M64 Hex Head Cap Screws, Fully Threaded, Grade C (ISO 4018) are specified by thread size, length and head dimensions. The M64 row from the standard is reproduced below, followed by the drill sizes, spanner size and torque values used when installing this size.
M64 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M64 | 6 | 18 | 6 | 1 | 75 | 88.16 | 104.86 | 40 | 41.25 | 38.75 | 27.13 | 2 | 95 | 92.8 | 120~500 | ISO 4018 |
Spanner & Drive for M64 Hex Head Cap Screws, Fully Threaded, Grade C
M64 Hex Head Cap Screws, Fully Threaded, Grade C have a width across flats of 95 mm — fit a 95 mm open-ended spanner or socket. A 6-point socket grips all six flats of the 95 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 M64
| Coarse-thread pitch (ISO 724) | 6 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 70 mm |
| Tapping drill, coarse thread | 58 mm |
Tightening Torque for M64
| Class 8.8 (dry, ~µ 0.125) | ≈ Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 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 M64
| Tensile stress area As (ISO 724) | 2676 mm² |
|---|
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.
M64 Hex Head Cap Screws, Fully Threaded, Grade C Weight
A steel M64 hex head cap screws, fully threaded, grade c at the listed 120,500 mm length weighs approximately 3,045,486 g each — about 3,045,486 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 M64 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 M64 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 M64
For M64, pair with a M64 hex nut (ISO 4032 / DIN 934) and, where used, a M64 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 M64 hex head cap screws, fully threaded, grade c. Thread size and pitch, length, property class, drive form, head geometry and head marking are all specifiable — the standard part is where it starts, not where it stops. Made by cold heading or hot forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
