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Steel A387 Gr 9-ANN vs A387 Gr 9-CL1

Steel · A387 Gr 9 temper comparison

A387 Gr 9-ANN and A387 Gr 9-CL1 are two conditions of the same steel grade, A387 Gr 9: ANN (annealed) versus CL1 (class 1). The chemistry is identical, so every difference below comes from the condition. A387 Gr 9-CL1 is the stronger of the two: yield strength 300 MPa (43.5 ksi) against 270 MPa (39.2 ksi) for A387 Gr 9-ANN, about 11% more; tensile strength follows at 480 MPa (69.6 ksi) vs 450 MPa (65.3 ksi). A387 Gr 9-CL1 is harder — 160 HB against 150 HB for A387 Gr 9-ANN — which matters for wear surfaces and threads.

A387 Gr 9-CL1Choose it when strength drives the design, or when surface hardness matters.

A387 Gr 9-ANN vs A387 Gr 9-CL1: properties

A387 Gr 9-ANNA387 Gr 9-CL1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

450 MPa65.3 ksi
480 MPa69.6 ksi

Yield Strength (0.2% offset)

270 MPa39.2 ksi
300 MPa43.5 ksi

Elongation at Break

28%
26%

Reduction in Area

68%
65%

Compressive Strength

470 MPa68.2 ksi
300 MPa43.5 ksi

Shear Strength

385 MPa55.8 ksi
290 MPa42.1 ksi

Fatigue Strength (Endurance Limit)

205 MPa29.7 ksi
220 MPa31.9 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 ksi·√in
130 MPa·√m118 ksi·√in

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
80 J59 ft·lbf

Hardness, Brinell

150 HB
160 HB

Hardness, Rockwell B

80 HRB
84 HRB

Hardness, Vickers

158 HV
168 HV

Same in both: Elastic (Young's) Modulus 211 GPa30.6 Msi · Shear Modulus 82 GPa11.9 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Rockwell C 18 HRC

Physical

Density and transition temperatures.

Same in both: Density 7.78 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,505°C2,741 °F

Thermal

How each material carries heat and how hot it can run.

Same in both: Thermal Conductivity 29 W/m·K16.8 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.2 µm/m·K6.2 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 600°C1,112 °F · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 2.9 % IACS · Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.55 V · Corrosion Resistance 30 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

60 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
55%

Formability (cold)

55 / 100
50 / 100

Same in both: Weldability 45 / 100 · Brazeability / Solderability 40 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 BTU/lb · Embodied Carbon (primary production) 2.4 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%

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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleA387 Gr 9

A387 Gr 9-ANN vs A387 Gr 9-CL1 — frequently asked

Is A387 Gr 9-CL1 stronger than A387 Gr 9-ANN?

Yes. A387 Gr 9-CL1 has a typical yield strength of 300 MPa (43.5 ksi) against 270 MPa (39.2 ksi) for A387 Gr 9-ANN — about 11% more. Tensile strength is 480 MPa (69.6 ksi) vs 450 MPa (65.3 ksi).

Which condition does FabDigit quote by default, ANN or CL1?

CL2 is the default A387 Gr 9 condition in the FabDigit quote flow (neither ANN nor CL1). 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 is easier to machine, A387 Gr 9-ANN or A387 Gr 9-CL1?

A387 Gr 9-ANN, by a small margin. Both rate good for machinability — 60/100 against 55/100 for A387 Gr 9-CL1.

Ready to make it?

Upload a CAD file and FabDigit prices the part in A387 Gr 9-ANN and A387 Gr 9-CL1 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.