This designation applies to products which are not cold worked after cooling from an elevated temperature shaping process, or in which the effect of cold work in flattening or straighten
F – as fabricated
This designation refers to products created through shaping processes that do not involve specific control over thermal conditions or strain hardening For this temper, there are no defined limits on mechanical properties.
O - Annealed
This designation applies to products which are annealed to obtain the lowest strength temper The O may be followed by a digit other than zero 1
H – Strain-hardened
The designation "H" refers to products that undergo cold work after annealing or hot forming, or a mix of cold work and partial annealing to achieve desired mechanical properties This designation is followed by at least two digits: the first digit represents the specific combination of operations, while the second indicates the degree of strain hardening A third digit may be added to denote variations in mechanical properties or other characteristics from the original two-digit H temper.
1 Products achieving the required annealed properties after hot forming processes may be designated as O temper.
W – Solution heat-treated
This designation refers to an unstable temper, applicable solely to alloys that undergo spontaneous aging at room temperature following solution heat treatment It is specifically relevant when the duration of natural aging is specified, such as W 1/2 h.
T - Thermally treated to produce stable tempers other than F, O or H (for heat-treatable
This designation refers to thermally treated products that may also undergo additional strain-hardening to achieve stable tempers The letter "T" is succeeded by one or more digits that specify the exact sequence of these treatments.
6 Subdivision of O (annealed) temper designations
O1 – High temperature annealed and slow cooled
This designation refers to wrought products that undergo thermal treatment at specific temperatures and times, similar to those used in solution heat treatment, followed by slow cooling to room temperature This process is essential for achieving the desired ultrasonic response and ensuring dimensional stability It is particularly relevant for products that will be machined by the user before the solution heat treatment Note that mechanical property limits are not defined.
O 2 – Thermo-mechanically processed
This designation refers to wrought products that undergo a specific thermo-mechanical treatment, intended for items that will be super-plastically formed before the user performs a solution heat treatment.
O3 – Homogenized
This designation refers to continuously cast drawing stock or strip that undergoes a high-temperature soaking treatment This process aims to eliminate or reduce segregations, ultimately enhancing the material's formability and its response to solution heat treatment.
7 Subdivision of H (strain-hardened) temper designations
Subdivisions are made according to the basic operations described in 5.3 and the final degree of strain hardening, as follows:
The first digit following the letter H indicates the specific combination of basic operations as follows:
These designations apply to products which are strain-hardened to obtain the desired strength without supplementary thermal treatment
— H2x Strain-hardened and partially annealed
Products designated with H2x tempers are strain-hardened beyond the intended final strength and then partially annealed to achieve the desired strength level For alloys that experience age-softening at room temperature, H2x tempers maintain the same minimum ultimate tensile strength as their H3x counterparts In contrast, for other alloys, H2x tempers exhibit the same minimum ultimate tensile strength as H1x tempers, along with slightly improved elongation properties.
Products that are strain-hardened and have stabilized mechanical properties through low temperature thermal treatment or heat from fabrication are designated accordingly This stabilization process typically enhances ductility and is relevant only for alloys that would otherwise experience gradual age-softening at room temperature.
— H4x Strain-hardened and lacquered or painted
These designations apply to products which are strain-hardened and which may be subjected to some partial annealing during the thermal curing which follows the painting or lacquering operation
The second digit following the letter H indicates the final degree of strain hardening, as identified by the minimum value of the ultimate tensile strength
The numeral 8 designates the hardest tempers typically produced, with the minimum tensile strength of tempers Hx8 derived from Table 1, which is based on the alloy's minimum tensile strength in the annealed temper.
Tempers between O (annealed) and Hx8 are classified using numerals 1 to 7 Numeral 2 represents tempers with an ultimate tensile strength that is roughly halfway between the O temper and the Hx4 temper Numeral 4 indicates tempers whose ultimate tensile strength is approximately in the middle of the O temper and the Hx8 temper Numeral 6 corresponds to tempers with an ultimate tensile strength that lies between the Hx4 and Hx8 tempers Additionally, numerals 1, 3, 5, and 7 denote tempers that are intermediate between the aforementioned classifications.
