included Components | entire set |
| Material | Acrylonitrile Butadiene Styrene (ABS) |
| Power Source | DC |
| Specific Uses For Product | Jewelry Making |
A**K
Great little machine super easy to use for beginners like me
Great little machine. Really only works for small stones but you can't find anything like this for this kind of price anywhere else. People complain about the arbor size being too small making replacement discs an impossible find. However, if you just click on the company store they sell a replacement and expanded disc set of the correct size for 22 bucks. I ordered one at the same time I ordered the machine. No need to call them on the phone and struggle through the language barrier as some of these other reviews suggest. My only complaint is that I wish it was 6 in. I haven't tried the polishing pad with polishing paste yet. Highly recommended.
R**R
About the arbor size issue
This is a great little machine. Grinds small rocks very well. For those complaining about arbor size, just order a 5/8 to 3/8 adaptor (aka a washer). I use the disk that comes with the machine as a base, then put on the adaptor, then any type of 5/8 wheel you wanna use. I then flip the retaining nut upside down and tighten. I've cut and polished 35 cabs so far and have had great results.
J**E
Good cheap option for flat lap. Or beginner
Great cheap option for flat lap. Works great for my lapidary jewelry. They sell the disc's and bufff pads on their site. I just bought buff pads and punched 3/8holes.... washer for the 5/8 or 1/2 arbor holes I just bought at hardware store. Better than I thought it would be
K**S
Small but mighty. And super convenient. I love it
I love this flat. Its a bit noisy and it didn't come with the 320 grit sand paper discs. But to be fair on the site it didn't say they were included, but the manual shows them being in the accessories. Its very portable and easy to change out the discs, and I really love the convenience of the recycled water feature. I would love to get this same grinder in a 6" too, otherwise I recommend this grinder for smaller stones and its great for beginners. Please view the images on the site as it has clearer instructions and a parts list. It shows the grit paste in USA terms. If this company offers extra discs for sale that would be great too.
S**D
Deruilong wet grinder
Excellent as described and recommend
T**.
Setup is easy.
Works great, easy to use.
D**E
Amazing flat grinder
This is an awesome flat grinder. Parts are hard to find and the blade guard is delicate so be very careful with it but this product is really awesome! The hole size for blades is 3/8” and hard to find but there is a replacement kit you can order through the seller that includes diamond blade sanding pads and replacement polishing pad
M**M
Cost effective option
Much more economical than a lot of lapidary machines. The arbor is 8 mm in diameter and comes with one diamond wheel in 100 grit. I have many wheels with a 5/8" hole. I made an adapter from a stainless steel washer to fit in the hole and used two stainless steel fender washers, drilled to 8 mm, to clamp the wheels. Works great.
Trustpilot
1 day ago
3 weeks ago