Safety standards and certification
UL 508AActive pilot · industrial control panels
Engineering Library
Engineering calculators, verified component data, and practical references for electrical and mechatronics design.
2. Mechanical Reference
Mechanical Reference
Assembly references for electronics and mechatronics engineering work.
ScopeElectronics assembly
Primary referenceFastener torque
Reference families5 categories
UnitsMetric · Imperial
2.1
Electronics and mechatronics assembly
Fastener Torque Reference
Indicative values only
Use these conservative ranges as starting points for non-safety-critical assembly. Final torque must follow the product specification, supplier datasheet, material limits, or applicable assembly standard.
| Thread Size | Typical Range (N·m) | Typical Range (cN·m) | Typical Use Case | Notes |
|---|---|---|---|---|
| M2 | 0.08–0.15 | 8–15 | Small PCB mounting, miniature covers | Use the lower end for plastic bosses or delicate PCB assemblies. |
| M2.5 | 0.15–0.30 | 15–30 | PCB standoffs, small electrical assemblies | Confirm standoff and insert limits before tightening. |
| M3 | 0.25–0.50 | 25–50 | PCB/PBA mounting, covers, light brackets | Substrate and washer selection remain critical. |
| M4 | 0.60–1.20 | 60–120 | Sheet-metal brackets, enclosure covers | Avoid direct PCB loading without specified hardware. |
| M5 | 1.20–2.50 | 120–250 | Equipment brackets, enclosure hardware | Verify captive nut, insert, and sheet-metal capacity. |
| M6 | 2.00–4.00 | 200–400 | Supports for small electrical equipment | Use a qualified joint specification where safety is relevant. |
2.2
Wire and cable entry protection
Electrical Panel Hole Reference
The selected component controls the cut-out
Use this table to shortlist a wire-protection bushing. The released product drawing remains authoritative for mounting-hole tolerance, panel thickness, material, environmental rating and installation method. Never derive a cable-gland cut-out from its thread designation alone.
1
Determine the cable or bundle diameterUse the actual cable datasheet or calculate an initial bundle envelope.
2
Select a protective entry componentFilter for a passage diameter that is at least as large as the cable or bundle.
3
Release the manufacturer cut-outVerify the exact part, drawing, panel thickness and applicable approvals.
14 verified parts
| Family | Part Number | Mounting Hole Ø | Usable Passage / Bundle Ø | Selection Note | Official Source |
|---|---|---|---|---|---|
| Metric snap bushing | 2150MSB 13-10 | 13.0 mm | 10.0 mm inside Ø | Fixed smooth passage. | Heyco product table |
| Metric snap bushing | 2142MSB 16-12 | 16.0 mm | 12.0 mm inside Ø | Fixed smooth passage. | Heyco product table |
| Metric snap bushing | 2144MSB 20-16 | 20.0 mm | 16.0 mm inside Ø | Fixed smooth passage. | Heyco product table |
| Metric snap bushing | 2168MSB 22-18 | 22.0 mm | 18.2 mm inside Ø | Fixed smooth passage. | Heyco product table |
| Metric snap bushing | 2146MSB 25-19 | 25.0 mm | 19.0 mm inside Ø | Fixed smooth passage. | Heyco product table |
| Metric snap bushing | 2188MSB 28-24 | 28.0 mm | 24.0 mm inside Ø | Fixed smooth passage. | Heyco product table |
| Metric snap bushing | 2148MSB 32-26 | 32.0 mm | 26.0 mm inside Ø | Fixed smooth passage. | Heyco product table |
| Metric snap bushing | 2190MSB 34-26 | 34.2 mm | 26.2 mm inside Ø | Fixed smooth passage. | Heyco product table |
| Universal bushing | 2858SUB 500 | 12.7 mm | 7.6 mm max bundle Ø | Flexible shutters; panel ≤ 1.6 mm. | Heyco product table |
| Universal bushing | 2861SUB 625 | 15.9 mm | 11.1 mm max bundle Ø | Flexible shutters; panel ≤ 1.6 mm. | Heyco product table |
| Universal bushing | 2862SUB 750 | 19.1 mm | 12.7 mm max bundle Ø | Flexible shutters; panel ≤ 1.6 mm. | Heyco product table |
| Universal bushing | 2863SUB 875 | 22.2 mm | 14.3 mm max bundle Ø | Flexible shutters; panel ≤ 1.6 mm. | Heyco product table |
| Universal bushing | 2864SUB 1000 | 25.4 mm | 19.0 mm max bundle Ø | Flexible shutters; panel ≤ 1.6 mm. | Heyco product table |
| Universal bushing | 2158SUB 1093 | 27.8 mm | 20.6 mm max bundle Ø | Flexible shutters; panel ≤ 1.6 mm. | Heyco product table |
Source scope: Heyco official product tables, accessed 2 August 2026. Values are presented in the manufacturer's published units and rounded display equivalents. Confirm the current drawing before release.
