Steel GX5NiS36-A (Solution annealed)
Temper
EN 1.3963
Softest and most ductile state; used when maximum machining ease and a homogeneous, low-scatter expansion coefficient are wanted before final stabilizing.
Values for the A condition
Other GX5NiS36 tempers and conditions
GX5NiS36 is listed in 5 conditions; see the grade overview at GX5NiS36.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AThis page Solution annealed | Softest and most ductile state; used when maximum machining ease and a homogeneous, low-scatter expansion coefficient are wanted before final stabilizing. | 180 | 400 | 15 | 125 HB | 2.2 % IACS |
SRDefault Stress relieved | Standard delivery condition: removes casting residual stress so parts hold shape through rough and finish machining. | 200 | 420 | 12 | 135 HB | 2.1 % IACS |
Hot isostatic pressed | Optional densification for pressure-tight or fatigue-loaded castings; closes microporosity and raises ductility, at extra cost. | 210 | 450 | 18 | 140 HB | 2.2 % IACS |
As fabricated | Cheapest condition for rough or non-critical low-expansion castings that will be stress-relieved after machining anyway. | 215 | 430 | 10 | 145 HB | 2.1 % IACS |
Dimensionally stabilized | Three-step Invar stabilizing cycle for metrology frames, gauges and optical benches where microstrain drift over years must be minimised. | 220 | 430 | 13 | 140 HB | 2.1 % IACS |
What is GX5NiS36-A?
GX5NiS36-A is GX5NiS36 in the A temper — softest and most ductile state; used when maximum machining ease and a homogeneous, low-scatter expansion coefficient are wanted before final stabilizing. GX5NiS36-A has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 99% of steel grades. Elongation at break is 15% and the elastic modulus is 141 GPa (20.5 Msi). GX5NiS36-A has a density of 8.1 g/cm³ (0.293 lb/in³), heavier than 97% of steel grades. It melts at 1,425°C (2,597 °F). SR is the default condition FabDigit quotes; A is available on request or by drawing note.
Advantages
- Good corrosion resistance — 32/100, better than 96% of steel grades
Limitations
- Low strength — 180 MPa (26.1 ksi), worse than 99% of steel grades
- Poor heat conductor — 11.8 W/m·K (6.82 BTU/hr·ft·°F), worse than 99% of steel grades
- High embodied carbon — 8.5 kg CO₂/kg, worse than 99% of steel grades
- Low stiffness — 141 GPa (20.5 Msi), worse than 98% of steel grades
- Low electrical conductivity — 2.2 % IACS, worse than 98% of steel grades
GX5NiS36-A properties
Typical room-temperature values for GX5NiS36-A; 23 are specific to this condition. Other listed values are GX5NiS36 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
GX5NiS36-A has a density of 8.1 g/cm³ (0.293 lb/in³), heavier than 97% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
GX5NiS36-A has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 99% of steel grades. Elongation at break is 15% and the elastic modulus is 141 GPa (20.5 Msi).
Thermal6
GX5NiS36-A is rated for continuous service to 200°C (392 °F). It conducts heat at 11.8 W/m·K (6.82 BTU/hr·ft·°F), worse than 99% of steel grades. Thermal expansion is 2.6 µm/m·K (1.44 µin/in·°F).
Electrical3
GX5NiS36-A conducts electricity at 2.2 % IACS, worse than 98% of steel grades.
Chemical & Environmental2
Corrosion resistance is poor (32/100), better than 96% of steel grades.
Sustainability4
Producing a kilogram of GX5NiS36-A takes about 110 MJ of energy and emits 8.5 kg of CO₂ — more than 99% of steel grades. Typical recycled content is 35%.
Manufacturability7
GX5NiS36-A's machinability is fair (42/100, worse than 73% of steel grades); weldability poor (28/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with GX5NiS36-A
Is GX5NiS36 easy to machine?
Best of the Invar family: run sharp positive-rake carbide at low speed (roughly 25–50 m/min) with heavy flood coolant; the MnS inclusions break chips and reduce the gummy built-up edge typical of Invar 36.
Can GX5NiS36 be welded?
Poor — sulfur strongly promotes solidification cracking; if unavoidable use matched low-S Invar filler, low heat input, preheat-free, and expect a HAZ with degraded expansion behaviour.
Can GX5NiS36 be formed, bent or molded?
A casting alloy only: sand or investment cast with generous risers because of the long freezing range; no meaningful cold formability.
What surface finishes work on GX5NiS36?
Not corrosion resistant — protect with oil, paint, electroless Ni or chrome plate; polished surfaces show sulfide pull-out, so lapping needs fine grit and patience.
GX5NiS36 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| CGX5 designation ≈ 0.05 % C | ≤ 0.07 | 0.05 |
| Si | ≤ 0.6 | 0.3 |
| Mnmust be sufficient to tie up S as MnS | 0.2 – 0.8 | 0.5 |
| P | ≤ 0.03 | 0.02 |
| Sdeliberate free-machining addition | 0.15 – 0.35 | 0.25 |
| Nicontrols the Invar minimum in CTE | 35 – 37 | 36 |
| Coresidual | ≤ 0.5 | — |
| Crresidual; raises CTE | ≤ 0.3 | — |
| Fe | balance | — |
GX5NiS36-A — frequently asked
What is GX5NiS36-A used for?
GX5NiS36-A is typically used for machined low-expansion tooling castings, precision jigs and fixtures and measurement standard castings. In short: best-machining cast Invar; free-machining Fe-36Ni casting; poor weldability.
What is the yield strength of GX5NiS36-A?
GX5NiS36-A has a typical yield strength of 180 MPa (26.1 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 99% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is GX5NiS36-A easy to machine?
Not especially — machinability is rated fair (42/100, worse than 73% of steel grades). Best of the Invar family: run sharp positive-rake carbide at low speed (roughly 25–50 m/min) with heavy flood coolant; the MnS inclusions break chips and reduce the gummy built-up edge typical of Invar 36.
Can GX5NiS36-A be welded?
Not readily — weldability is rated poor (28/100). Poor — sulfur strongly promotes solidification cracking; if unavoidable use matched low-S Invar filler, low heat input, preheat-free, and expect a HAZ with degraded expansion behaviour.
What surface finishes work on GX5NiS36-A?
Not corrosion resistant — protect with oil, paint, electroless Ni or chrome plate; polished surfaces show sulfide pull-out, so lapping needs fine grit and patience.
Can GX5NiS36-A be formed, bent or molded?
A casting alloy only: sand or investment cast with generous risers because of the long freezing range; no meaningful cold formability.
What is the maximum service temperature of GX5NiS36-A?
GX5NiS36-A is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between GX5NiS36-SR and GX5NiS36-A?
SR is the default condition — standard delivery condition: removes casting residual stress so parts hold shape through rough and finish machining. A: softest and most ductile state; used when maximum machining ease and a homogeneous, low-scatter expansion coefficient are wanted before final stabilizing. Yield strength is 200 MPa in SR versus 180 MPa in A.
Sources
- SEW 385 — Physikalisch bestimmte Eisenlegierungen (Fe-Ni low-expansion cast and wrought alloys) — Verein Deutscher Eisenhüttenleute (VDEh) (1993)
- DIN 17745 — Nickel-Eisen-Knetlegierungen mit vorgeschriebener Wärmeausdehnung — DIN (2002)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Low-Expansion Alloys) — ASM International (1990)
- Cast Invar / free-machining Fe-36Ni foundry alloy data — European low-expansion alloy foundries (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.