Whether titanium is heavy depends entirely on what you are putting it next to, and the two answers point in opposite directions. Against steel, no: titanium is a little over half the weight, and that is usually why it is on the drawing. Against aluminium, yes: titanium is roughly two thirds heavier. The question only becomes useful once you know which of those two comparisons you are actually making, and once the density is attached to a grade rather than to the word titanium.
There is no single density for titanium
Commercially pure and alloyed titanium do not weigh the same, and the difference is settled by the grade on the order. These are the figures the Beiyu Titanium weight calculator runs on.
| Grade | Density (g/cm³) | Relative to Grade 2 |
|---|---|---|
| Grade 1, 2, 7 and 12 | 4.51 | Reference |
| Grade 9 (Ti-3Al-2.5V) | 4.48 | 0.7 per cent lighter |
| Grade 5 and Grade 23 (Ti-6Al-4V and ELI) | 4.43 | 1.8 per cent lighter |
The spread between grades is small enough that it never decides a grade choice on its own. It is large enough to matter when someone is reconciling a calculated weight against a delivered one, which is the situation where the question usually comes up in practice.
What that looks like as a part
Density is an abstraction until it is a size. The table below is round bar, kilograms per metre, calculated from the densities above using the cross-sectional area of the bar. The stainless column uses the figure of about 8.0 g/cm³ that our comparison pages use for stainless steel.
| Diameter | Grade 2 at 4.51 | Grade 5 at 4.43 | Stainless at about 8.0 |
|---|---|---|---|
| 10 mm | 0.35 kg/m | 0.35 kg/m | 0.63 kg/m |
| 16 mm | 0.91 kg/m | 0.89 kg/m | 1.61 kg/m |
| 20 mm | 1.42 kg/m | 1.39 kg/m | 2.51 kg/m |
| 25 mm | 2.21 kg/m | 2.17 kg/m | 3.93 kg/m |
| 32 mm | 3.63 kg/m | 3.56 kg/m | 6.43 kg/m |
| 40 mm | 5.67 kg/m | 5.57 kg/m | 10.05 kg/m |
| 50 mm | 8.86 kg/m | 8.70 kg/m | 15.71 kg/m |
For Grade 2 the saving against stainless is about 44 per cent in every row, and for Grade 5 about 45, because it is a density ratio and the geometry cancels. Those are the numbers worth carrying: a Grade 2 part weighs roughly 44 per cent less than the same part in stainless, and roughly 67 per cent more than the same part in aluminium.
Titanium against the two metals it usually replaces
| Density (g/cm³) | Same part, relative mass | What it is chosen for | |
|---|---|---|---|
| Aluminium | about 2.7 | About 40 per cent lighter than titanium | Lowest mass where the load and the environment allow it |
| Titanium, Grade 2 | 4.51 | Reference | Corrosion resistance at moderate strength |
| Titanium, Grade 5 | 4.43 | 1.8 per cent lighter than Grade 2 | Load-carrying parts where mass costs money |
| Stainless steel | about 8.0 | About 77 per cent heavier than titanium | Price and ease of fabrication |
Those two percentages are where the confusion in this question usually starts. At 4.51 against 8.0, titanium is 43.6 per cent lighter than stainless and stainless is 77.4 per cent heavier than titanium, rounded on this page to 44 and 77. Same fact from opposite ends, and note that the two rounded figures are not each other’s inverse, so they cannot be substituted for one another in a sentence.
Why density is usually the wrong question
Very few parts are selected on mass alone. What decides a substitution is how much load the part carries for the mass it adds, and on that measure the ranking changes. Grade 5 titanium reaches about 895 MPa tensile against roughly 515 MPa for annealed 316 stainless, at a little over half the density. That ratio, rather than the density on its own, is what a rotating part or a mass-budgeted assembly is buying.
Against aluminium the same logic runs the other way from where the raw density puts it. Aluminium is lighter, but titanium carries far more absolute load for a given cross-section, so a titanium part can be thinner and still take more force. The two comparisons are worked through on the titanium against stainless steel and titanium against aluminium pages.
Calculated weight and delivered weight are not the same number
Every figure above is a calculated weight: nominal diameter, nominal density, perfect geometry. A delivered bar sits somewhere inside the diameter tolerance of the standard it was ordered to, and its mass moves with the square of the diameter, so a diameter at the top of tolerance carries more metal than the nominal figure, and that excess grows with the square of the diameter.
| Where it bites | What it looks like | What resolves it |
|---|---|---|
| Reconciling a delivery against a calculation | A delivery weighing more than the calculation reads as an error, when the standard explicitly allows it | Agree the weight basis, calculated or weighed, before the order |
| Design mass budgets | A calculated figure taken as exact leaves no allowance for the tolerance the material is supplied to | Budget against the tolerance band, not the nominal diameter |
Neither is a quality problem, and the standards say so in as many words. What surprises people is that the allowance runs in one direction only: it permits the delivered weight to come in over the calculation, and there is no matching under tolerance, because short weight is controlled by the dimensional tolerances instead.