2.3
ISO metric coarse threads
Metric Thread & Sheet-Metal Hole Reference
Tap drill is not the same as a clearance hole
Use the tap-drill diameter only when cutting an internal thread. Use an ISO 273 clearance hole when the screw passes through the sheet. Thin sheet may not provide sufficient thread engagement; consider a clinch nut, rivet nut, welded nut or qualified flow-drilling process.
| Thread | Coarse Pitch | Tap Drill | ISO 273 Fine Clearance | ISO 273 Medium Clearance | ISO 273 Coarse Clearance | Typical Decision |
|---|---|---|---|---|---|---|
| M2 | 0.40 mm | 1.60 mm | 2.20 mm | 2.40 mm | 2.60 mm | Tap 1.6; through-hole normally 2.4. |
| M2.5 | 0.45 mm | 2.05 mm | 2.70 mm | 2.90 mm | 3.10 mm | Tap 2.05; through-hole normally 2.9. |
| M3 | 0.50 mm | 2.50 mm | 3.20 mm | 3.40 mm | 3.60 mm | Tap 2.5; through-hole normally 3.4. |
| M3.5 | 0.60 mm | 2.90 mm | 3.70 mm | 3.90 mm | 4.20 mm | Tap 2.9; through-hole normally 3.9. |
| M4 | 0.70 mm | 3.30 mm | 4.30 mm | 4.50 mm | 4.80 mm | Tap 3.3; through-hole normally 4.5. |
| M5 | 0.80 mm | 4.20 mm | 5.30 mm | 5.50 mm | 5.80 mm | Tap 4.2; through-hole normally 5.5. |
| M6 | 1.00 mm | 5.00 mm | 6.40 mm | 6.60 mm | 7.00 mm | Tap 5.0; through-hole normally 6.6. |
| M8 | 1.25 mm | 6.80 mm | 8.40 mm | 9.00 mm | 10.00 mm | Tap 6.8; through-hole normally 9.0. |
| M10 | 1.50 mm | 8.50 mm | 10.50 mm | 11.00 mm | 12.00 mm | Tap 8.5; through-hole normally 11.0. |
| M12 | 1.75 mm | 10.20 mm | 13.00 mm | 13.50 mm | 15.00 mm | Tap 10.2; through-hole normally 13.5. |
Tap-drill source: Dormer Pramet ISO Metric HSS cutting-tap data. These values target conventional cutting taps; forming taps require different pilot holes.
Clearance source: ISO 273 fine, medium and coarse series as reproduced in Bossard technical resources. Medium is the normal general-purpose choice unless alignment, coating, tolerance stack or assembly access requires another fit.
2.4
Engineering Notes
- Use product- and material-specific limits before generic reference values.
- PCB, plastic, inserts, and sheet metal commonly require lower torque than general steel fastener tables.
- Record the governing source and revision for released assembly instructions.
Mechanical Support
Torque
Calculate static torque from an applied force and perpendicular lever arm, with common SI and imperial unit conversions.
Calculation basis
Perpendicular force
Typical Fastener Torque Reference
Indicative values only
These conservative ranges are starting points for non-safety-critical assembly work, not universal tightening specifications. Final torque must follow the product specification, supplier datasheet, material-combination limits, insert or standoff specification, or applicable internal assembly standard.
| Thread Size | Typical Range (N·m) | Typical Range (cN·m) | Typical Use Case | Notes |
|---|---|---|---|---|
| M2 | 0.08–0.15 | 8–15 | Small PCB mounting, miniature covers | Use the lower end for plastic bosses or delicate PCB assemblies. |
| M2.5 | 0.15–0.30 | 15–30 | PCB standoffs, small electrical assemblies | Confirm standoff and insert limits before tightening. |
| M3 | 0.25–0.50 | 25–50 | PCB/PBA mounting, covers, light brackets | Common assembly size; substrate and washer selection remain critical. |
| M4 | 0.60–1.20 | 60–120 | Sheet-metal brackets, enclosure covers | Usually unsuitable for direct PCB loading without specified hardware. |
| M5 | 1.20–2.50 | 120–250 | Equipment brackets, enclosure hardware | Verify captive nut, insert, and sheet-metal thread capacity. |
| M6 | 2.00–4.00 | 200–400 | Structural supports for small electrical equipment | Use a qualified joint specification where load or safety is relevant. |
Engineering Notes
- PCB assemblies often require lower torque than general steel fastener tables.
