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The Right RPM for Your Diamond Tools

Diamond tools are designed around the equipment they are used with. When you don't have the exact type of equipment, it is critical to still apply the correct operating RPM.

Improper RPM usage is one of the most common reasons that diamond tools stop working. Higher RPM leads to less torque, which means a higher risk of the tooling losing traction and spin out. Therefore, it's always safe to check what the optimal RPM is for the tool you are working with.

Grinding Wheels and Blades:

Below 7" in diameter, these tooling (and thus RPM) are designed for angle grinders. Any standard grinders will perform the job just fine. It is very important for both performance and safety reasons to pay attention to the max RPM that these tools can sustain.

Diameter Recommended RPM Max RPM
4" 9,000 15,000
4.5" 8,000 13,300
5" 7,200 12,000
6" 6,000 10,185
7" 5,100 8,730
8" 4,500 7,640
9" 4,000 6,700
10" 3,600 6,100
12" 3,000 5,000
14" 2,500 4,300
16" 2,200 3,750
18" 2,000 3,300
20" 1,800 3,000

Core Bits:

Dry core bits are typically designed to be used with hand-held core drills, while wet core bits are designed for core drill rigs. There is more flexibility with core bits RPM, as equipments like hammer drills and gas-powered drills can work quite well for small diameter bits.

Bit Outer Diameter Dry Core Bits Wet Core Bits
Min RPM Ideal RPM Max RPM Min RPM Ideal RPM Max RPM
1/2" 4775 6364 7960
5/8" 3820 5091 6368
3/4" 3183 5307 4242
7/8" 2728 3636 4549
1" 2300 4775 6000 2387 3182 3980
1-1/8" 2300 4430 6000 2122 2828 3538
1-1/4" 2300 3820 6000 1910 2545 3184
1-3/8" 1736 2314 2895
1-1/2" 1600 3183 5000 1592 2121 2653
1-5/8" 1469 1958 2449
1-3/4" 1600 2728 5000 1364 1818 2274
1-7/8" 1273 1697 2123
2" 1200 2387 5000 1194 1591 1990
2-1/4" 1200 2122 5000 1061 1414 1769
2-1/2" 1200 1910 5000 955 1273 1592
2-3/4" 868 1157 1447
3" 800 1592 5000 796 1061 1327
3-1/4" 735 979 1225
3-1/2" 800 1364 5000 682 909 1137
4" 700 1241 5000 597 795 995
4-1/4" 562 749 937
4-1/2" 700 1103 5000 531 707 884
5" 700 993 3500 477 636 796
5-1/2" 434 579 724
6" 600 828 2500 398 530 663
6-1/4" 382 509 637
6-1/2" 367 490 612
7" 341 455 569
8" 298 398 498
9" 265 354 442
10" 239 318 398

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  • Mack on

    What would be the ideal operating speed for a 6" expanding drum grinder? What about a plastic-hub nickel-rim 60-grit diamond wheel?

  • Freda on

    Definitely worth sharing!
    Diamond Tools Market


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