Yes. Titanium is a conductive metal, but a poor one. Commercially pure Grade 2 has an electrical resistivity of 56 microhm-centimetres at room temperature, which works out to about 3 per cent of the conductivity of annealed copper. The spread behind that number matters more than the number: Grade 5 sits at 171, roughly three times more resistive than Grade 2, so the answer to whether titanium conducts depends on which titanium is on the drawing.
Resistivity and thermal conductivity, grade by grade
The values below are the room-temperature figures published in the RMI Titanium Company Titanium Alloy Guide (January 2000), taken from the per-grade data sheets of a single publication, so the grades sit on the same basis. The conductivity column is calculated from the resistivity against the International Annealed Copper Standard, in which 100 per cent IACS is defined as a resistivity of 1.7241 microhm-centimetres at 20 degrees C. The UNS numbers shown are given for cross-reference only. Grade 23 appears as R56407 here; R56401 is the number carried by ASTM F136 for the surgical implant form of the same alloy.
| Grade | UNS | Electrical resistivity (microhm-cm) | Approx. per cent IACS | Thermal conductivity (W/m·°C) |
|---|---|---|---|---|
| Grade 1 | R50250 | 54 | 3.2 | 20.8 |
| Grade 2 | R50400 | 56 | 3.1 | 20.8 |
| Grade 3 | R50550 | 56 | 3.1 | 19.7 |
| Grade 4 | R50700 | 60 | 2.9 | 17.3 |
| Grade 7 | R52400 | 56 | 3.1 | 20.8 |
| Grade 12 | R53400 | 52 | 3.3 | 19 |
| Grade 9 | R56320 | 126 | 1.4 | 8.3 |
| Grade 23 | R56407 | 165 | 1.0 | 7.3 |
| Grade 5 | R56400 | 171 | 1.0 | 6.6 |
Two things in that table are worth reading twice. Grade 12, an alloy people reach for because of its behaviour in hot brine, is the most conductive entry on the list, slightly ahead of unalloyed Grade 2. And the two columns broadly move together: the alpha-beta alloys are worse on both counts, with Grade 5 at roughly a third of Grade 2 electrically and thermally. The pairing is not exact row by row, though. Grade 12 has the lowest resistivity in the table and a thermal conductivity slightly below Grade 2’s.
One more thing to read carefully: these are one publication’s figures, and published values for the same grade do not all agree. The Beiyu Titanium Grade 2 data sheet gives 0.48 to 0.53 microhm-metres, which is 48 to 53 in the units above against RMI’s 56; the Grade 23 sheet gives 168 to 175 against RMI’s 165. Grade 5 is the one that agrees closely, 170 against 171. The spread comes from purity within the grade, product condition and measurement basis rather than from one source being wrong, and thermal conductivity behaves the same way, which is why our own data sheet quotes 16 to 22 W/m·K where the table above carries a single 20.8.
That spread is also the practical argument of this page. If a property this basic moves by roughly ten per cent between reputable published sources, a drawing that puts a limit on it needs a measured value on the order, not a handbook value copied from a table.
Why the alloyed grades are three times worse
The pattern inside the unalloyed grades is the first clue. Grades 1 through 4 differ from one another mainly in how much oxygen and iron the chemistry allows, and resistivity broadly follows: 54, 56, 56, 60. The trend is broad rather than strict. ASTM B348 allows Grade 3 more oxygen than Grade 2, 0.35 per cent against 0.25, yet both are printed at 56. Dissolved impurity atoms scatter conduction electrons, which is the standard explanation for resistivity rising with interstitial and iron content, but it does not resolve differences this small.
Grade 5 takes that mechanism much further. It is titanium with roughly 6 per cent aluminium and 4 per cent vanadium, an alloy content about an order of magnitude above the residual levels ASTM B348 allows in CP titanium, whose maxima add up to roughly 1 per cent all told, and it is two-phase rather than single-phase. Grade 23 is the same alloy held to tighter interstitial limits, and ASTM B348 puts numbers on that: oxygen at 0.13 per cent maximum against 0.20 for Grade 5, nitrogen 0.03 against 0.05, iron 0.25 against 0.40. That is a small change on top of a large alloy content, and the published figures are consistent with it: Grade 23 sits at 165 against Grade 5’s 171, nowhere near Grade 2. Grade 9, at 126, is the intermediate case its composition would suggest.
The practical version: choosing between Grade 2 and Grade 5 for strength or corrosion reasons also changes the electrical and thermal behaviour of the part by a factor of three, and that change is rarely on the table when the grade is chosen.
Where titanium’s conductivity is the point rather than the problem
Poor conductivity is not automatically a disadvantage. Three applications buyers bring to us turn on it directly.
| Application | What the resistivity does | What it means for the order |
|---|---|---|
| Impressed current anodes | The titanium is a substrate that carries current to a coating, not the electrode surface itself. Current has to travel from the connection through the substrate to the coating in a metal with 3 per cent of copper’s conductivity | Length, cross section and connection detail matter as much as grade, and the coating system is specified separately |
| Resistance welding of titanium parts | Heat is generated in proportion to resistance and to the square of the current, so titanium’s high resistivity and low thermal conductivity concentrate heat at the joint rather than bleeding it away | The grade is one input to the schedule, because Grade 5 and Grade 2 are three times apart in resistivity |
| Heat exchanger surfaces | Low thermal conductivity is offset by the thin walls titanium’s strength and corrosion resistance allow | Wall thickness and tube dimensions are part of the thermal answer, not just the material choice |
The anode case is the one buyers most often arrive at from this question. Our titanium anode guide for cathodic protection and the MMO coated anode guide cover how the coating and the substrate divide the work. For the thermal side, the Grade 2 heat exchanger page deals with wall thickness.
