Sensorium™ SmartBolt — Instrumented Fastener
Datasheet · sensorium-smart-bolt-datasheet · Revision Draft (Preliminary) · 2026-07-18
PRELIMINARY — PROPOSED VALUES. Values marked ‡ are proposed, industry-typical figures for this product class, provided so no specification is left blank. They are not measured and not final, and no value in this document is a certification claim. Engineering must confirm every ‡ value before this datasheet is released as final. The SmartBolt provides monitoring support — it is not a certified structural-health-inspection system. See §12 for change control.
Figure FIG-001 — Sensorium™ SmartBolt, the instrumented Sense-layer fastener of the Sensorium™ family.
1. At a glance
The Sensorium™ SmartBolt is a Sense module of the 5Tech Sensorium™ family, built on the BLE smart sensor-node platform: an instrumented structural fastener that installs in place of a standard bolt. A preload-sensing element in the instrumented head cavity‡ measures the axial clamping force (preload) directly, alongside temperature, vibration, and looseness signals, and streams that data over Bluetooth Low Energy to the Sensorium™ Gateway. On the 5Tech Platform, the data supports condition monitoring, trend visibility, and maintenance alerts — monitoring support, not a certified structural-health inspection or a substitute for scheduled inspection.
| Product | Sensorium™ SmartBolt (Instrumented Fastener) |
| Family / role | Sensorium™ · Sense |
| Function | In-fastener monitoring of preload/clamping-force, temperature, vibration & looseness (monitoring support) |
| Sensing | Preload-sensing element in the instrumented head cavity‡; MEMS accelerometer; head-temperature sensor |
| Size / grade | M12–M24‡ family · property class 8.8 / 10.9 / 12.9‡ per ISO 898-1 |
| Strength | Load-bearing shank not machined — retains the full rated strength of its property class‡ |
| Connectivity | Bluetooth Low Energy 5.x to the Sensorium™ Gateway |
| Enclosure / IP | Sealed hex head with head-integrated antenna; IP67‡ (IEC 60529) |
| Power | Sealed-for-life Li-SOCl₂ primary cell‡; ≥ 10 yr‡ service life (not field-replaceable) |
Key features
- Direct mechanical replacement for an equivalent-grade structural fastener: all electronics, the primary cell, and the antenna live in an instrumented head cavity, and the load-bearing shank is not machined or bored, so the bolt retains the full rated strength (proof load, tensile, and fatigue) of its ISO 898-1 property class (see §5).
- Direct preload measurement — a sensing element in the head cavity reports axial clamping force to ±2 %‡ of reading, so joints are tensioned to a measured clamp load instead of an inferred torque value.
- Temperature, vibration, and looseness sensing at the fastener to flag preload loss and abnormal joint condition over time.
- BLE 5.x streaming to the Sensorium™ Gateway — no per-bolt wiring runs; antenna in the exposed head.
- Sealed-for-life Li-SOCl₂ cell, ≥ 10 yr‡ service life; not field-replaceable — end-of-life removal and hazardous-waste disposal route in §8.
- Feeds the 5Tech Platform for condition monitoring, trends, and maintenance alerts — monitoring support, not a replacement for periodic manual torque / inspection checks.
Typical applications
- Structural and equipment joints where fastener preload / looseness should be monitored.
- Construction-site and asset monitoring (alongside Zone Awareness) via the 5Tech Platform.
- Condition-based maintenance programmes that want fastener preload / looseness trends alongside inspection.
2. System context
The SmartBolt is a Sense device: it originates data. Its measurements flow up through the Sensorium™ Gateway (Connect) to the 5Tech Platform (Decide), where monitoring, automation, and AI assistance turn preload and looseness trends into alerts, trends, and maintenance recommendations.
Figure FIG-002 — Sense → Connect → Decide. The SmartBolt is a Sense device streaming over BLE to the Gateway.
- Sense — the Sensorium™ SmartBolt (preload / vibration sensing) and Zone Awareness devices.
- Connect — the Sensorium™ Gateway aggregates and pre-processes SmartBolt data.
- Decide — the 5Tech Platform (Monitoring · Automation · AI assistance) turns data into trends and maintenance alerts.
- Solutions — Construction Sites Monitoring is built on this chain.
3. Functional overview
Figure FIG-003 — Longitudinal cross-section: preload-sensing element, electronics, primary cell, and antenna housed in the instrumented head cavity; the load-bearing shank is unmodified.