- Over-torque can damage PCBs, inserts, standoffs, threads, or plastic parts.
- Under-torque can cause loosening, poor grounding, or vibration issues.
- Required torque depends on screw grade, materials, lubrication, thread engagement, washers, insert type, plastic or metal substrate, and locking method.
5. Engineering Standards
Standards
Reference families used across electrical, mechanical, and assembly engineering work.
5.1
Standards Index
The planned families are intentional future work. They will become available only after suitable official sources and reviewed summaries are added.
5.1.1
Loading verified metadata…UL 508A · Industrial Control Panels
5.1.2
Source-bound question
Ask about the pilot topics: scope, edition/status, or what panel certification covers.
Wire sizing tool
AWG ↔ mm²
Convert American Wire Gauge to metric cross-sectional area, or find the nearest standard AWG size.
Supported range
4/0 to 40 AWG
01
Connecting to calculation service
Calculator
AWG
Enter 4/0, 3/0, 2/0, 1/0, or 1–40.
Cross-sectional area
—
mm²
Enter cross-sectional area to find the nearest standard AWG.
Nearest Standard AWG
—
04
Engineering Notes
- AWG values describe conductor geometry, not insulation diameter
- Metric entries return the nearest standard AWG size
03
Practical Guidance
Use the converted area for preliminary sizing, then verify ampacity, voltage drop, and the applicable wire specification.
AWG reference table
| AWG | Diameter (mm) | Cross-section (mm²) |
|---|---|---|
DC cable analysis
Voltage Drop
Calculate voltage drop, loop resistance, and cable power loss for a two-conductor DC copper circuit.
Calculation basis
Copper at 20°C
Conductor analysis
Cable Resistance
Calculate one-way conductor resistance, two-conductor loop resistance, and resistance per metre for a copper cable.
Calculation basis
Copper at 20°C
Current-carrying estimate
Wire Ampacity
Estimate the recommended continuous current for a single copper conductor installed in free air.
Reference conditions
Free air at 30°C
Cable routing
Minimum Bend Radius
Estimate the minimum routing radius and bending diameter from cable outside diameter and installation type.
Calculation basis
Cable diameter factor
Logistics and mechanical design
Cable Weight
Estimate conductor weight per metre and total conductor weight from material, cross-section, quantity, and length.
Calculation basis
Conductor metal mass
Routing and duct design
Bundle Diameter
Estimate the circularized outside diameter of a bundle made from identical round wires.
Calculation basis
64% packing allowance
1. Electrical / 1.1 Wire
Wire
Reference data, standards, engineering guidance, and design methods for electrical wire.
ScopeElectrical conductors
ReferenceManufacturer records
StandardsUL · IEC · SAE
Design Tools7 available methods
Engineering Database
Wire Database is currently empty.
Import verified manufacturer data or request a wire for review.
| Certification | Color | Actions | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
1.1.2
Standards
1.1.3
Engineering Notes
Ampacity is contextual. Account for insulation, ambient temperature, bundling, and termination limits.
Use operating temperature. Correct conductor resistance before voltage-drop analysis.
1.1.4
Context ready when a wire is selectedDesign Tools
1. Electrical / 1.1 Wire / Active Context
Wire details
Context
Standards
Context
Engineering Notes
Verify before release. Confirm manufacturer data, installation conditions, and applicable derating requirements.
Context
Design Tools
Context
Related Topics
1. Electrical / 1.3 Connector
Connector Database
Browse connector housings and their documented terminal compatibility.
Engineering Database
No connector records are available.
Molex Mini-Fit Jr. will be the first pilot family.
| Manufacturer | Series | Part Number | Connector Type | Positions | Certification |
|---|---|---|---|---|---|
Engineering Database / Connector
Connector details
1. Electrical / 1.4 Terminal
Terminal
Manage traceable terminal, contact, and ferrule data with documented wire compatibility.
Engineering Database
Terminal Database is currently empty.
Import verified manufacturer data or request a terminal for review.
| AWG Range | mm² Range | Certification | Actions | ||||||
|---|---|---|---|---|---|---|---|---|---|
Engineering Database / Terminal