This page covers M36 Hex Head Cap Screws, Fully Threaded, Grade C to ISO 4018: the full dimensional row, hole and tool sizes, proof-load data and typical applications. All values are taken from the governing standards (ISO 4018 together with ISO 273, ISO 724 and ISO 898-1 where applicable).
M36 Dimensional Row (ISO 4018)
| Size | Pitch P (mm) | a_max (mm) | a_min (mm) | c_max (mm) | d_a_max (mm) | d_w_min (mm) | Width across corners e (mm) | Head height k (mm) | k_max (mm) | k_min (mm) | k_w_min (mm) | r_min (mm) | Width across flats s (mm) | s_min (mm) | Length range l (mm) | Reference standard |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M36 | 4 | 12 | 4 | 0.8 | 42.4 | 51.11 | 60.79 | 22.5 | 23.55 | 21.45 | 15.02 | 1 | 55 | 53.8 | 70~360 | ISO 4018 |
Spanner & Drive for M36 Hex Head Cap Screws, Fully Threaded, Grade C
M36 Hex Head Cap Screws, Fully Threaded, Grade C have a width across flats of 55 mm — fit a 55 mm open-ended spanner or socket. A 6-point socket grips all six flats of the 55 mm hex and is what to reach for once a fastener has been on and off a few times; a 12-point ring spanner starts rounding a worn head. For repeatable preload, torque rather than feel.
Hole Sizes for M36
| Coarse-thread pitch (ISO 724) | 4 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 39 mm |
| Tapping drill, coarse thread | 32 mm |
Tightening Torque for M36
| Class 8.8 (dry, ~µ 0.125) | ≈ 2523 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 3593 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 4204 Nm |
Indicative dry-joint values. Lubrication can lower the required torque by 15–25%. Always confirm against the joint design, especially when going up a strength class.
Proof Load & Strength for M36
| Tensile stress area As (ISO 724) | 817 mm² |
|---|---|
| Proof load, class 8.8 | 490 kN |
| Proof load, class 10.9 | 678 kN |
| Proof load, class 12.9 | 792 kN |
| Min. ultimate tensile load, class 8.8 | 678 kN |
Proof load = tensile stress area × the proof stress Sp of the class, per ISO 898-1 — Sp is a lower figure than the yield stress Rp0.2 and the two are not interchangeable. The stress area is computed from this size's own diameter and pitch, so a fine-pitch designation gives the fine-pitch figure. Design the joint so the working preload stays below the proof load of the class selected.
M36 Hex Head Cap Screws, Fully Threaded, Grade C Weight
A steel M36 hex head cap screws, fully threaded, grade c at the listed 70,360 mm length weighs approximately 562,662 g each — about 562,662 kg per 1,000 pieces. Stainless A2/A4 weighs roughly the same (density 7.9–8.0 g/cm³).
Actual weight varies slightly with head form, thread and finish; use this figure for freight estimation only.
Installation Tips for M36 Hex Head Cap Screws, Fully Threaded, Grade C
- Use a 6-point socket where access allows — 12-point sockets are more prone to rounding the corners on smaller sizes.
- On flanged or serrated variants, do NOT add a separate flat washer — the flange already spreads the load and the washer can defeat the locking serrations.
- At M36 the stretch in the bolt becomes the controlling factor — for critical joints, use angle-controlled or stretch-controlled tightening instead of pure torque.
Mating Parts for M36
For M36, pair with a M36 hex nut (ISO 4032 / DIN 934) and, where used, a M36 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
Custom manufacturing · Made to drawing
Need hex head cap screws, fully threaded, grade c in a size this table does not list?
This page covers M36 hex head cap screws, fully threaded, grade c. Lengths and thread lengths outside the standard table are the commonest request, followed by a drive the standard does not offer and a head marked with your own part number. Made by cold heading or hot forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