— Numeral 9 designates tempers whose ultimate tensile strength exceeds that of the Hx8 temper by
— The ultimate tensile strength of intermediate tempers, determined as described above, when not ending in 0 or 5, shall be rounded to the next higher 0 or 5
Table 1 — Determination of Hx8 minimum tensile strength
Minimum tensile strength in annealed temper
Increase in tensile strength to Hx8 temper
The third digit in a temper designation signifies a variation of a two-digit temper It is applied when the control degree of temper or mechanical properties, or both, are similar yet distinct from the corresponding two-digit H temper designation, or when another characteristic is notably influenced.
The following three digit H temper designations have been assigned:
Hx11 refers to products that experience significant strain-hardening after the final anneal, preventing them from being classified as annealed However, the level of strain hardening is not enough to meet the criteria for Hx1 classification.
H112 refers to products that may experience strain hardening due to processing at elevated temperatures or through a small degree of cold work, and it is associated with specific mechanical property limits.
— H116: applies to products, made of those alloys of the 5xxx group in which the magnesium content is
Products with a nominal strength of 3% or more are strain hardened during the final operation to achieve stable tensile property limits and specified corrosion resistance levels, as determined by accelerated corrosion tests These tests encompass inter-granular and exfoliation assessments This temper is appropriate for continuous service at temperatures not exceeding 65 °C.
— H321: applies to products, made of those alloys of the 5xxx group in which the magnesium content is
Products with a nominal strength of 3% or higher are thermally stabilized during the final operation to achieve specified tensile property limits and corrosion resistance levels, as determined by accelerated corrosion tests, including inter-granular and exfoliation tests This temper is ideal for continuous service at temperatures not exceeding 65 °C.
Products made from 5xxx series alloys, with a nominal magnesium content of 3% or more, undergo strain hardening to achieve stable tensile properties These products are designed to meet specific corrosion resistance levels in accelerated tests following a thermal treatment that enhances their performance in ambient conditions This temper is appropriate for continuous use at temperatures not exceeding 65 °C, and corrosion tests include inter-granular and exfoliation assessments.
— H131: applies to products, made of those alloys of the 5xxx group in which the magnesium content is
3 % nominal or more These products are strain hardened to specified tensile property limits, and to meet specified levels of corrosion resistance and ballistic performance
Hxx4 designates patterned or embossed sheets and strips made from the corresponding Hxx temper, with potential deviations in mechanical properties post-embossing or engraving H114 is applicable to products made from O, Hx1, H111, or H112 tempers For instance, an embossed sheet created from an H42 temper is labeled as H424.
— Hxx5: apply to welded tube Depending on alloy and geometry of the tube, the mechanical property limits may differ from those of the corresponding Hxx temper for strip
Additional digits may be utilized to identify variations of the basic temper H, with specific allocations for alloys as needed.
8 Subdivision of T (thermally treated to produce stable tempers other than F, O or H) temper designations
First digit after T
The first digit following the letter T is used to identify the specific sequences of basic treatments Numerals 1 to 10 have been assigned as follows 3 :
— T1: cooled from an elevated temperature shaping process and naturally aged to a substantially stable condition
This designation refers to products that have not undergone cold working after being shaped at high temperatures, or where the impact of cold work on flattening or straightening is not evident in their mechanical properties.
— T2: Cooled from an elevated temperature shaping process, cold worked and naturally aged to a substantially stable condition
This designation refers to products that undergo cold working to enhance strength following solution heat treatment, or where the impact of cold work on flattening or straightening is acknowledged in the limits of mechanical properties.
3 A period of natural ageing at room temperature may occur between or after the operations listed for T tempers Control of this period is exercised when it is metallurgically important
— T3: Solution heat-treated 4 , cold worked and naturally aged to a stable condition
This designation refers to products that undergo cold working to enhance strength following solution heat treatment, or where the impact of cold work on flattening or straightening is acknowledged in the limits of mechanical properties.
