Mike Reeves, ASE Master Technician · Last reviewed June 4, 2026

Metric Bolt Torque Chart

The full coarse-thread chart — M6 through M24 in Class 8.8, 10.9, and 12.9. Unlike the static PDFs everywhere else, this one recomputes live when you switch between dry, oiled, and anti-seize, and flips between N·m and ft-lb in one tap. Tap any cell to pin the full spec.

Metric Bolt Torque Chart

Metric coarse-thread bolt tightening torque by size and grade
Size × pitch Class 8.8 Class 10.9 Class 12.9
M6 × 1.0 — — —
M8 × 1.25 — — —
M10 × 1.5 — — —
M12 × 1.75 — — —
M14 × 2.0 — — —
M16 × 2.0 — — —
M18 × 2.5 — — —
M20 × 2.5 — — —
M22 × 2.5 — — —
M24 × 3.0 — — —

Tap any cell to pin its full spec below. Values are N·m, coarse-thread, at the selected condition. Real-world torque wrenches are ±25% accurate — verify against OEM service data for a specific joint.

Recommended torque
General-purpose
Nm
88
ft-lb
65
in-lb
779

M12 × 1.75 Class 8.8 dry: tighten to ~88 Nm (65 ft-lb). Use a 3/8" drive torque wrench. Allow ±25% wrench accuracy — verify against OEM service data.

3/8" drive (15–80 ft-lb) — engine accessories, brackets

OEM spec overrides — verify your joint in the service manual.

Mike's pick for hitting this spec

Reference values, not safety-of-life data. Computed with the industry T = K × D × F formula using F = 75% of proof load (ISO 898-1 proof stresses, ISO 724 coarse-thread tensile-stress areas). Torque wrenches are ±25% accurate at best. These are maximum tightening values for clean, coarse-thread fasteners — always verify against the OEM service data for your specific joint, and never apply a "dry" spec to a lubricated bolt. Mike Reeves is an ASE Master Technician, not your dealership service writer.

Embed this chart on your site for free

How to use this chart

  1. Find your bolt size. Measure the thread diameter, not the head or the wrench — an M12 bolt has a 12 mm thread, regardless of whether it takes a 17 mm or 19 mm socket. The size column also lists the standard coarse pitch (M12 × 1.75).
  2. Find the grade. It's stamped on the bolt head: 8.8, 10.9, or 12.9. Higher number, stronger bolt, higher torque. If the head is blank or you can't read it, assume 8.8 (the weakest of the three) so you don't over-torque.
  3. Set the thread condition. This is the part most charts get wrong by ignoring it. A dry bolt and an anti-seized bolt at the same size and grade need very different torque — the chart recomputes the whole table the instant you change it.
  4. Read the cell — or tap it. The number where your size row meets your grade column is the max tightening torque. Tap the cell to pin it: you'll get N·m, ft-lb, and in-lb at once, the wrench class you need, and a plain-English summary.
  5. Switch units if you need to. Got a ft-lb-only torque wrench but a manual that specs N·m? One tap flips the entire chart.
  6. Save it. "PDF chart" downloads the entire chart for your chosen condition — keep it in the toolbox. "Share" copies a link with your exact cell preserved.

Why this chart is different from the PDFs in search results

Search for a metric bolt torque chart and you get a wall of static PDFs from fastener suppliers — Fastener Mart, Fastenal, Martin Supply, Grampian — plus a couple of engineering blogs. Every one of them is a fixed image: one condition, one set of units, printed once and never touched again. Here's what we did differently:

