ENGINEERING TOOL
M36 Bolt Torque Chart: Specs, Values & Settings
Class 8.8 · Target preload (kN) 366
| Dry / Black | 2635 N·m 2372–2899 |
| Electro Zinc | 2240 N·m 1976–2635 |
| Hot-Dip Galv. | 2899 N·m 2372–3294 |
| Oiled | 1713 N·m 1581–1976 |
M36 bolt torque spec: class 8.8 dry is 2635 N·m (1943 ft·lb). Values cover six property classes across five friction states — dry, zinc, HDG, oiled and anti-seize. K-factor method, basis fully disclosed.
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Torque by Property Class and Friction State
Quick answer: class 8.8 · dry / black ≈ 2635 N·m (2372–2899); other classes and friction states below.
| Class | Rp0.2 (MPa) | Target preload (kN) | Dry / Black K 0.18–0.22 · N·m | Electro Zinc K 0.15–0.2 · N·m | Hot-Dip Galv. K 0.18–0.25 · N·m | Oiled K 0.12–0.15 · N·m | Wax / PTFE / Anti-seize K 0.08–0.12 · N·m |
|---|---|---|---|---|---|---|---|
| 4.8 | 340 | 194.4 | 1400 1260–1540 | 1190 1050–1400 | 1540 1260–1750 | 910 840–1050 | 700 560–840 |
| 8.8 | 640 | 366 | 2635 2372–2899 | 2240 1976–2635 | 2899 2372–3294 | 1713 1581–1976 | 1318 1054–1581 |
| 10.9 | 940 | 537.6 | 3871 3484–4258 | 3290 2903–3871 | 4258 3484–4838 | 2516 2322–2903 | 1935 1548–2322 |
| 12.9 | 1100 | 629.1 | 4529 4077–4982 | 3850 3397–4529 | 4982 4077–5662 | 2944 2718–3397 | 2265 1812–2718 |
| A2-70 | 450 | 257.4 | 1853 1668–2038 | 1575 1390–1853 | 2038 1668–2316 | 1204 1112–1390 | 926 741–1112 |
| A4-80 | 600 | 343.1 | 2471 2224–2718 | 2100 1853–2471 | 2718 2224–3088 | 1606 1482–1853 | 1235 988–1482 |
Cell shows the typical value; the small line below is the range (min–max).
References
- ISO 898-1:2013 — Mechanical properties of fasteners made of carbon and alloy steel
- ISO 3506-1:2020 — Mechanical properties of corrosion-resistant stainless steel fasteners (A2/A4)
- GB/T 3098.1-2010 — Mechanical properties of bolts, screws and studs (CN national standard, official full text)
- GB/T 3098.6-2014 — Mechanical properties of stainless steel bolts, screws and studs (CN, official full text)
- ISO 16047:2005 — Fasteners: torque/clamp force testing (K-factor measurement method)
- Machinery's Handbook (30th ed.) — empirical K-factor ranges
- Machine Design — anti-seize compound friction test (K≈0.10)
Fine-Thread Torque Matrix
Fine-thread series (M36 × 3 mm) target preload and tightening torque ranges, same basis as the coarse chart; the fine-thread stress area As follows ISO 898-1:2013 Table 6 (this page takes M36 As = 865 mm²).
| Class | Rp0.2 (MPa) | Target preload (kN) | Dry / Black K 0.18–0.22 · N·m | Electro Zinc K 0.15–0.2 · N·m | Hot-Dip Galv. K 0.18–0.25 · N·m | Oiled K 0.12–0.15 · N·m | Wax / PTFE / Anti-seize K 0.08–0.12 · N·m |
|---|---|---|---|---|---|---|---|
| 4.8 | 340 | 205.9 | 1482 1334–1630 | 1260 1112–1482 | 1630 1334–1853 | 963 889–1112 | 741 593–889 |
| 8.8 | 640 | 387.5 | 2790 2511–3069 | 2372 2093–2790 | 3069 2511–3488 | 1814 1674–2093 | 1395 1116–1674 |
| 10.9 | 940 | 569.2 | 4098 3688–4508 | 3483 3074–4098 | 4508 3688–5123 | 2664 2459–3074 | 2049 1639–2459 |
| 12.9 | 1100 | 666.1 | 4796 4316–5275 | 4076 3597–4796 | 5275 4316–5994 | 3117 2877–3597 | 2398 1918–2877 |
| A2-70 | 450 | 272.5 | 1962 1766–2158 | 1668 1471–1962 | 2158 1766–2452 | 1275 1177–1471 | 981 785–1177 |
| A4-80 | 600 | 363.3 | 2616 2354–2877 | 2223 1962–2616 | 2877 2354–3270 | 1700 1569–1962 | 1308 1046–1569 |
Cell shows the typical value; the small line below is the range (min–max).
Basis of Calculation & Sources
Calculation basis
- Torque follows the K-factor (nut factor) method T = K·D·F: D is the nominal diameter and F the target preload = 70% of Rp0.2 × thread stress area (M36 As = 817 mm²).
- Yield strengths are published values from ISO 898-1 (carbon/alloy steel) and ISO 3506-1 (stainless A2/A4).
- K follows published empirical ranges per friction condition (Machinery's Handbook; the wax/PTFE/anti-seize band K≈0.10 follows Machine Design test data).
- The grease/MoS₂ band (K≈0.11) nearly overlaps anti-seize and is available in the calculator instead of a separate column.
Stainless note: A2/A4 austenitic thread pairs gall easily under frictional heating. Always apply anti-seize and follow the Wax/PTFE/Anti-seize column (K≈0.10).
Scope & limits
- This chart is a simplified K-factor estimate, not a full VDI 2230 analysis (which accounts for joint resilience, embedment and assembly method).
- Friction is the dominant variable — no single torque value exists without its friction state.
- Always follow the design specification or manufacturer torque table.
Cite this chart
YAXIIO. M36 Bolt Torque Chart: Specs, Values & Settings. https://www.yaxiio.com/en/tools/bolt-torque-chart/m36 (accessed 2026-10-29).
Free to cite and embed — attribution required: “YAXIIO” + a link to this page.
FAQ
What is the target preload for an M36 bolt?
At 70% of Rp0.2: class 4.8 ≈ 194.4 kN, 8.8 ≈ 366 kN, 10.9 ≈ 537.6 kN; stainless A2-70 ≈ 257.4 kN and A4-80 ≈ 343.1 kN.
Can I use carbon-steel torque values for stainless M36 (A2-70/A4-80)?
No. The classes have different yield strengths (A2-70 = 450 MPa, A4-80 = 600 MPa), so target preloads differ; and stainless thread pairs gall easily — always apply anti-seize and follow the Wax/PTFE/Anti-seize column (K≈0.10).
Next: work out your order, or pick the size by standard
Related References
Bolt Torque Calculator
Interactive version: fine threads, imperial, stud bolts, custom K and torque check — this size is pre-filled.
M36 Hex Bolt Weight Chart
Per-piece and per-1,000-pcs weights across the full length series of the same size.
Tap Drill for the Thread Being Tightened
The hole under the bolt: rule tap drill value plus the nearest drill bit in the set, stated ahead of the torque tables.
Disclaimer: This chart is an engineering estimation for selection and budgeting only. It does not constitute assembly instructions or acceptance criteria.