What a mill certificate will not tell you
ASTM B348 for bar and billet, ASTM B265 for plate and sheet, and ASTM B338 for tube are the specifications most titanium mill products are ordered against. None of them specifies electrical resistivity or thermal conductivity. They cover chemistry, mechanical properties and dimensions, so a certificate issued to any of them will be silent on the property this page is about.
| Specification | Product form | Times “resistivity” appears in the text | Where “conductivity” appears |
|---|---|---|---|
| ASTM B348 | Bar and billet | None | Only inside the title of ASTM E1447, the referenced hydrogen determination method |
| ASTM B265 | Strip, sheet and plate | None | Only inside the title of ASTM E1447 |
| ASTM B338 | Seamless and welded tube | None | Only inside the title of ASTM E1447 |
The single appearance of the word is worth understanding, because it is the sort of thing that gets misread in a hurry. ASTM E1447 is the method these specifications call up for measuring hydrogen in the chemistry, and its full title names thermal conductivity and infrared detection as the way the instrument reads the gas. It is an analytical technique sitting in the reference list, not a property the material is being held to. The oxygen and nitrogen method alongside it, ASTM E1409, uses inert gas fusion without any conductivity in its title. Nor is there a supplementary requirement to fall back on: B265’s supplementary requirements S1 to S3 cover surface bend testing, a yield strength ceiling and flatness, none of them electrical, while B338 and B348 carry no supplementary requirements section at all.
That is the reason handbook figures like the ones above exist and get quoted: they are typical values for the grade, not guaranteed values for the heat in front of you. For most parts that distinction never matters. It matters when a drawing puts a limit on resistivity or on conductivity, because there is then no clause in the material specification to invoke and the measurement has to be agreed on the purchase order along with the method and the temperature at which it is taken.
Common follow-up questions
Does titanium conduct electricity well enough to use as a conductor? No. At about 3 per cent IACS for CP grades and 1 per cent for Grade 5, titanium is a structural and corrosion material that happens to conduct, not a conductor. Where a titanium component has to carry meaningful current, sizing the titanium up to compensate runs into the section and weight the part was chosen to avoid, so the current path is normally solved separately from the titanium part.
Will titanium conduct electricity through its oxide layer? Not readily. The passive titanium dioxide film that gives titanium its corrosion resistance is a poor conductor, which is one reason electrical connections to titanium are made at prepared surfaces, and part of why bare titanium is not used as the working surface of an anode. It is also why a resistance measurement taken through an as-received surface can read very differently from the bulk figure.
Should resistivity decide between titanium and another alloy? Rarely. Neither titanium nor the stainless and nickel alloys it competes with is a conductor, and the figures that separate them are small next to the differences in corrosion behaviour, strength and density that normally drive the choice. Where resistivity genuinely is the deciding property, it belongs on the drawing as a limit rather than in a material comparison.
Does resistivity change with temperature? Yes, and the published figures above are room temperature values. For service well above or below ambient, the temperature of interest has to be stated, because a single room temperature number is not the answer to a high temperature question.
Is titanium conductive enough to bond or ground a structure through? Titanium will carry a bonding current, but two things get in the way and they are worth separating. The bulk resistivity is the smaller problem at 56 microhm-centimetres for Grade 2. The larger one is the passive oxide at the contact face, whose resistance is not a property of the grade at all and varies with how the surface was prepared. That is why a bonding measurement taken on an as-received surface tells you about the surface rather than about the titanium, and why contact preparation belongs on the drawing alongside any bonding resistance limit.
Is titanium magnetic? No, and that is a separate property with its own certificate problem. The permeability page covers it.
Specification detail with sources
The resistivity and thermal conductivity figures in the table are the room-temperature values printed in the RMI Titanium Company Titanium Alloy Guide, January 2000, in the section covering properties of commercially pure titanium and titanium alloys. The Grade 5 value of 171 microhm-centimetres is independently corroborated by the NASA Materials Data Handbook: Titanium 6Al-4V prepared under contract NAS8-26644, which lists electrical resistivity as 171 microhms-cm at 20 degrees C in its tabular abstract. The per cent IACS column is arithmetic against the International Annealed Copper Standard value of 1.7241 microhm-centimetres at 20 degrees C, not a separately published figure. The comparison figures quoted against RMI’s are the ones carried on the Beiyu Titanium Grade 2, Grade 5 and Grade 23 data sheets, and they are shown rather than reconciled because the disagreement between published sources is itself the point. The composition limits quoted for Grade 5 and Grade 23 are from the chemical requirements table of ASTM B348, whose scope covers titanium and titanium alloy bars and billets; the alloy identities of 6 per cent aluminium and 4 per cent vanadium are the descriptions B348 itself gives those grades in its scope clauses. As for the certificate: none of ASTM B348, B265 or B338 contains the word resistivity anywhere in its text, and the only occurrence of conductivity in each is inside the title of the referenced hydrogen test method, ASTM E1447. All three set chemical, mechanical and dimensional requirements and stop there.
What to put on the enquiry
Resistivity and thermal conductivity are not certificate items on any of the three specifications above. So a drawing that carries a limit needs the enquiry to carry four things a certificate issued to those specifications alone will not show: the limit itself, the test method, the temperature the measurement is taken at, and the grade. With those four, the additional test is quoted alongside the material instead of surfacing at inspection. Anode substrates need two more, the current path and the coating system, because those size the section further than the grade choice does. Beiyu Titanium supplies titanium in Grade 1, 2, 5, 7, 9, 12 and 23 as bar, plate, sheet, tube and forgings to ASTM and AMS specifications, with an EN 10204 3.1 mill test certificate by order scope. Grades 3 and 4 appear in the table above for the trend they show across the unalloyed grades, not as a supply offer.