| Standard and form | Permitted overweight against the calculated figure |
|---|---|
| ASTM B348, bar and billet | Up to 10 per cent over the theoretical weight, any ordered size, any finish |
| ASTM B265, sheet: five sheets or fewer, or an item estimated at 200 lb (91 kg) or less | Up to 10 per cent over the estimated weight |
| ASTM B265, sheet: more than five sheets and estimated at more than 200 lb | Up to 7.5 per cent over the estimated weight |
| ASTM B265, strip | Up to 10 per cent over the estimated weight |
Note the wording shifts between the two standards: B348 measures against theoretical weight and B265 against estimated weight. Note also that B265 sets no under tolerance on weight at all for sheet, and that where random or mill-size sheet is ordered on a square foot basis, the square footage shipped may exceed the quantity ordered by up to 5 per cent. These are the clauses to have in hand when a delivered weight is being questioned.
Common follow-up questions
Is titanium heavy to handle on the shop floor? Relative to the stainless or steel stock it usually replaces, no, and fabricators notice it immediately in handling and fixturing. Relative to aluminium it reads as dense. The practical point is that the question has no answer until a comparison metal is attached to it.
Is titanium heavier than aluminium? Yes, by about 67 per cent, at 4.51 against about 2.7 g/cm³. Aluminium wins on raw weight and titanium wins once the part has to carry load or resist corrosion.
Is titanium lighter than steel? Yes, against both kinds, and the two savings differ enough to be worth separating. Against stainless at about 8.0 g/cm³, a Grade 2 part is roughly 44 per cent lighter. Against carbon steel at about 7.85, the saving is a little over 40 per cent. Quoting the stainless figure for a carbon steel substitution overstates the saving.
Why does titanium feel heavier than people expect? Because the comparison people make in their hand is usually with aluminium, not with steel. A titanium item picked up cold reads as substantial next to an aluminium one of the same size, and the reputation for lightness comes from the steel comparison instead.
Which titanium grade is the lightest? Of the grades on this page, Grade 5 and Grade 23 at 4.43, but the difference from commercially pure is 1.8 per cent and no part should be specified on that basis. Choose the grade on strength and corrosion, then take the density that comes with it.
Does the mill certificate state the density? No. ASTM B348 requires the report to certify that the material was manufactured, inspected, sampled and tested to the specification, and to give the results of chemical analysis, tensile and the other required tests. Size appears as the description of the item, not as a measured result, and density appears nowhere: it is a property of the grade rather than of the heat. So a weight figure is calculated from the grade’s published density and checked against the dimensional tolerance, not read off the certificate.
Specification detail with sources
The densities of 4.51 g/cm³ for Grades 1, 2, 7 and 12, 4.48 for Grade 9 and 4.43 for Grade 5 and Grade 23 are the constants the Beiyu Titanium weight calculator runs on, and that calculator is the single source used throughout this page. Where an individual grade data sheet states a density it carries the same figure: the Grade 2 and Grade 7 sheets give 4.51 and the Grade 5 and Grade 23 sheets give 4.43, the two alloy sheets adding that mill sheets quote a range of 4.42 to 4.47 and citing the ASM Handbook. The Grade 1, Grade 9 and Grade 12 sheets state no density, so for those grades the calculator is the only figure on the site. The kilograms per metre figures are arithmetic from those densities and the circular cross-sectional area of the stated diameter, not separately published values. The comparison figure of about 8.0 g/cm³ for stainless steel and the resulting saving of roughly 44 per cent are the figures carried on our titanium against stainless steel page, and the figure of about 2.7 g/cm³ for aluminium is the one carried on the titanium against aluminium page. The tensile figures of about 895 MPa for Grade 5 and roughly 515 MPa for annealed 316 stainless are also from the stainless comparison page. The overweight allowances are the weight clauses of the two specifications: ASTM B348 states that the shipping weight of any item of an ordered size in any finish may exceed the theoretical weight by as much as 10 per cent, while ASTM B265 sets its sheet allowance at 10 per cent over estimated weight for five sheets or fewer or items of 200 lb (91 kg) or less and 7.5 per cent above that, records that there is no under tolerance in weight for sheet because under weight is controlled by the permissible thickness variations, allows square footage on random or mill-size sheet to exceed the order by up to 5 per cent, and sets the strip allowance at 10 per cent over estimated weight. The certificate content described above is ASTM B348’s certification clause.
Getting the weight right on an order
If mass is part of the decision, the grade, the form and the finished dimensions settle it and the calculation follows from there. Send the grade, the product form, the nominal dimensions and the length or quantity, and say which weight basis your own figure was worked out on, because a calculated weight and a delivered weight are not the same number and the overweight allowances above sit between them. 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.