Steel SHY685-NS vs SHY685-QT
Steel · SHY685 temper comparison
SHY685-NS and SHY685-QT are two conditions of the same steel grade, SHY685: NS (SHY685NS) versus QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. Both yield at about 720 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (SHY685NS versus quenched and tempered). SHY685-QT is harder — 26 HRC against 24 HRC for SHY685-NS — which matters for wear surfaces and threads.
SHY685-QTChoose it when surface hardness matters.
SHY685-NS vs SHY685-QT: 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.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Same in both: Elastic (Young's) Modulus 206 GPa29.9 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 55% · Compressive Strength 730 MPa106 ksi · Shear Strength 500 MPa72.5 ksi · Fatigue Strength (Endurance Limit) 390 MPa56.6 ksi · Hardness, Vickers 278 HV
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Min Service Temperature
Same in both: Thermal Conductivity 36 W/m·K20.8 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 350°C662 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7.2 % IACS · Electrical Resistivity 2.4×10⁻⁷ Ω·m9.45 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 13 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Weldability
Formability (cold)
Same in both: Machinability 38 / 100 · Machinability Rating (AISI 1212 = 100 %) 48% · Brazeability / Solderability 35 / 100 · Polishability 50 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 25%
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.
SHY685-NS vs SHY685-QT — frequently asked
What is the difference between SHY685-NS and SHY685-QT?
SHY685-NS and SHY685-QT are two conditions of the same steel grade, SHY685: NS (SHY685NS) versus QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. Both yield at about 720 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (SHY685NS versus quenched and tempered).
Which condition does FabDigit quote by default, NS or QT?
QT is the default SHY685 condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.
Which welds better, SHY685-NS or SHY685-QT?
SHY685-NS. Its weldability rates very good (70/100) against good (62/100) for SHY685-QT.
Ready to make it?
Upload a CAD file and FabDigit prices the part in SHY685-NS and SHY685-QT 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.