Steel Q690 vs S700MC
Steel · grade comparison
Steel Q690 and S700MC are both steel grades. Both yield at about 730 MPa — strength does not separate them. Q690 is the more ductile: elongation 16% versus 14% for S700MC, and Q690 is harder (25 HRC vs 23 HRC). Q690 runs hotter in service (400°C vs 300°C continuous). On the shop floor, S700MC welds better (excellent vs good) and Q690 sits in a lower cost tier (budget, $) than S700MC (standard, $$).
Q690Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
S700MCChoose it when it will be welded.
Q690 vs S700MC: 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
Shear Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Hardness, Rockwell B
Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.3 · Fracture Toughness (K_IC) 100 MPa·√m91 ksi·√in
Physical
Density and transition temperatures.
Melting Point (Solidus)
Liquidus Temperature
Same in both: Density 7.85 g/cm³0.28 lb/in³
Thermal
How each material carries heat and how hot it can run.
Latent Heat of Fusion
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 40 W/m·K23.1 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 · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Polishability
Brazeability / Solderability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 25%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Shock Resistance Index
Same in both: Thermal Diffusivity 10.8 mm²/s
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 | Q690 | S700MC |
|---|---|---|
| Sheet metal | — | Yes |
| Default condition | — | TMCP |
| Relative cost | $ Budget | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
| Black Oxide | — | Yes |
| Cerakote | — | Yes |
| Chrome Plating | — | Yes |
| E-Coating | — | Yes |
| Hot-Dip Galvanizing | — | Yes |
| Nickel Plating | — | Yes |
| PTFE Coating | — | Yes |
| Painting | — | Yes |
| Powder Coating | — | Yes |
| Tin Plating | — | Yes |
| Zinc Plating | — | Yes |
| Zinc-Flake (Dip-Spin) Coating | — | Yes |
| Zinc-Nickel Plating | — | 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.
Q690 vs S700MC — frequently asked
What is the difference between Q690 and S700MC?
Steel Q690 and S700MC are both steel grades. Both yield at about 730 MPa — strength does not separate them. Q690 is the more ductile: elongation 16% versus 14% for S700MC, and Q690 is harder (25 HRC vs 23 HRC).
Which is cheaper, Q690 or S700MC?
Q690 is the lower-cost material: it sits in the budget tier ($) while S700MC 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, Q690 or S700MC?
S700MC, by a small margin. Both rate fair for machinability — 45/100 against 40/100 for Q690; for welding the order is S700MC first (excellent, 85/100) then Q690 (good, 65/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in Q690 and S700MC 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.