The SmartBolt integrates sensing and radio inside an instrumented head cavity, so the mechanical joint and the measurement point are one and the same, without weakening the load-bearing shank:
- Preload sensing — a sensing element in the head cavity (
‡, method under engineering confirmation) responds to the axial clamp load carried by the bolt, giving a measured clamping / preload force in service rather than an inferred torque value. - Temperature sensing — a temperature sensor at the bolt head reports fastener temperature, both as a joint-condition signal and to compensate the preload reading over temperature.
- Vibration & looseness sensing — a MEMS accelerometer monitors vibration and movement-related signals over time to flag looseness and preload loss.
- Wireless streaming — the in-head electronics transmit measurements over Bluetooth Low Energy to the Sensorium™ Gateway via an antenna in the exposed head.
- Monitoring — on the 5Tech Platform, preload, temperature, and looseness trends are visualized and drive maintenance alerts and recommendations (monitoring support, not certified structural-health inspection).
Data path: bolt sensing (head cavity) → in-head BLE radio → Sensorium™ Gateway → 5Tech Platform (monitoring & alerts). Exact sensing-element design, sampling, and measurement ranges are ‡ proposed and subject to engineering confirmation.
4. Ordering information
Order codes below are the proposed scheme; the base identifier and suffixes are ‡ pending confirmation. Configure = base size + property class + length/coating option. One thread size and one property class per order code.
| Order code | Configuration | Notes |
|---|---|---|
SEN-SB-100‡ |
Base SmartBolt | Preload / temperature / vibration sensing, BLE to Gateway; size + class per suffix |
SEN-SB-100-L‡ |
Alternate length variant | Same instrumentation, different shank length / grip |
SEN-SB-100-X‡ |
Extended / special variant | Alternate property class or coating variant |
Size (M12–M24‡) and property class (8.8 / 10.9 / 12.9‡) are selected per order code; accessories in §10.
5. Mechanical specifications
Figure FIG-005 — Elevation with overall length, thread, and across-flats dimensions (mm). Values ‡ proposed.
| Parameter | Value | Condition / note |
|---|---|---|
| Nominal thread size family | M12–M24‡ (ISO metric coarse) | One size per order code; direct replacement for an equivalent-grade standard bolt |
| Property class | 8.8 / 10.9 / 12.9‡ | Per ISO 898-1; selectable per order code; class marked on head |
| Strength integration | Instrumented head cavity; shank not machined‡ | Retains full rated strength of the property class (see strength note below) |
| Overall length | 60–200‡ mm | Per variant / joint grip length |
| Thread length | Per ISO 4014 / 4017‡ | Partially or fully threaded per variant |
| Head type / across-flats | Hex, DIN 931 / 933 profile‡ | Head enlarged to house instrumentation; across-flats per size |
| Weight | e.g. 70 g (M12) … 480 g‡ (M24) | Instrumented head adds mass vs a plain bolt |
| Coating / finish | Zinc-flake per ISO 10683‡ (Cr(VI)-free) | Salt-spray class in §8 |
| Ingress protection | IP67‡ (IEC 60529) | Sealed-for-life head assembly; see §8 |
| Fatigue life | ≥ 2 × 10⁶‡ load cycles | Alternating stress amplitude σ_A ≤ 50 MPa‡ on the stress area about the installed preload, per VDI 2230 S-N; equal to an unmodified fastener of the same class |
Strength & derating. All electronics, the primary cell, and the antenna are housed in an instrumented head cavity; the load-bearing shank is not machined, bored, or fitted with a strain-gauge bore. The SmartBolt therefore retains the full rated proof load, tensile strength, and fatigue life of its ISO 898-1 property class, and is a defensible direct replacement for an equivalent-grade fastener — there is no strength derating factor applied to the shank. (Were a future variant to machine a shank strain-gauge bore, a derating factor on proof/tensile load would be stated here instead.)
Proof load & tensile per size (computed for representative class 10.9; values scale per selected class per ISO 898-1 and are ‡ until a conformance report is on file):
| Size | Stress area A_s | Proof load F_p‡ (10.9, S_p = 830 MPa) | Min. tensile F_m‡ (10.9, R_m = 1040 MPa) | Typ. install preload‡ (≈ 0.7 F_p) |
|---|---|---|---|---|
| M12 | 84.3 mm² | 70 kN | 88 kN | 49 kN |
| M16 | 157 mm² | 130 kN | 163 kN | 91 kN |
| M20 | 245 mm² | 203 kN | 255 kN | 142 kN |
| M24 | 353 mm² | 293 kN | 367 kN | 205 kN |
Tightening & preload control. Installation is preload-controlled: the SmartBolt's live preload reading is used to tension the joint to its target clamp load, rather than relying on a torque value. Where a reference tightening torque is published, it assumes class 10.9 with a lubricated thread/underhead condition (tightening factor k = 0.14‡) via T = k · F · d — e.g. an M20 class-10.9 joint tensioned to ≈ 142 kN corresponds to ≈ 398 N·m‡ at k = 0.14. Torque is a cross-check only; the actual clamp load is set by the measured preload, per VDI 2230 joint design. Clamping-force measurement range and accuracy are in §6.