— T4: Solution heat-treated 4 and naturally aged to a substantially stable condition
This designation refers to products that have not undergone cold working following solution heat-treatment, or where the impact of cold work during flattening or straightening is not evident in the mechanical property limits.
— T5: Cooled from an elevated temperature shaping process and then artificially aged
This designation refers to products that have not undergone cold working after being cooled from a high-temperature shaping process, or where the impact of cold work during flattening or straightening is not reflected in the mechanical property limits.
— T6: Solution heat treated 4 and then artificially aged
This designation refers to products that have not undergone cold working following solution heat-treatment, or where the impact of cold work during flattening or straightening is not evident in the mechanical property limits.
— T7: Solution heat treated 4 and over-aged/stabilized
This designation refers to products that undergo artificial aging following solution heat treatment, allowing them to exceed their maximum strength This process is implemented to control important characteristics beyond just mechanical properties.
— T8: Solution heat-treated 4 , cold worked and then artificially aged
This designation refers to products that undergo cold working to enhance their strength, or where the impact of cold work on flattening or straightening is acknowledged in the limits of their mechanical properties.
— T9: Solution heat-treated 4 , artificially aged which are then cold worked
This designation applies to products which are cold worked to improve strength
— T10: Cooled from an elevated temperature shaping process, cold worked and artificially aged
This designation refers to products that undergo cold working after being cooled from a high-temperature shaping process, or where the impact of cold work during flattening or straightening is acknowledged in the limits of mechanical properties.
The above definitions are summarized in Table 2
Alloys from the 6000 or 7000 series can achieve the same mechanical properties whether they undergo furnace solution heat treatment or are rapidly cooled from an elevated temperature shaping process When permitted by material specifications or the purchaser, temper designations such as T3, T4, T6, T7, T8, and T9 can be applied to either process It is essential that the process is controlled to meet the specified mechanical properties and any additional requirements, such as corrosion resistance.
5 The test method and limit used to evaluate material to this characteristic are specified at the time of the temper definition
Table 2 — Summary of processing for achieving T tempers
Ageing Cold worked Cooled from shaping process Furnace solution heat-treated a
Yes - after ageing - T9 a See footnote 4 to text in 8.1
Additional digits added to designations T1 to T10
Additional digits, starting with a non-zero number, can be appended to designations T1 to T10 to signify a variation in treatment that notably changes the product's characteristics compared to the basic treatment These digits may pertain to one or more specific aspects of the treatment.
— The solution heat treatment and/or the precipitation heat treatment;
— The amount of cold work after solution heat treatment;
These additional digits may be assigned and standardized as described in Clause 1 and in accordance with 8.3 and 8.4
Variations in treatment that do not alter the characteristics of the product are considered alternative treatments for which additional digits are not assigned.
Assigned additional digits for stress-relieved T tempers
Stress-relieved by stretching
Tx51 or Txx51 is applicable to various forms of metal products, including plate, sheet, and rolled or cold finished rod and bar, as well as hand or ring forgings and rolled rings These products undergo a stretching process after solution heat-treatment or cooling from an elevated temperature shaping process, without any additional straightening The permanent set (deformation) for each product type varies: plates experience a permanent set of 1.5% to 3%, sheets have a set of 0.5% to 3%, rolled or cold finished rods and bars show a set of 1% to 3%, and hand or ring forgings and rolled rings can have a permanent set ranging from 1% to 5%.
The Tx510 or Txx510 specification is applicable to extruded rod, bar, profiles, and tube, as well as drawn tube, following specific stretching after solution heat treatment or cooling from a high-temperature shaping process Notably, these products do not undergo any additional straightening post-stretching For extruded rod, bar, profiles, and tube, the permanent set ranges from 1% to 3%, while for drawn tube, it is between 0.5% and 3%.
Tx511 or Txx511 is applicable to extruded rod, bar, profiles, and tube, as well as drawn tube, when subjected to specified stretching after solution heat treatment or cooling from a high-temperature shaping process These products may undergo minor straightening to meet standard tolerances, with extruded rod, bar, profiles, and tube allowing for a permanent set of 1% to 3%, while drawn tube permits a permanent set of 0.5% to 3%.
