--- title: "TC120 — composition, equivalents and standards" description: "TC120 is a designation in ISO for the grade also listed as C120U. Designations recorded for this grade: 11." canonical: https://steelequivalents.com/materials/iso/tc120 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/iso/tc120.md cs: https://steelequivalents.com/cs/materiály/iso/tc120.md de: https://steelequivalents.com/de/werkstoffe/iso/tc120.md es: https://steelequivalents.com/es/materiales/iso/tc120.md fr: https://steelequivalents.com/fr/matériaux/iso/tc120.md hu: https://steelequivalents.com/hu/anyagok/iso/tc120.md it: https://steelequivalents.com/it/materiali/iso/tc120.md nl: https://steelequivalents.com/nl/materialen/iso/tc120.md pl: https://steelequivalents.com/pl/materiały/iso/tc120.md pt: https://steelequivalents.com/pt/materiais/iso/tc120.md ru: https://steelequivalents.com/ru/материалы/iso/tc120.md tr: https://steelequivalents.com/tr/malzemeler/iso/tc120.md zh: https://steelequivalents.com/zh/材料/iso/tc120.md ja: https://steelequivalents.com/ja/材料/iso/tc120.md ar: https://steelequivalents.com/ar/المواد/iso/tc120.md ko: https://steelequivalents.com/ko/재료/iso/tc120.md pt-br: https://steelequivalents.com/pt-br/materiais/iso/tc120.md hi: https://steelequivalents.com/hi/सामग्री/iso/tc120.md content_hash: sha256:68383a9cae207b6a12216d1f538376db00afe0e7edbc07d3c5f64d7c7a40054d generated: 2026-09-22 --- > **Machine-readable Markdown rendering.** This is a Markdown representation of a web page, > served for AI agents and crawlers as a token-efficient alternative to the full HTML. > Full interactive HTML version: https://steelequivalents.com/materials/iso/tc120 > Canonical URL: https://steelequivalents.com/materials/iso/tc120 > Available languages: en, cs, de, es, fr, hu, it, nl, pl, pt, ru, tr, zh, ja, ar, ko, pt-br, hi > Change detection: `content_hash` is the SHA-256 of this document's Markdown body — everything > below this block, whitespace-trimmed, excluding the front-matter. Compare it to detect a real > content change; `generated` moves on every render and is not a change signal. ISO · International · 11 designations # TC120 TC120 is a designation in ISO for the grade also listed as C120U. We list 11 designations recorded for this grade, in the standards DIN / EN, BS, AFNOR, ISO, JIS, GB, GOST and KS. - *Designations* **11** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=49cb3c97-aad2-481b-a187-76520235e4f5&designation=0571ca7c-b6d7-409f-9294-33a9d128d70f "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/iso/tc120.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [GB T12 This grade’s own name](/materials/gb/t12 "GB T12") ## Also known as 11 designations · 8 standards · nothing hidden This grade’s own name recorded in our sources as this grade’s own designation under that standard. Indicative taken from a published cross-reference table; a close match, not a guarantee of interchangeability. Verify against the mill certificate before ordering. Withdrawn designation no longer current — a separate column from the two above, so a name can be same grade and withdrawn at once. DIN / EN Europe · 2 - [C120U Indicative](/materials/din-en/c120u "DIN / EN C120U") - [C125W2 Indicative](/materials/din-en/c125w2 "DIN / EN C125W2") BS United Kingdom · 2 - [BW1C Indicative](/materials/bs/bw1c "BS BW1C") - [C120U Indicative](/materials/din-en/c120u "BS C120U") AFNOR France · 1 - [C120U Indicative](/materials/din-en/c120u "AFNOR C120U") ISO International · 2 - [C120U Indicative](/materials/din-en/c120u "ISO C120U") - **TC120 Indicative** JIS Japan · 1 - [SK120 Indicative](/materials/jis/sk120 "JIS SK120") GB China · 1 - [T12 This grade’s own name](/materials/gb/t12 "GB T12") GOST Russia / CIS · 1 - [У12-1 Indicative](/materials/gost/u12-1 "GOST У12-1") KS South Korea · 1 - [STC2 Indicative](/materials/ks/stc2 "KS STC2") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 7 elements on file · weight % What this alloy is Fe C Cr Si Iron — the balance, never listed by a standard — 97.7 % C — 1.2 % Cr — 0.3 % Si — 0.3 % Traces & impurities · 0.6 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 1.15–1.24 — Unusual | | Si | 0.17–0.37 | | Mn | 0.1–0.4 | | P | ≤ 0.03 | | S | ≤ 0.025 | | Cr | ≤ 0.3 | | Cu | ≤ 0.25 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Copper 0.01 % 0.1 % 1 % 10 % 100 % The scale is logarithmic, not the element’s raw share of the alloy — the only honest way to fit 0.01 % and 100 % in one picture, and it means every value here can be compared with every other. | Element | As published source text, verbatim | Min% by weight | Max% by weight | Bound | |---|---|---|---|---| | C | 1.15-1.24 | 1.150 | 1.240 | Range | | Si | 0.17-0.37 | 0.170 | 0.370 | Range | | P | ≤0.03 | — | 0.030 | Max | | S | ≤0.025 | — | 0.025 | Max | | Cr | ≤0.3 | — | 0.300 | Max | | Mn | 0.1-0.4 | 0.100 | 0.400 | Range | | Cu | ≤0.25 | — | 0.250 | Max | The published column is the source string byte-for-byte, decimal comma and all; Min and Max are the parsed bounds. Elements not listed have no value on file — they are omitted, never inferred. ## Predicted transformation temperatures Not enough recorded composition to predict a transformation temperature for this grade — missing: Ni, Mo. ## Physical & mechanical properties An absent property means we hold no value for it — it is left out rather than estimated, interpolated from a neighbouring grade, or filled from a handbook. It does not mean the property is undefined for the material. ## Properties by condition 0 conditions · 0 values 1 further values are held for this grade under a condition the source did not name — a bound with no quantity attached. They are withheld rather than shown against a guessed condition. ## Heat treatment **GB /T 1299-2025** Single operation Test specimen - Quenching 760–780 °C Cooling Water Supply condition - Quenching Test specimen - Annealing Supply condition Conditions the standard permits on delivery. No temperature or medium is published for these, so no order and no alternation is implied. Source: [www.caishuku.com](https://www.caishuku.com/detail/azhlNWIxMzUxMDQ_ "Source: www.caishuku.com") ## Looking for this grade under another name? Search the catalogue by designation, material number or composition — every name on this page is itself a way in. [Search](/search "Steel grade search")[Inquiry](/inquiry?material=49cb3c97-aad2-481b-a187-76520235e4f5&designation=0571ca7c-b6d7-409f-9294-33a9d128d70f "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/iso/tc120.pdf "Datasheet as PDF")