(M18) Hex Head Cap Screws, Fully Threaded, Grade C are manufactured to ISO 4018 with a coarse thread pitch of the standard value. This page lists the controlling dimensions for the (M18) size — head geometry, width across flats, matching spanner size — together with the clearance hole, tapping drill and tightening torque used at assembly.
(M18) 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| (M18) | 2.5 | 7.5 | 2.5 | 0.8 | 21.2 | 24.85 | 29.56 | 11.5 | 12.4 | 10.6 | 7.42 | 0.6 | 27 | 26.16 | 35~180 | ISO 4018 |
Spanner & Drive for (M18) Hex Head Cap Screws, Fully Threaded, Grade C
(M18) Hex Head Cap Screws, Fully Threaded, Grade C have a width across flats of 27 mm — fit a 27 mm open-ended spanner or socket. In tight access a 6-point socket on the 27 mm flats gives the most engagement per degree of swing. Where the joint is torqued to a figure, a click wrench is the only way to reproduce it across a batch.
(M18) Hex Head Cap Screws, Fully Threaded, Grade C Weight
A steel (M18) hex head cap screws, fully threaded, grade c at the listed 35,180 mm length weighs approximately 70,332 g each — about 70,332 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 (M18) 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.
- Serrated flanges need to sit directly on the joint face. A washer between the two removes the bite and leaves an ordinary bolted joint that is believed to be a locking one.
- At (M18) 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 (M18)
For (M18), pair with a (M18) hex nut (ISO 4032 / DIN 934) and, where used, a (M18) 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 (M18) 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.