  • Live condition recompute. Switch between dry, zinc-plated, lightly oiled, and anti-seize and every value in the table changes. A static PDF picks one assumption (usually "dry, lightly oiled at 85% proof") and hides it in a footnote — which is exactly how people over-torque an anti-seized bolt by nearly 2×.
  • One-tap unit flip. N·m ↔ ft-lb for the whole chart. The PDFs make you find a separate ft-lb chart or do the conversion in your head on a greasy phone.
  • Tap-to-pin spec card. Tap any cell and get N·m, ft-lb, and in-lb together, plus the wrench drive size you actually need. No squinting at a 10 × 3 grid to find one number.
  • Regenerating PDF. The download isn't a fixed image — it's your chart, built for the condition and reviewed by an ASE Master Tech, with the K-factor key printed on it.
  • Embeddable. None of the top organic results offer an embed. Trailer-build threads, restoration forums, and shop blogs can drop this chart in with one line of HTML — attribution intact.
  • Mechanic-flavored, not industrial. Mike Reeves (ASE Master Tech) signs the math, and the result card tells you the wrench drive size — "3/8" drive, engine accessories" — instead of just spitting a number.

How the numbers are calculated

Bolt torque is mostly about friction, not the bolt. Roughly 85–90% of the torque you apply fights friction in the threads and under the head; only the rest becomes useful clamping force. That's why the standard formula used by every authoritative reference (Engineering Toolbox, Fractory, Fastenal) is:

T = K × D × F

  • T — tightening torque
  • K — the nut factor / friction coefficient (this is what "thread condition" sets)
  • D — nominal bolt diameter (6 mm for M6, and so on)
  • F — target clamp force, set to 75% of the bolt's proof load by industry convention

Proof load comes from the grade: the proof stress (580 MPa for Class 8.8, 830 MPa for 10.9, 970 MPa for 12.9, per ISO 898-1) multiplied by the thread's tensile-stress area (per ISO 724 for coarse pitch). Take 75% of that, multiply by K and the diameter, and you have the torque. This is the same engine behind our bolt torque calculator — verified against a fixture-test suite that ships next to the chart's source code.

K-factor: why thread condition matters so much

K is friction. Drop it and the same bolt needs less torque to reach the same clamp force:

  • Dry / plain steel — K = 0.20. The default on most published charts.
  • Zinc-plated — K = 0.20. Friction is about the same as dry plain steel.
  • Lightly oiled — K = 0.18. A wipe of oil or assembly lube; about 10% less torque.
  • Anti-seize / heavy lube — K = 0.10. Cuts the required torque roughly in half.

If a manual says "90 N·m dry" and you put anti-seize on the threads, applying 90 N·m now over-stretches the bolt by nearly double the intended preload — which is how aluminum threads strip and head bolts snap. Match the condition to what's actually on the bolt.

Why the result is approximate (the ±25% problem)

Per Fastenal's own engineering note and SAE convention, even a perfect input torque varies the resulting preload by as much as ±25% — real K-factors drift with rust, dirt, hole misalignment, and torque-wrench calibration. This chart gives you the right starting value, not a substitute for an OEM spec when one exists. On torque-to-yield bolts (single-use stretch fasteners, common on modern head bolts and rod bolts), ignore any chart and follow the angle-torque procedure in the service manual.

Common metric bolt torque values (dry, Class 8.8)

  • M6 × 1.0 — 10.5 N·m (7.7 ft-lb). Small covers, sensors, plastic trim brackets. A 1/4" drive or in-lb wrench — easy to snap an M6 with a big ratchet.
  • M8 × 1.25 — 25.5 N·m (18.8 ft-lb). Valve covers, splash shields, small brackets. 3/8" drive.
  • M10 × 1.5 — 50.5 N·m (37 ft-lb). The everyday automotive bolt — intake manifolds, accessory brackets, suspension links. 3/8" drive.
  • M12 × 1.75 — 88 N·m (65 ft-lb). Bigger suspension and chassis bolts. Move up to a 1/2" drive.
  • M14 × 2.0 — 140 N·m (103 ft-lb). Subframe, control-arm, and ball-joint hardware. 1/2" drive.
  • M16 × 2.0 — 219 N·m (161 ft-lb). Heavy chassis and axle bolts. 1/2" long-handle or 3/4" drive.

