Printed from Kezuriba (kezuriba.net/en/materials/ti-gr2/)
CP titanium Grade 2
ISO S (heat-resistant alloys & titanium)Commercially pure titanium. Number: Grade 2 / UNS R50400. Standard: ASTM B348/B348M (bars and billets), B265 (sheet and strip), B338 (tubes for heat exchangers). For aerospace, AMS 4902 (sheet and strip) and AMS 4942 (seamless tubing).
🌐JIS and international equivalents
“Close” means composition or properties are not exactly the same. Before substituting, check the values in each standard.
| System | Designation | Number | Relation | Confidence |
|---|---|---|---|---|
| ASTM/UNS | CP titanium Grade 2 | Grade 2 / UNS R50400 | — | |
| JIS | Class 2bar designation TB340H; the sheet designation is not confirmed | JIS H 4600 (sheet and strip) / JIS H 4650 (bars) | close | Agrees in 2+ sources[10][14][6][8] |
| EN/DIN | 3.7035Engineering) / 3.7034 (Aerospace | DIN material number | equivalent | One source / reference[11] |
| GB | — | — | Not confirmed |
Differences between the equivalents (from the sources)
- JIS Class 2: Listed alongside ASTM Gr.2 as a corresponding grade by the Japan Titanium Society, Kobe Steel and Nippon Steel. However, the upper limits of O, Fe and H and the tensile strength range differ (JIS: O ≤0.20, Fe ≤0.25, H ≤0.013, tensile strength 340–510). The designation TB340H was confirmed in Aichi Steel's catalog (Class 2 of JIS H 4650)
- EN/DIN 3.7035: Listed in TIMET's alloy list as a German standard of TIMETAL 50A (ASTM Gr.2). French T-40 and British BS TA.2–5 are in the same row. The EN chemical designation could not be confirmed in primary sources
- GB : Some sources give TA2, but no primary source from a Chinese manufacturer or standards body could be reached
📄Related specifications (AMS, ASTM etc.)
Specifications called up on purchase orders and drawings. AMS are SAE aerospace material specifications, split by product form (bar, plate, forging), melting practice and heat treatment. Standard texts are paid, so only titles and scopes checked on the publishers’ public pages are shown.
| Spec | Scope | Confidence |
|---|---|---|
| B348/B348M-25 | Standard Specification for Titanium and Titanium Alloy Bars and BilletsBars and billets (annealed). Includes Grade 2 = UNS R50400 | Agrees in 2+ sources[1] |
| B265-25 | Standard Specification for Titanium and Titanium Alloy Strip, Sheet, and PlateStrip and sheet (annealed). Includes Grade 2 | Agrees in 2+ sources[2] |
| B338-17(2026) | Standard Specification for Seamless and Welded Titanium and Titanium Alloy Tubes for Condensers and Heat ExchangersSeamless and welded tubes for condensers and heat exchangers. Includes Grade 2 | Agrees in 2+ sources[17] |
| AMS 4902M | Titanium Sheet, Strip, and Plate Commercially Pure Annealed 40.0 ksi (276 MPa) Yield StrengthCommercially pure titanium sheet and strip (thickness up to 1 in), annealed. Equivalent to Grade 2 (listed as corresponding by the Japan Titanium Society, ATI, Carpenter and TIMET) | Agrees in 2+ sources[18][10] |
| AMS 4942H | Titanium Tubing, Seamless Annealed, 40.0 ksi (275 MPa) Yield StrengthCommercially pure titanium seamless tubing, annealed (listed by Carpenter as a Grade 2 standard) | One source / reference[19][7] |
| JIS H 4600:2012 | Sheet and strip. Includes Class 2 (the 2012 edition was confirmed in the JSA preview; whether a newer edition exists was not confirmed) | One source / reference[20] |
| JIS H 4650:2016 | Bars. Includes Class 2 (designation TB340H) (the JSA preview is the 2016 edition; the table of classes is outside the preview range) | One source / reference[21][8] |
All ASTM standards on Kezuriba: ASTM standards quick reference.
✈Main aerospace uses (as stated in the sources)
- Airframe skins and structural members (listed by ATI as applications of commercially pure titanium Grades 1–4 together; not a statement naming Grade 2 alone)[13]
- The aerospace material specifications AMS 4902 (sheet and strip) and AMS 4942 (seamless tubing) cover commercially pure titanium equivalent to Grade 2 (40 ksi yield strength class)[18][19][10]
⚗Chemical composition (mass %)
Ranges differ between specifications, so each one has its own column (dark figures agree in several sources, light figures come from one source).
| Element | Spec ① | Spec ② |
|---|---|---|
| N | ≤ 0.03[3][6][7] | ≤ 0.03[6][8][9] |
| C | ≤ 0.08[3][6][7] | ≤ 0.08[6][8][9] |
| H | ≤ 0.015[3][6][7] | ≤ 0.013[6][8][9] |
| Fe | ≤ 0.3[3][6] | ≤ 0.25[6][8][9] |
| O | ≤ 0.25[3][6][7] | ≤ 0.2[6][8][9] |
| Ti | Balance[3][6] | — |
- Spec ① ASTM Grade 2
- Spec ② JIS Class 2 (JIS H 4600 sheet, JIS H 4650 bars)
⚖Density
4.51 g/cm³
Agrees in 2+ sources[13][11][12][8]
ATI gives 0.163 lb/in³ and 4.51 (its product page gives 4.51–4.52); TIMET (50A), the Japan Titanium Society (commercially pure titanium) and Aichi Steel give 4.51
Calculate weight in CP titanium Grade 2 →💪Mechanical properties
“Reference” values are not specified minimums from the standard but figures published by makers and others.