Stress-relieved by compressing
Tx52, also known as Txx52, refers to products that undergo stress relief through compression following solution heat treatment or cooling from a high-temperature shaping process, resulting in a permanent set ranging from 1% to 5%.
Stress-relieved by combined stretching and compressing
— Tx54 or Txx54 applies to die forgings which are stress-relieved by restriking cold in the finish die.
Assigned additional digits for stress-relieved W tempers
The same digits as those defined in 8.3.1, 8.3.2 and 8.3.3 may be added to the designation W (e.g.: W51; W510; W511; W52; W54) to indicate unstable solution heat-treated and stress-relieved tempers.
Assigned additional digits for variations of T7 type tempers
These designations apply to products which are artificially overaged in order to:
— improve a property such as stress corrosion resistance, fracture toughness, exfoliation corrosion resistance;
— or to obtain a good compromise between the above properties and the tensile strength lt is recommended that the following guidelines be applied when standardizing new alloy-temper-product combinations:
— T79 very limited overaging to achieve improved corrosion resistance compared to the T6 temper and limited strength reduction compared to the T6 temper
— T78: overageing to achieve optimum intercrystalline corrosion resistance This temper specifically applies to 6000 series alloys
— T77: aged condition to provide strengths at or near to the T6 temper and corrosion resistance similar to the T76 temper
— T76 limited overaging to achieve moderate corrosion resistance with some reduction in strength The T76 temper has lower strength and better corrosion resistance than the T79 temper
— T74 moderately overaged to achieve good corrosion resistance with a greater reduction in strength compared to the T76 temper T74 temper strength and corrosion resistance properties are between those of the T73 and T76 tempers
— T73 fully overaged to achieve the best corrosion resistance of the T7x tempers, with a greater reduction in strength compared to the T74 temper
The evolution of material properties from temper T79 to T73, is summarized in Figure 1.
Demonstration of response to heat treatment
Temper designations for producer/supplier — Laboratory demonstration of response to
The temper designations for wrought product test materials that have undergone furnace heat treatment from annealed (O, O1, etc.) or F temper include: a) T42, which is solution heat-treated from annealed or F temper and naturally aged to a stable condition; b) T62, which is solution heat-treated from annealed or F temper and artificially aged; and c) T7x2, which is solution heat-treated from annealed or F temper and artificially overaged to achieve the required mechanical properties and corrosion resistance of the applicable T7x temper.
Temper designations for producer/supplier — Demonstration of response to temper
Temper designation Tx2 or Txx2 indicates wrought product test material that has undergone furnace heat treatment for demonstrating temper conversion capabilities If the purchaser requests capability demonstrations from T temper, the seller must note "Capability Demonstration" next to the specified and ending tempers.
— T3 to -T82 capability demonstration for response to ageing”;
— T4 to -T62 capability demonstration for response to ageing”;
— T4 to -T762 capability demonstration for response to overageing”;
— T6 to -T732 capability demonstration for response to overageing”;
— T351 to -T42 capability demonstration for response to re-solution heat-treating”.
Temper designations for purchaser/user heat treatment
The temper designation Tx2 or Txx2 must be used for wrought products that are heat treated by the purchaser or user, following the relevant heat treatment specifications to attain the desired properties of the final temper.
A summary of tempers used in the European Standards is shown in Table 3
NOTE This is a generalized representation Actual magnitude and combination of properties vary for individual alloys
Figure 1 — Summary of generalized relationships for some T7X temper properties
Table 3 — Summary of used tempers in European Standards
F as fabricated (no mechanical property limits specified)
Products that achieve the necessary annealed properties after hot forming processes are classified as 0 temper Additionally, O1 refers to materials that undergo thermal treatment at similar temperatures and durations as solution treatment, followed by a slow cooling process to room temperature, previously known as T41.
