Material number T31501: 1.2510
T31501 is the Unified Numbering System designation for 1.2510, cold-work tool steel, oil-hardening manganese-chromium-tungsten specified in EN ISO 4957.
Reading T31501 digit by digit
A UNS designation (ASTM E527 / SAE J1086) is a letter followed by five digits. The letter T marks the alloy family — here tool steels — and the five digits 31501 place the composition inside it, usually by carrying an older AISI or SAE number forward.
What a UNS number does not carry is the product form or the property level. T31501 therefore appears in several ASTM specifications — plate, bar, pipe, forging — each with its own mechanical requirements, and the number alone is not a complete purchase specification.
T31501 identity card
| Item | Value |
|---|---|
| UNS number (ASTM E527) | T31501 |
| Symbolic grade name | 1.2510 |
| Steel group | T — tool steels |
| Sequential number in group | 31501 |
| Specified in | EN ISO 4957 |
| Steel family | Tool steel |
| Also carries Werkstoff No. | 1.2510 |
| Tensile, same condition | ≈ 650–750 (typ.) MPa |
| Cross-references held | 8 grades in 5 systems |
1.2510 (100MnCrW4) is the oil-hardening cold-work tool steel AISI O1: 62–64 HRC as-quenched, 58–62 HRC in service, sharp edges and low cost. Composition, heat treatment and O1/SKS3 equivalents.
Full data sheet for 1.2510 → · Equivalent grades → · EN ISO 4957 →
UNS T — the neighbouring numbers
Same UNS letter, so the same alloy family. The digits generally carry an older AISI or SAE number.