Jump a grade and the numbers climb fast: M12 in Class 10.9 is 126 N·m, and in 12.9 it's 147 N·m — same bolt size, very different spec. That's why reading the head stamp matters.

Frequently asked questions

What is the torque for an M10 bolt?

For a Class 8.8 M10 × 1.5 coarse-thread bolt, dry, the maximum tightening torque is about 50 N·m (37 ft-lb). In Class 10.9 it rises to ~72 N·m (53 ft-lb), and in 12.9 to ~84 N·m (62 ft-lb). Lubricated, drop those by roughly 10%; anti-seized, roughly halve them. Always defer to an OEM spec for the specific joint.

How much torque for a Class 10.9 vs 12.9 bolt?

Class 10.9 uses a proof stress of 830 MPa and 12.9 uses 970 MPa, so 12.9 takes about 17% more torque than 10.9 at the same size and condition. For example, an M12 × 1.75 dry bolt is ~126 N·m in 10.9 and ~147 N·m in 12.9. Set the grade column and condition on the chart to see exact values.

Do I reduce torque for a lubricated bolt?

Yes — and it's a bigger reduction than most people expect. Light oil drops the friction factor from K=0.20 to about 0.18 (roughly 10% less torque); anti-seize drops it to about K=0.10, which means nearly half the dry torque for the same clamp force. Set the "Thread condition" control to match what's on the bolt before reading the value. Applying a dry spec to a greased bolt is a classic way to strip threads.

What does coarse thread mean, and does this chart cover fine thread?

Coarse thread is the standard pitch for a given diameter (M10 × 1.5, M12 × 1.75) and is what you'll find on the vast majority of automotive and general fasteners. This chart uses coarse-thread tensile-stress areas. Fine-thread bolts (e.g., M12 × 1.25) have a slightly larger stress area and tolerate a little more torque — if you're working with fine thread, treat these values as a conservative floor and consult the manufacturer's table.

Is a higher-grade bolt always better?

Not always. Higher-grade bolts (12.9) are stronger but more brittle and less forgiving of shock loads — many chassis and suspension applications deliberately spec 8.8 or 10.9 for ductility. Never substitute a higher or lower grade than the OEM calls for, and torque to the grade you actually have, not the grade you wish you had.

A torque chart only matters if you have a wrench that can hit the number accurately:

  • Best Torque Wrenches — a click-style 1/2" drive (30–250 ft-lb) covers suspension, brakes, and most engine bolts; add a 3/8" drive (15–80 ft-lb) for small fasteners and an in-lb wrench for M6/M8 work. Never trust an impact gun for a final torque pass.
  • Best Mechanic Tool Sets — a 3/8" drive set with deep metric sockets is the daily-driver of bolt work; the torque wrench rides on a ratchet handle, not on its own.
  • Best Impact Wrenches — to break loose stuck or over-torqued bolts and snug them back, then finish at spec with the click wrench.

Sources & methodology

The chart-cell values this tool is tested against are in fixtures.json alongside the component source, with a fixtures.test.mjs suite asserting the formula, grade/size monotonicity, K-factor ratios, and severity gates. About Mike Reeves · Last reviewed June 4, 2026.

Embed this chart on your site

Free for restoration and build threads, trailer and truck forums, motorcycle wrenching stickies, vocational instructors, and shop blogs. Required attribution is included in the snippet — no fee, no signup, no analytics attached to the embed. 

<iframe
  src="https://revrated.com/metric-bolt-torque-chart/embed/"
  width="100%"
  height="760"
  loading="lazy"
  style="border:1px solid #d8dbe5; border-radius:16px; max-width:760px;"
  title="Metric Bolt Torque Chart (RevRated)">
</iframe>
<p style="font-size:12px;color:#666;margin-top:8px">
  Metric bolt torque chart by
  <a href="https://revrated.com/metric-bolt-torque-chart/">RevRated</a>
  &middot; Reviewed by Mike Reeves, ASE Master Technician
</p>