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Screw
Headside
Pointside (timber)
Predrilling required (EC5 §10.4.5(1)): lead hole = shank diameter over the shank length; ≈70% of shank diameter over the threaded portion.
Timber–timber, single shear (screw)
Johansen Yield Modes
| Mode | EC5 ref | Raw (N) | +Rope (N) | Fv,Rk (N) |
|---|---|---|---|---|
| a | EC5 Table 8.2 (a) | 6459.1 | — | 6459.1 |
| b | EC5 Table 8.2 (b) | 10765.1 | — | 10765.1 |
| c ◄ | EC5 Table 8.2 (c) | 3756.1 | — | 3756.1 |
| d | EC5 Table 8.2 (d) | 2568.0 | 1942.2 | 4510.2 |
| e | EC5 Table 8.2 (e) | 3956.1 | 1942.2 | 5898.3 |
| f | EC5 Table 8.2 (f) | 2273.8 | 1942.2 | 4216.0 |
EC5 Minimum Spacings — Table 8.4 (bolt rules)
Timber (headside) — α = 0°
| Spacing parallel to grain (a1) | 26.4 mm |
| Spacing perpendicular to grain (a2) | 21.1 mm |
| Loaded end distance (a3,t) | 80.0 mm |
| Unloaded end distance (a3,c) | 21.1 mm |
| Loaded edge distance (a4,t) | 15.8 mm |
| Unloaded edge distance (a4,c) | 15.8 mm |
Timber (pointside) — α = 0°
| Spacing parallel to grain (a1) | 26.4 mm |
| Spacing perpendicular to grain (a2) | 21.1 mm |
| Loaded end distance (a3,t) | 80.0 mm |
| Unloaded end distance (a3,c) | 21.1 mm |
| Loaded edge distance (a4,t) | 15.8 mm |
| Unloaded edge distance (a4,c) | 15.8 mm |
Lateral Design Capacity
| Arrangement | Timber–timber, single shear (screw) |
| Length ℓ → embedded penetration tpen (= mode bearing length) | 120 → 75.0 mm |
| Effective threaded penetration lef | 75.0 mm |
| Effective diameter def | 5.28 mm (1.1·d1) |
| Regime | bolt rules (d > 6) |
| Governing mode | c |
| My,Rk | 13618 N·mm |
| Fv,Rk per bolt | 3756.1 N |
| γM,connection | 1.30 |
Fully threaded → no smooth shank; def = 1.1·d1 (§8.7.1(6)). lef = embedded penetration = 75.0 mm.
Fv,Rd = kmod · Fv,Rk / γM — per EC5 Table 3.1 load-duration class:
| Load duration | kmod | Rd (N) | kN |
|---|---|---|---|
| Permanent | 0.6000 | 1734 | 1.73 |
| Long-term | 0.7000 | 2023 | 2.02 |
| Medium-term | 0.8000 | 2311 | 2.31 |
| Short-term | 0.9000 | 2600 | 2.60 |
| Instantaneous | 1.1000 | 3178 | 3.18 |
Axial Capacity (Withdrawal / Tensile) — EC5 §8.7.2
| Withdrawal parameter fax,k (Eq 8.39) | 12.95 N/mm² |
| Withdrawal capacity Fax,Rk (Eq 8.38) | 7768.9 N |
| Screw tensile capacity | 10857.3 N |
| Governing axial (withdrawal) | 7768.9 N |
Fax,Rd = kmod · Fax,Rk / γM — per EC5 Table 3.1 load-duration class:
| Load duration | kmod | Rd (N) | kN |
|---|---|---|---|
| Permanent | 0.6000 | 3586 | 3.59 |
| Long-term | 0.7000 | 4183 | 4.18 |
| Medium-term | 0.8000 | 4781 | 4.78 |
| Short-term | 0.9000 | 5378 | 5.38 |
| Instantaneous | 1.1000 | 6574 | 6.57 |
Not checked: headPullThrough (ETA-dependent).
Assumptions & advisory notes
- Geometry: ℓ = 120 mm, headside 45 mm, pointside 90 mm → embedded penetration tpen = 75.0 mm; embedded threaded penetration lef = 75.0 mm.
- Pointside bearing length in the Johansen mode equations = tpen_emb = 75.0 mm (embedded penetration, EC5 Fig. 8.4) — not the full member thickness 90 mm.
- Effective diameter def = 5.28 mm — Fully threaded → no smooth shank; def = 1.1·d1 (§8.7.1(6)). lef = embedded penetration = 75.0 mm. Bolt-rules regime (outer d 8 mm, §8.7.1(4)).
- Lateral embedment: bolt rules (Eq 8.32 + Hankinson). Johansen modes run on def.
- Rope effect (§8.2.2(2)) capped at 100% of the Johansen part for screws; Fax,Rk = governing axial capacity 7769 N.
- Axial withdrawal α taken as 90° (screw axis perpendicular to grain — typical face insertion).
- Head pull-through is ETA-dependent and NOT checked here (see axial block).
- Predrilling required (EC5 §10.4.5(1)): lead hole = shank diameter over the shank length; ≈70% of shank diameter over the threaded portion.
Fv,Rk (char.)3.76 kN
Permanent1.73 kN
Long-term2.02 kN
Medium-term2.31 kN
Short-term2.60 kN
Instantaneous3.18 kN