6. Electrical & sensing specifications
All values are ‡ proposed and stated with their measurement condition. The SmartBolt is a self-powered wireless node; there are no external electrical connections.
| Parameter | Min | Typ | Max | Unit | Condition |
|---|---|---|---|---|---|
| Preload / clamping-force measurement range | 0 | — | 290‡ | kN | Family span M12–M24; per size = 0…proof load of the selected class (§5) |
| Preload-measurement accuracy | — | ±2‡ | — | % of reading | −20 … +80 °C, referenced to a calibrated load cell (ISO 376‡) |
| Preload resolution | — | 0.1‡ | — | kN | @ 25 °C |
| Temperature measurement range | −40‡ | — | +85‡ | °C | At the bolt head |
| Temperature accuracy | — | ±2‡ | — | °C | −20 … +80 °C |
| Vibration / looseness sensing | — | — | ±16‡ | g | MEMS accelerometer, 0–2 kHz‡; movement-related signals |
| Sampling / reporting interval | 1‡ | 60‡ | 1440‡ | min | Configurable via Platform; default 60 min‡ |
| Radio | — | +4‡ | — | dBm | BLE 5.x, 2.4 GHz conducted TX power; see §7 |
| Power source | — | — | — | — | Sealed-for-life Li-SOCl₂ primary cell‡; not field-replaceable (see §8 disposal) |
| Battery service life | 10‡ | — | — | yr | @ 60 min‡ reporting interval, 25 °C; exceeds typical monitored fatigue life (§5) |
7. Interfaces & protocols
Figure FIG-004 — Multiple SmartBolts stream preload, temperature, and vibration data over BLE to a single Sensorium™ Gateway.
| Interface | Specification | Notes |
|---|---|---|
| Wireless uplink | Bluetooth Low Energy 5.x, 2.4 GHz | To the Sensorium™ Gateway |
| Antenna | Integrated in the exposed hex head‡ | Radiates from the head above the joint face; the shank and joint steel sit below the antenna |
| Wireless range | 10 m‡ installed / 30 m‡ free-air | +4 dBm‡ TX, BLE, line-of-sight; installed = bolt torqued into a steel joint (steel attenuates), free-air = unobstructed |
| Bolts per Gateway | Up to 50‡ Sensorium nodes/Gateway | SmartBolts share the Gateway's BLE node budget with Zone Awareness nodes |
| Provisioning / commissioning | Handheld wake/enroll tool + device ID‡ | Field association to a Gateway |
| Payload | Preload/clamping-force, temperature, vibration & looseness signals | Streamed to the 5Tech Platform via the Gateway |
Security. The SmartBolt↔Gateway BLE link uses BLE LE Secure Connections pairing‡; the authenticated, encrypted uplink to the 5Tech Platform (MQTT over TLS) is provided by the Gateway. The SmartBolt does not connect to the Platform directly.
8. Environmental & ratings
Structural fasteners operate in outdoor, loaded, and vibrating environments. All figures below are ‡ proposed targets, not yet verified by test.
| Parameter | Value | Standard / condition |
|---|---|---|
| Ingress protection | IP67‡ | IEC 60529; sealed-for-life head assembly |
| Operating temperature | −40 °C to +85 °C‡ | Ambient, under load |
| Storage temperature | −40 °C to +85 °C‡ | Li-SOCl₂ cell storage limit |
| Humidity | 5–100 % RH‡ | Condensing permitted (sealed head, IP67) |
| Vibration | 10–500 Hz, 10 g‡, 20 sweeps/axis | IEC 60068-2-6, installed in a representative joint |
| Shock | 50 g‡, 11 ms half-sine, 3 shocks/axis/direction | IEC 60068-2-27 |
| ESD immunity | ±8 kV contact / ±15 kV air‡ | IEC 61000-4-2 |
| Radiated RF immunity | 10 V/m, 80 MHz–2.7 GHz‡ | IEC 61000-4-3 |
| Corrosion resistance | ≥ 720 h‡ neutral salt spray, no red rust | ISO 9227 (NSS); zinc-flake coating per ISO 10683 |
End-of-life & disposal. The primary cell is sealed inside the head for life and cannot be replaced. At end of service, remove the fastener intact (do not open, machine, heat, or incinerate it — see the manual Safety chapter) and dispose of it as hazardous waste / a lithium-battery-containing device per local regulations. Do not place it in general or scrap-metal waste. Battery transport is subject to UN 38.3 (see §9).