O2 thermomechanically processed to enhance formability, such as required for super- plastic forming (SPF)
H18 strain-hardened- 4/4 hard (fully hardened)
Hxx4 apply to embossed or patterned sheet or strip, fabricated from the corresponding Hxx temper Hxx5 strain-hardened- apply to welded tubes
H111 temper indicates that the aluminum has been annealed and slightly strain-hardened through processes like stretching or leveling H112 refers to aluminum that has undergone slight strain hardening due to elevated temperature working or limited cold work, with specified mechanical property limits H116 is specific to aluminum-magnesium alloys with a nominal magnesium content of 3% or more, which are strain-hardened during the final operation to achieve stable tensile properties and meet corrosion resistance standards in accelerated tests, including inter-granular and exfoliation tests This temper is suitable for continuous service at temperatures not exceeding specified limits.
H1X8 pertains to products made from 5xxx series alloys with a nominal magnesium content of 3% or higher These products undergo strain hardening during the final operation to achieve stable tensile properties and are designed to meet specific corrosion resistance levels in accelerated tests A thermal treatment is applied to enhance corrosion performance under ambient conditions, making this temper suitable for continuous service at temperatures up to 65 °C Corrosion testing includes inter-granular and exfoliation assessments.
H131 is designated for products made from 5xxx group alloys with a nominal magnesium content of 3% or higher These products undergo strain hardening to achieve specific tensile property limits, ensuring they meet required standards for corrosion resistance and ballistic performance.
H22 strain-hardened and partially annealed - 1/4 hard
H24 strain-hardened and partially annealed - 1/2 hard
H26 strain-hardened and partially annealed - 3/4 hard
H28 strain-hardened and partially annealed - 4/4 hard (fully hardened)
H32 strain-hardened and stabilized - 1/4 hard
H34 strain-hardened and stabilized - 1/2 hard
H36 strain-hardened and stabilized - 3/4 hard
H321 is applicable to products made from 5xxx group alloys with a nominal magnesium content of 3% or higher These products undergo thermal stabilization during the final operation to achieve specified stable tensile properties and corrosion resistance levels, verified through accelerated corrosion tests, including inter-granular and exfoliation tests This temper is ideal for continuous service at temperatures not exceeding 65 °C.
H38 strain-hardened and stabilized - 4/4 hard (fully hardened)
H42 strain-hardened and painted or lacquered - 1/4 hard
H44 strain-hardened and painted or lacquered - 1/2 hard
H46 strain-hardened and painted or lacquered - 3/4 hard
H48 strain-hardened and painted or lacquered - 4/4 hard (fully hardened)
W solution heat-treated products are in an unstable temper and may undergo a specified period of natural aging (W2h, etc.) W51 solution heat-treated products are also in an unstable temper and are stress-relieved by applying a controlled amount of stretching, resulting in a permanent set ranging from 0.5% to 3% for sheets, 1.5% to 3% for plates, 1% to 3% for rolled or cold-finished rods and bars, and 1% to 5% for hand or ring forgings and rolled rings After stretching, these products do not receive any further straightening.
The W510 solution is heat-treated to an unstable temper and stress-relieved by applying a controlled permanent set, ranging from 1% to 3% for extruded rod, bar, shapes, and tube, and 0.5% to 3% for drawn tube After this stretching process, the products do not undergo any additional straightening.
The W511 alloy is similar to W510, with the exception that minor straightening is permitted after stretching to meet standard tolerances Additionally, W52 undergoes solution heat treatment (unstable temper) and is stress-relieved through compression, resulting in a permanent set ranging from 1% to 5%.
W54 solution heat-treated (unstable temper) and stress-relieved by restriking cold in the finish die (die forging) T1 cooled from an elevated temperature shaping process and naturally aged
T2 cooled from an elevated temperature shaping process, cold worked and naturally aged
T3 solution heat-treated, cold worked and naturally aged
T31 solution heat-treated, cold worked approximately 1 % and naturally aged
T34 Solution heat-treated, cold worked (permanent set 3,0 to 4,5 %) and naturally aged
T351 solution heat-treated, stress-relieved by stretching a controlled amount (permanent set
The percentage composition for various metal products is as follows: 0.5% to 3% for sheets, 1.5% to 3% for plates, 1% to 3% for rolled or cold-finished rods and bars, and 1% to 5% for hand or ring forging and rolled rings Additionally, these products are naturally aged and do not undergo any further straightening after the stretching process.
