Convert torque between N·m, lb·ft, lb·in, kgf·m and ozf·in. Enter one value to see all the others — for tapping torque specs, torque wrenches and machine ratings quoted in different units.
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Request a Proposal →Published starting values are not measurements. They are recommendations, and they differ because each manufacturer optimises for something different — tool life, surface finish, chip control, or spindle power. Two suppliers can quote the same ISO grade and give you cutting speeds 30% apart, and each figure can be right for that supplier’s own geometry, edge preparation and coating.
That is why the number this calculator returns is a starting point, not a setting. Treat the catalogue figure as the middle of a band, then correct it on the first part: if the chips come off blue or the spindle load sits above roughly 80%, come down; if the finish is smeared and the chips are thin and stringy, come up. Write down what actually worked — that shop-specific number beats any published value.
Torque appears throughout machining -- spindle motor torque, bolt tightening specs, tool holder clamping nuts, and workholding forces. Different manufacturers use different units; this converter handles them all.
A typical 40-taper VMC spindle produces 50-150 Nm (37-110 lb-ft) at low RPM. For face milling steel with a 63 mm cutter at 2 mm depth, you need about 30-50 Nm at the spindle. Check your machine torque curve -- torque typically drops above 1500-3000 RPM as the motor transitions to constant-power mode.
ER16: 40-50 Nm (30-37 lb-ft). ER25: 70-90 Nm (52-66 lb-ft). ER32: 100-130 Nm (74-96 lb-ft). ER40: 130-170 Nm (96-125 lb-ft). Use a torque wrench -- under-tightening causes tool slippage; over-tightening damages the collet and nut and reduces runout accuracy.
1 ozf-in = 0.00706 Nm. For example, 50 ozf-in (common for M3-M4 screws) = 0.35 Nm. Small torque values are easier to read in ozf-in or Ncm (Newton-centimetre). 1 Ncm = 0.01 Nm = 1.416 ozf-in. Use a calibrated torque screwdriver for fasteners under 5 Nm.
Enter a torque value in any supported unit. The converter shows equivalents in Nm, lb-ft, lb-in, kgfm, and ozf-in. Use this to compare spindle specifications, bolt torque charts, and tool holder clamping specs across manufacturers using different unit systems.
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Use the calculator freely. If the result points to a tooling or process problem, we can source the exact carbide tooling you need from vetted factories in China. Compare factory-direct pricing.
Before you commit to a spec, it helps to know what the market pays for it. These are real, publicly listed factory prices — not a quotation, and not a guess.
We source the tool families below direct from vetted Chinese factories, matched to the material and tolerance you just worked out. Every batch ships with its material certificate and dimensional record.
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CONVERTING TORQUE UNITS? Tapping torque is a purchase specification, not just a setup number. See what a tap inquiry needs to include.
We source carbide cutting tools from China for job shops. We do not own a factory, which is why we can quote your drawing against two or three plants that actually run your material.
Cutting formulas with the units worked through · Speed and feed starting points for all six ISO material groups · How to read a carbide grade past its ISO code. 12 pages.
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