Gauge is the number buyers ask for first and trust too much. In a wooden railway it is one of six interfaces that have to agree before two pieces can be used together, and it is the easiest to measure and the least likely to be the one that fails. This page separates the interfaces and gives the sample checks.
The figures here are references, not promises. Where a model has been measured, the page says so; where it has not, the field reads confirmed per model. No model page fills a missing gauge or connector with a guess.
Gauge is one number and four questions
Gauge is the distance between rail centres, not the width of the piece or the vehicle. A piece can match on gauge and still fail on rail profile, connector shape or track height, which is why the sample step is not optional.
| Term | What it describes | How a buyer checks it |
|---|---|---|
| Gauge | distance between rail centres | measure across rail centres on two pieces |
| Rail profile | cross-section of the rail | compare side by side, straight edge |
| Connector profile | shape and depth of the tab or peg | join, lift one end, look for gaps |
| Track height | rail top above the floor | measure at the join |
The 40 mm reference and what it does not promise
40 mm between rail centres is the standard reference for common wooden railway systems. It is a starting filter for a range, not a compatibility statement: two pieces can share the reference and still fail because the connector depth, rail profile or track height differ.
For procurement it gives one target for the range and a comparable figure for a new model. It is stated per model where checked; confirm it on a sample.
Connector types in wooden railway systems
Connectors fall into a small number of families. The type matters more than the millimetre, because the family decides how pieces seat, release and wear.
| Connector type | How it works | Common failure | What to check |
|---|---|---|---|
| Peg-and-slot joint | a tab enters a slot | loose fit, cracked tab | seat depth, gap, force to separate |
| Magnetic coupling | magnets in the vehicle ends | weak hold, magnet escaping | pull force, housing capture |
| Hook or peg coupling | a hook or pin on the vehicle end | hook shape differs, uncouples | hook opening, coupling height |
| Rail-to-rail socket | rail end sits into a socket | poor seating, rail spread | seating depth, rail alignment |
Test under load: a joint that seats on a table can separate on carpet or a ramp. Check it again after assembly.
Compatibility is a stack of interfaces
A layout joins in one direction: gauge, then rail profile and height, then connector, then coupling, then geometry. A failure at any level stops the layout even when the rest match.
| Level | What can differ | Symptom in use |
|---|---|---|
| Gauge | rail centres | rails do not line up |
| Rail profile | rail cross-section | vehicle rocks at the join |
| Track height | rail top height | ramps misalign |
| Connector | tab or peg depth | gap, or the join comes apart |
| Coupling | magnet or hook height | vehicles separate on gradients |
| Geometry | curve and switch angle | layout closes but will not run |
The practical rule is to test the full loop: a layout that connects in pairs can still fail when the last piece closes it.
What the range states and what it does not
| Statement | Status |
|---|---|
| Gauge reference per model family | stated where checked, otherwise confirmed per model |
| Connector type per pack | stated where documented |
| Fit with a named brand | not claimed anywhere on this site |
| Universal compatibility | not claimed anywhere on this site |
Compatibility with a named brand is a claim this range does not make. The site describes gauge reference and connector type; the buyer tests those against the layout.
What only the seller can answer
- Which model families share one connector family, and which only share the gauge reference.
- Whether a stated gauge was measured on a sample or supplied by the workshop.
- Which expansion pieces complete the anchor loop, and which are decoration only.
- What the range can be described as fitting without borrowing a brand name.
How to verify gauge and fit on a sample
- Measure across rail centres on two pieces, not on the vehicle.
- Put rails from both systems side by side and check profile and height with a straight edge.
- Join two pieces, lift one end and look for a gap.
- Build a full loop from the anchor set and the expansion pack together.
- Send an engine through every switch and ramp, loaded and unloaded.
- Repeat the loop on carpet, where small height differences show as derailments.
- Take it apart, rebuild it and check the joins for play.
- Photograph any failure point and send it with the model number.
Track geometry decides the expansion plan
Gauge gets pieces onto one layout; geometry decides whether it closes. Curves, switches, risers and adapters are planned against the anchor set's piece list, because an expansion pack only helps if its pieces complete something the set already has.
| Piece family | What the buyer needs to know | Why it decides the expansion |
|---|---|---|
| Straights | length and count | completes a loop |
| Curves | angle and count | closes a circle |
| Switches | hand and fit | adds play, complicates the loop |
| Risers and bridges | height and ramp length | vertical clearance |
| Adapters | connector change | joins a second system |
The track piece and expansion guide shows how to read a piece list, the gauge and size guide covers the buying side, and the benchmarks page gives the band-level view.
Data confidence on this site
Every specification carries a label that separates a fact from a placeholder.
| Label | Meaning |
|---|---|
| Measured | checked on a sample by the team, method noted |
| Workshop-stated | provided by the production partner, not re-measured |
| Confirmed per model | to be confirmed before order |
Treat the gauge reference as the start and the sample as the test. The packing and container data page covers the carton side.
What we record for each pack
| What is recorded | Why it matters | Where to find it |
|---|---|---|
| Gauge reference | Distance between the rail centres; the common wooden railway reference is 40 mm | Stated in the quotation; confirmed on the sample |
| Connector type | Magnet, tab-and-slot or pin: connectors are not interchangeable across producers | Confirmed on the sample per pack |
| Rail profile | Height and width of the rail; a pack can fit the gauge but not the profile | Checked on the sample |
| Curve radius and angle | Decides how tight a layout can turn | Measured on the sample for the models being ordered |
| Piece composition | What is in the pack (straight, curve, switch, scenery) | Model page specification table |
Coverage note
Gauge and connector are confirmed on the sample for each pack; they are not published as a universal fit table because producers differ. The model page states the fields that are already confirmed (MOQ, carton, lead time, material, age), and the quotation adds the connector for the pack being ordered.