M16 Torx Recessed Countersunk Screw are manufactured to GB/T 2673 / ISO 14587 with a coarse thread pitch of 2 mm. This page lists the controlling dimensions for the M16 size — head geometry, width across flats, matching spanner size — together with the clearance hole, tapping drill and tightening torque used at assembly.
M16 Dimensional Row (GB/T 2673 / ISO 14587)
| Size | Pitch (mm) | Length L (mm) | Head diameter dk (mm) | Head height k (mm) | Cross recess | Countersink angle (deg) | Reference standard |
|---|---|---|---|---|---|---|---|
| M16 | 2.0 | 100 | 29.0 | 8.0 | PH4 | 90 | ISO 7046 / GB/T 819 |
Spanner & Drive for M16 Torx Recessed Countersunk Screw — GB/T 2673 / ISO 14587 (Series 024)
The hex socket for M16 Torx Recessed Countersunk Screw — GB/T 2673 / ISO 14587 (Series 024) is shown in the spec table — use the matching Allen / hex key (an ISO 2936 hex key set covers the full range). A T-handle Allen key gives the best feel for setting preload by feel; for production work use a torque-controlled driver.
Hole Sizes for M16
| Coarse-thread pitch (ISO 724) | 2 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 17.5 mm |
| Tapping drill, coarse thread | 14 mm |
Tightening Torque for M16
| Class 8.8 (dry, ~µ 0.125) | ≈ 210 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 295 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 355 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 M16
| Tensile stress area As (ISO 898-1) | 157 mm² |
|---|---|
| Proof load, class 8.8 | 91 kN |
| Proof load, class 10.9 | 130 kN |
| Proof load, class 12.9 | 152 kN |
| Min. ultimate tensile, class 8.8 | 126 kN |
Proof load = stress area × proof stress per ISO 898-1. Design joints so the working preload stays below the proof load of the selected class.
M16 Torx Recessed Countersunk Screw — GB/T 2673 / ISO 14587 (Series 024) Weight
A steel M16 torx recessed countersunk screw at the listed 100 mm length weighs approximately 519 g each — about 519 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.
Common Applications for M16 Torx Recessed Countersunk Screw — GB/T 2673 / ISO 14587 (Series 024)
M16 Torx Recessed Countersunk Screw — GB/T 2673 / ISO 14587 (Series 024) are commonly specified for heavier machine assembly and equipment mounting.
Mating Parts for M16
For M16, pair with a M16 hex nut (ISO 4032 / DIN 934) and, where used, a M16 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
When to Step Up or Down from M16
When the joint preload approaches the proof load of M16 class 8.8, step up to M20 class 8.8 (or move to M16 class 10.9). When the joint is over-specified, M12 often saves weight and cost without losing the safety margin.