How values are checked
A number without a source is a rumour. Matipedia shows, for every value, which public sources state it, when they were checked, and where sources disagree.
1. The standard is the authority, not the evidence
EN, ASTM, JIS and most other standards are sold, not published. Each value names the clause that governs it (for example EN 10025-2:2019, Table 7), but the evidence shown is the public pages that reproduce it: mill datasheets, Declarations of Performance, engineering references and distributors.
2. Independent publishers, not page count
Two pages from the same company usually copy the same table, so they count once. The badge shows how many independent publishers state the value — or, when the text of the standard itself is publicly available (GOST 27772 is), that the value was read there:
- From the standardFrom the standard. Read in the text of the standard itself.
- ConfirmedConfirmed. Three or more independent publishers state this value.
- CorroboratedCorroborated. Two independent publishers state this value.
- Single sourceSingle source. Only one publisher checked so far. Treat with care.
- UnverifiedUnverified. No public source checked yet. Do not design with it.
3. Disagreements are kept, not hidden
When a source states a different figure, it is listed under the value with the likely reason: a different thickness band, a National Annex, a typo, a different gauge length. Often the disagreement is the most useful thing on the page — for example a popular design table giving S355 fu = 510 MPa, which is Eurocode 3's value for hollow sections; for plate and sections to EN 10025-2 it is 490 MPa.
4. How a source was compared
Each citation says whether the value was matched against an excerpt of the page or the whole document was read, and on what date. Excerpt checks are upgraded as pages are read in full.
5. Missing beats wrong
If no public source could be found for a value, the grade page lists it under “Not yet verified” instead of filling the gap from memory. Where a value is shown without sources (some timber classes today), it is marked Unverified.
6. Before you build
Use the edition of the standard your specification names, the National Annex of the country of construction, and the inspection certificate of the product delivered (EN 10204 type 3.1). Matipedia is there to find, compare and sanity-check values quickly — not to replace those.
Properties and symbols
- ReH
- Yield strength — Upper yield strength guaranteed by the product standard (minimum).
- Rm
- Tensile strength — Ultimate tensile strength. Product standards give a range or a minimum.
- A
- Elongation after fracture — Minimum elongation; depends on gauge length and test direction.
- Agt
- Elongation at maximum force — Total elongation at maximum force (εuk in Eurocode 2): the ductility measure for reinforcement.
- Rm/Re
- Tensile-to-yield ratio — k = (ft/fy)k in Eurocode 2. Higher means more strain hardening after yield.
- Fy/Fu
- Yield-to-tensile ratio — Capped in seismic grades (A992: 0.85) so members can yield before they break.
- KV
- Impact energy (Charpy V) — Minimum absorbed energy at the stated test temperature.
- fy
- Design yield strength — Nominal value used in design calculations (before partial factors).
- fu
- Design ultimate strength — Nominal ultimate strength used in design calculations.
- E
- Modulus of elasticity — Young's modulus for design.
- G
- Shear modulus — G = E / 2(1 + ν).
- ν
- Poisson's ratio — In the elastic range.
- α
- Coefficient of thermal expansion — Linear, near room temperature.
- ρ
- Density — Mass per unit volume.
- γ
- Unit weight — Weight per unit volume, for self-weight loads.
- fck
- Characteristic cylinder strength — 28-day characteristic compressive strength, 150×300 mm cylinder.
- fck,cube
- Characteristic cube strength — 28-day characteristic compressive strength, 150 mm cube.
- fcm
- Mean compressive strength — fcm = fck + 8 MPa.
- fctm
- Mean axial tensile strength — fctm = 0.30·fck^(2/3) up to C50/60.
- fm,k
- Bending strength — Characteristic bending strength.
- ft,0,k
- Tension parallel to grain — Characteristic tensile strength along the grain.
- fc,0,k
- Compression parallel to grain — Characteristic compressive strength along the grain.
- fv,k
- Shear strength — Characteristic shear strength.
- ρk
- Characteristic density — 5th-percentile density.
- ρmean
- Mean density — Mean density.
See every source on the sources page.