Steel SK5 vs T7A
Steel · grade comparison
Steel SK5 and T7A are both steel grades. SK5 is the stronger of the two: yield strength 400 MPa (58 ksi) against 380 MPa (55.1 ksi) for T7A, about 5% more; tensile strength follows at 710 MPa (103 ksi) vs 660 MPa (95.7 ksi). In exchange, T7A is the more ductile: elongation 22% versus 12% for SK5, and SK5 is harder (200 HB vs 180 HB). SK5 runs hotter in service (350°C vs 300°C continuous). On the shop floor, T7A machines more easily (good vs fair) and T7A sits in a lower cost tier (budget, $) than SK5 (standard, $$).
SK5Choose it when strength drives the design, or when the part sees heat.
T7AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
SK5 vs T7A: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Specific Heat Capacity
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 48 W/m·K27.7 BTU/hr·ft·°F · Thermal Expansion (CTE, 20–100 °C) 11.5 µm/m·K6.4 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 9.5 % IACS · Electrical Resistivity 1.8×10⁻⁷ Ω·m7.09 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 10 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Same in both: Castability 30 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Typical Recycled Content
Same in both: Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
Strength versus weight
Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | SK5 | T7A |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Default condition | HR | — |
| Relative cost | $$ Standard | $ Budget |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 1.6 µm | — |
| AlCrN | Yes | — |
| AlTiN | Yes | — |
| Black Oxide | Yes | — |
| CVD Al2O3 | Yes | — |
| CVD TiCN | Yes | — |
| CVD TiN | Yes | — |
| Cerakote | Yes | — |
| Chrome Plating | Yes | — |
| CrN | Yes | — |
| DLC | Yes | — |
| E-Coating | Yes | — |
| HVOF Coating | Yes | — |
| Hot-Dip Galvanizing | Yes | — |
| MoS2 | Yes | — |
| Multilayer CVD | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Painting | Yes | — |
They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
SK5 vs T7A — frequently asked
Is SK5 stronger than T7A?
Yes. SK5 has a typical yield strength of 400 MPa (58 ksi) against 380 MPa (55.1 ksi) for T7A — about 5% more. Tensile strength is 710 MPa (103 ksi) vs 660 MPa (95.7 ksi).
Which is cheaper, SK5 or T7A?
T7A is the lower-cost material: it sits in the budget tier ($) while SK5 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, SK5 or T7A?
T7A. Its machinability rates good (62/100) against fair (36/100) for SK5.
Ready to make it?
Upload a CAD file and FabDigit prices the part in SK5 and T7A side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.