T3510 solution heat-treated, stress-relieved by stretching a controlled amount (permanent set
1 %, to 3 % for extruded rod, bar, shapes and tube, 0,5 % to 3 % for drawn tube) and naturally aged The products receive no further straightening after stretching
The T3511 alloy is similar to T3510, with the addition of minor straightening permitted after stretching to meet dimensional tolerances The T352 alloy undergoes solution heat treatment and is stress-relieved through compression, resulting in a permanent set of 1% to 5%, followed by natural aging The T354 alloy is also solution heat-treated and stress-relieved, but it is restruck cold in the finish die before natural aging Lastly, the T36 alloy is solution heat-treated, cold worked by approximately 6%, and then naturally aged.
T37 solution heat-treated, cold worked approximately 7 % and naturally aged
The T39 alloy undergoes solution heat treatment and is subsequently cold worked to attain the desired mechanical properties, with cold working possible before or after natural aging In contrast, the T4 alloy is solution heat-treated and then naturally aged.
The T42 solution is heat-treated and naturally aged, suitable for testing materials that have been heat-treated from either annealed or F temper, as well as products heat-treated from any temper by the user In contrast, the T451 solution undergoes heat treatment and is stress-relieved through a controlled stretching process, resulting in a permanent set.
The percentage ranges for various products are as follows: 0.5% to 3% for sheets, 1.5% to 3% for plates, 1% to 3% for rolled or cold-finished rods and bars, and 1% to 5% for hand or ring forging and rolled rings These products are naturally aged and do not undergo any additional straightening after the stretching process.
T4510 solution heat-treated, stress-relieved by stretching a controlled amount (permanent set
1 % to 3 % for extruded rod, bar, shapes and tube, 0,5 % to 3 % for drawn tube) and naturally aged The products receive no further straightening after stretching
The T4511 alloy is similar to T4510, with the addition of allowing minor straightening post-stretching to meet dimensional tolerances The T452 alloy undergoes solution heat treatment and is stress-relieved through compression, resulting in a permanent set of 1% to 5%, followed by natural aging In contrast, the T454 alloy is also solution heat-treated and stress-relieved, but it is processed by restriking cold in the finish die before being naturally aged.
T5 cooled from an elevated temperature shaping process and then artificially aged
Numeral 1 as a second digit after T
The numeral 1 signifies a solution heat-treatment conducted at a temperature lower than the standard, a restricted quenching rate, a controlled degree of cold work, or artificial aging under underageing conditions.
Wrought products are designed to enhance specific properties such as ductility, formability, reduced deformation, and fracture toughness, surpassing the characteristics found in the corresponding Tx conditions.
Numerals 1 and 3 to 9 as a second digit after T3, T8 or T9
This digit may be used to indicate increasing amounts of cold work after solution heat-treatment or after artificial ageing as applicable
NOTE For some particular T8 type tempers, the second digit may be used to indicate different degrees of underageing.
Numerals 1 and 3 to 5 as a second digit after T5 or T6
This digit may be used to indicate different degrees of underageing.
Numeral 6 as a second digit after T5 or T6
This digit may be used to indicate a level of mechanical properties, respectively higher than T5 or T6, obtained through special control of the process.
Summary of possible uses of a second digit after T
Table A.1 summarizes the various uses (recommended or assigned) of the second digit after the letter T
Table A.1 — Various uses of the second digit after letter T
Second digit Relevant process and subclause
Figure A.1 illustrates the tensile strength of 7000 series alloys in relation to the ageing conditions of T6 and T7 tempers, with the T77 temper omitted for clarity.
Temper T78 only applies to 6000 series alloys
Figure A.1 — Relative positions of the variations of T6 and T7 tempers
[1] EN 12258-1:2012, Aluminium and aluminium alloys - Terms and definitions - Part 1: General terms