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Basic Temper Designations
F-as fabricated. Applies to the products of shaping
processes in which no special control over thermal conditions or
strain-hardening is employed. For wrought products, there are no
mechanical property limits.
O-annealed (wrought products only).
Applies to wrought products which are fully annealed to obtain the
lowest strength conditions.
H-strain-hardened (wrought products
only). Applies to products which have their strength increased by
strain-hardening, with or without supplementary thermal treatments
to produce some reduction in strength. The H is always followed
by two or more digits.
T-applies to products which are thermally
treated, with or without supplementary strain-hardening, to produce
stable tempers. The T is always followed by one or more digits.
The H and T tempers are further subdivided:
Subdivision of H Temper: Strain-Hardened
The first digit following the H indicates the specific combination
of basic operations, as follows:
H1-strain-hardened only. Applies
to the products which are strain-hardened to obtain the desired
strength without supplementary thermal treatment. The number following
this designation indicates the degree of strain-hardening.
H2-strain-hardened and partially
annealed. Applies to the products which are strain-hardened more
than the desired final amount and then reduced in strength to the
desired level by partial annealing. For alloys that age-soften at
room temperature, the H2 tempers have the same minimum ultimate
tensile strength as the corresponding H3 tempers. For other alloys,
the H2 tempers have the same minimum ultimate tensile strength as
the corresponding H1 tempers and slightly higher elongation. The
number following this designation indicates the degree of strain-hardening
remaining after the product has been partially annealed.
H3-strain-hardened and stabalized.
Applies to products which are strain-hardened and whose mechanical
properties are stabilized by a low temperature thermal treatment
which results in slightly lowered tensile strength and improved
ductility. This designation is applicable only to those alloys which,
unless stabilized, gradually age-soften at room temperature. The
number following this designation indicates the degree of strain-hardening
before the stabilization treatment.
The third digit, when used, indicates a variation
of a two digit temper. It is used when the degree of control of
temper or the mechanical properties are different from but close
to those for the two-digit H temper designation to which it is added,
or when some other characteristic is significantly affected.
The following three-digit H temper designations have
been assigned for wrought products in all alloys:
H111 - Applies to products which
are strainhardened less than the amount required for a controlled
H11 temper.
H112 - Applies to products which
acquire some temper from shaping processes not having special control
over the amount of strain-hardening or thermal treatment, but for
which there are mechanical property limits.
The following three-digit H temper designations have
been assigned for wrought products in alloys containing over a nominal
4% magnesium.
H311 - Applies to products which
are strain-hardened less than the amount required for a controlled
H31 temper.
H321 - Applies to products which
are strain-hardened less than the amount required for a controlled
H32 temper.
H323 & H343 - Applies to products
which are specially fabricated to have acceptable resistance to
stress corrosion cracking.
Subdivisions of T Temper: Thermally Treated
Numerals 1 through 10 following the T indicate specific
sequences of basic treatments, as follows:
T1-Applies to products for which
the rate of cooling from an elevated temperature shaping process,
such as casting or extrusion, is such that their strength is increased
by room temperature aging.
T2-Applies to cast products which
are annealed to improve ductility and dimensional stability.
T3-Applies to products which are
cold worked to improve strength, or in which the effect of cold
work in flattening or straightening may not be recognized in mechanical
property limits.
T4-Applies to products which are
not cold worked after solution heat-treatment, or in which the effect
of cold work in flattening or straightening may not be recognized
in mechanical property limits.
T5-Applies to products which are
cooled from an elevated temperature shaping process, such as casting
o r extrusion, and then artificially aged to improve mechanical
properties or dimensional stability or both.
T6-Applies to products which are
not cold worked after solution heat-treatment, or in which the effect
of cold work in flattening or strengthening may not be recognized
in mechanical property limits.
T7-Applies to products which are
stabilized to carry them beyond the point of maximum strength to
provide control of some special characteristics.
T8-Applies to products which are
cold worked to improve strength, or in which the effect of cold
work in flattening or straightening is recognized in mechanical
property limits.
T9-Applies to products which are
cold worked to improve strength.
T10-Applies to products which are
artificially aged after cooling from an elevated temperature shaping
process, such as casting or extrusion, and then cold worked to further
improve strength.
Additional Digits for T Tempers
The following additional digits have been assigned
for stress-relieved tempers or wrought products:
TX51-Applies to the following products
when stretched the indicated amounts after solution heat-treatment.
Plate - 1½ to 3% permanent
set. Rod, bar, shapes, extruded tube - 1 to 3% permanent set. Applies
directly to plate and rolled or cold finished rod and bar. These
products receive no further straightening after stretching. Applies
to extruded rod, bar, shapes and tube when designated as follows:
TX510-Products that receive no further
straightening after stretching.
TX511-Products that may receive minor
straightening after stretching to comply with standard tolerances.
TX52-Applies to products which are
stress-relieved by compressing after solution heat-treatment, to
produce a permanent set of 1 to 5%.
The following temper designations have been assigned
for variations of T4 and T6 tempers of wrought products:
T-42-solution heat-treated from the
O or F temper by the user, or by the producer to demonstrate response
to heat-treatment, and naturally aged to a substantially stable
condition.
T-62-solution heated treated from
the O or F temper by the user, or by the producer to demonstrate
response to heat-treatment, and artificially aged. Apply when available
data indicate that any characteristic such as corrosion resistance,
fatigue, or a mechanical property is significantly different from
that for the T4 to T6 temper, respectively.
The solution heat-treatment practice used is the same
as that for the T4 temper of the same alloy and product, and the
artificial aging practice used is usually the same as that for the
T6 temper of the same alloy and product. Material which is formed
or cold worked by the user prior to solution heat-treatment may
not attain the mechanical properties applicable to these tempers.
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