9. Compliance & standards
No certification is currently held. The table lists the intended certification programme; no
mark below may be shown on the product, packaging, or marketing until certified with a report on
file (recorded in references.md).
| Area | Intended standard | Status |
|---|---|---|
| Radio / telecom (per region) | FCC Part 15 / ISED RSS-247 / RED (EU) for the 2.4 GHz BLE radio‡ | Planned — not yet submitted |
| Fastener mechanical property class | ISO 898-1 (proof load, tensile, hardness)‡ | Planned — conformance testing not yet on file |
| EMC (radio) | EN 301 489-1 / -17‡ | Planned — not yet tested |
| Environmental (materials) | RoHS (EU 2011/65) / REACH‡ | Planned — declaration pending |
| Battery transport | UN 38.3 (Li primary cell)‡ | Planned — assessment pending |
Radio type-approval is required before the product may be sold in any market; it is not yet held. The SmartBolt is monitoring support and is not a certified structural-health-monitoring (SHM) or structural-inspection system; no such claim is made or implied.
10. Accessories & related products
Figure FIG-006 — SmartBolt size/type variants alongside matched nuts, washers, and field tooling.
| Item | Order code | Purpose |
|---|---|---|
| Matched nut | SEN-SB-ACC-NUT‡ |
Correct mating hardware (class-matched) |
| Hardened washer set | SEN-SB-ACC-WSH‡ |
Load distribution under head/nut |
| Field commissioning tool | SEN-SB-ACC-CMT‡ |
Wake/associate a bolt to a Gateway |
| Length / thread variants | SEN-SB-100-L‡ |
Joint-specific sizing |
Related documents
- Aggregated by: Sensorium™ Gateway datasheet — the Connect layer that receives this data.
- Manual:
manuals/sensorium-smart-bolt-manual/— installation, commissioning, service. - Installation:
installation/sensorium-smart-bolt-installation/— torque, association, checks. - Sensed alongside: Sensorium™ Zone Awareness datasheet.
- Works with: 5Tech Platform (Monitoring · Automation · AI assistance) — Construction Sites Monitoring.
11. Monitored signals & alert behaviour (illustrative)
Figure FIG-007 — Illustrative — a monitored signal crossing its configured alert threshold (or an abnormal trend) raises an alert; a person decides on any action. Representative behaviour, not measured data.
The SmartBolt reports its monitored signals — load/preload, temperature, and vibration — over BLE (via the Gateway) to the 5Tech Platform; when a signal crosses a configured threshold or shows an abnormal trend, the Platform raises an alert and a person decides on any action. These are illustrative condition indications only — the SmartBolt is not a certified structural-health- monitoring (SHM) system. Thresholds are configured per deployment.
| Signal | Example alert trigger‡ | Response |
|---|---|---|
| Preload / load (looseness) | Bolt preload drops below its configured band (looseness) | Alert + notify (person decides) |
| Vibration | Vibration rises above a configured threshold or trends abnormally | Alert + notify (person decides) |
| Temperature | Head temperature crosses a configured limit | Alert + notify (person decides) |
Illustrative — representative, not measured; trigger values ‡ proposed and configurable.
12. Revision & change control
| Revision | Date | Change | Author |
|---|---|---|---|
| Draft (Preliminary) | 2026-07-07 | Initial authored content; values [TBD]. |
Documentation |
| Draft (Preliminary, PROPOSED) | 2026-07-18 | Adopted head-cavity/unmachined-shank strength design (no derating); added real size family (M12–M24) and ISO 898-1 property class with proof-load/tensile table; added preload measurement range/accuracy/resolution, temperature sensing, fatigue-life basis (VDI 2230), preload-controlled tensioning with k = 0.14; set IP67 (IEC 60529); head-integrated antenna with installed/free-air BLE range and bolts-per-Gateway; sealed-for-life Li-SOCl₂ cell with disposal route; rewrote compliance as "no certification held" + planned programme; filled all [TBD] with conditioned ‡ values and specific test standards; standardized SmartBolt naming; added revision block. |
Documentation |
Full change history: revision.md. Sources and cited standards: references.md.
Specifications are preliminary; ‡ values are proposed and subject to engineering confirmation
and change. See revision.md for change control, references.md for sources, and
image_prompts.md for the figure/prompt index. Web publication target:
/resources/datasheets/smart-bolt/.