| Condition | Tensile MPa | Yield MPa | Elong. % | Hardness | Type of value |
|---|---|---|---|---|---|
| Annealed (ASTM Grade 2) | ≥ 345 | ≥ 275 (275–450 for sheet and strip) | ≥ 20 | — | Specified value (Grade 2 of ASTM B265 / B348; listed by ATI and Nippon Steel) Agrees in 2+ sources[3][6] |
| Annealed (JIS Class 2: sheet H 4600, bars H 4650) | 340–510 | ≥ 215 | ≥ 23 | — | Specified value (JIS; listed by Nippon Steel, Aichi Steel (H 4650 bars), Japan Welding Engineering Society WES 7102 correction sheet (H 4600 sheet) and Japan Titanium Society) Agrees in 2+ sources[6][8][9][10] |
| Annealed (TIMETAL 50A = equivalent to ASTM Gr.2) | 485 | 345 | 28 | — | Typical value (TIMET) One source / reference[11] |
| Hardness (annealed) | — | — | — | HV 160 (Japan Titanium Society, JIS Class 2) / approx. HRB 80 (ATI, Grade 2) | Typical value (industry association and manufacturer) One source / reference[12][13] |
1 MPa ≈ 145 psi (0.145 ksi). Hardness conversion · unit converter
🔧Machinability notes (as stated in the sources)
- Can be machined the same way as austenitic stainless steel: low speed, heavy feed, rigid tooling, and plenty of chlorine-free cutting oil (ATI's commercially pure titanium material)[13]
- Machinability is close to SUS304, but seizure is likely when cutting heat rises. Use low cutting speed, somewhat coarse feed and plenty of cutting fluid for cooling, and replace tools early (the edge tends to chip suddenly after initial wear). Parts deform easily under their own weight, cutting force, clamping force and thermal expansion, so take care with dimensional control (Japan Titanium Society; a description of titanium in general)[15]
- A case in which, while finishing a commercially pure titanium round bar on a lathe, the chips ignited at the cutting edge of the tool and the fire spread to the fine chips piled up at the operator's feet. Countermeasures: appropriate cutting conditions and regular cleaning so that chips do not accumulate (Japan Titanium Society trouble case)[16]
- Because thermal conductivity is poor and strength is retained at high temperature, heat and cutting force concentrate at the cutting edge. Chips are thin and prone to adhesion. If the speed is too high, the chip and tool material react chemically and the edge suddenly chips (Sandvik Coromant's explanation of ISO S, titanium)[4]
📚Sources
Primary sources (public documents from makers, industry associations and standards bodies), numbered where each value is cited. Many are in Japanese.
- store.astm.org https://store.astm.org/b0348_b0348m-25.html
- store.astm.org https://store.astm.org/b0265-25.html
- atimaterials.com https://www.atimaterials.com/Products/ati-cp2
- sandvik.coromant.com https://www.sandvik.coromant.com/en-us/knowledge/materials/workpiece-materials
- kyocera.co.jp https://www.kyocera.co.jp/prdct/tool/wp-content/uploads/2014/07/2024-2026_A.pdf#page=3
- nipponsteel.com https://www.nipponsteel.com/product/titan/pdf/index01.pdf
- carpentertechnology.com https://www.carpentertechnology.com/alloy-finder/cp-ti-grade-2
- aichi-steel.co.jp https://www.aichi-steel.co.jp/_assets/dl/products/stainless_company/titanium/titanium_cata…
- webdesk.jsa.or.jp https://webdesk.jsa.or.jp/pdf/jwes/errata/WES_7102_000_000_j___2012_rec_1_202112.pdf
- titan-japan.com https://www.titan-japan.com/technology/titanium.html
- timet.com https://www.timet.com/assets/local/documents/technicalmanuals/TiAlloys.pdf
- titan-japan.com https://www.titan-japan.com/technology/physical_properties.html
- atimaterials.com https://www.atimaterials.com/Products/Documents/datasheets/titanium/commerciallypure/ati_c…
- kobelco.co.jp https://www.kobelco.co.jp/products/advanced-materials/titan/pdf/spec.pdf
- titan-japan.com https://www.titan-japan.com/manufacturing/machining.html
- titan-japan.com https://www.titan-japan.com/pdf/trouble/trouble_fi8.pdf
- store.astm.org https://store.astm.org/b0338-17r26.html
- saemobilus.sae.org https://saemobilus.sae.org/content/ams4902m
- saemobilus.sae.org https://saemobilus.sae.org/content/ams4942h
- webdesk.jsa.or.jp https://webdesk.jsa.or.jp/preview/pre_jis_h_04600_000_000_2012_j_ed10_ch.pdf
- webdesk.jsa.or.jp https://webdesk.jsa.or.jp/preview/pre_jis_h_04650_000_000_2016_j_ed10_ch.pdf
Other materials
Titanium