--- | ----- | -------- | -------- | -------- | --------- | -------------- | | A36 | — | 58-80 | 400-550 | 36 | 0.45-0.62 | 20-23 | | A992 | 50 | 65 | 450 | 50 | 0.77 | 21 | | A572 | 42 | 60 | 415 | 42 | 0.70 | 20 | | A572 | 50 | 65 | 450 | 50 | 0.77 | 18 | | A572 | 55 | 70 | 485 | 55 | 0.79 | 17 | | A572 | 60 | 75 | 520 | 60 | 0.80 | 16 | | A572 | 65 | 80 | 550 | 65 | 0.81 | 15 | | A588 | — | 70 | 485 | 50 | 0.71 | 18 | | A514 | — | 110-130 | 760-895 | 100 | 0.77-0.91 | 14-18 | | A709 | 36 | 58 | 400 | 36 | 0.62 | 20 | | A709 | 50 | 65 | 450 | 50 | 0.77 | 18 | | A709 | 50W | 70 | 485 | 50 | 0.71 | 18 | | A1043 | 36 | 58 | 400 | 36 | 0.62 | 21 | | A1043 | 50 | 65 | 450 | 50 | 0.77 | 19 |
Hollow Structural Sections
| ASTM Spec | Grade | Fu (ksi) | Fy (ksi) | Notes |
|---|---|---|---|---|
| A500 Gr B (round) | — | 58 | 42 | Most common round HSS |
| A500 Gr B (rect) | — | 58 | 46 | Most common rect HSS |
| A500 Gr C (round) | — | 62 | 46 | Higher strength round |
| A500 Gr C (rect) | — | 62 | 50 | Higher strength rect |
| A501 | — | 58 | 36 | Hot-formed HSS |
| A1085 | — | 65 | 50 | Tight tolerances, Charpy required |
Fasteners
| ASTM Spec | Grade | Fu (ksi) | Application |
|---|---|---|---|
| A307 | Gr A | 60 | Common (unfinished) bolts |
| A325 | 1/2-1 in | 120 | High-strength structural bolts |
| A325 | >1-1.5 in | 105 | Oversized high-strength bolts |
| A490 | — | 150 | Alloy steel structural bolts |
| A490M | — | 150 | Metric equivalent |
| F3125 Gr A325 | — | 120 | Consolidated spec |
| F3125 Gr A490 | — | 150 | Consolidated spec |
Stainless Steel
| UNS Number | Type | Fu (ksi) | Fy (ksi) | Elongation (%) |
|---|---|---|---|---|
| S30400 | 304 | 75-90 | 30-40 | 40-50 |
| S31600 | 316 | 75-90 | 30-40 | 40-50 |
| S32100 | 321 | 75-90 | 30-40 | 40-50 |
| S34700 | 347 | 75-90 | 30-40 | 40-50 |
| S41000 | 410 | 65-90 | 30-65 | 15-25 |
| S43000 | 430 | 65-75 | 30-40 | 20-25 |
| S17400 | 17-4PH | 135-170 | 110-145 | 8-14 |
Specialty and Tool Steels
| Steel Type | Fu Range (ksi) | Typical Application |
|---|---|---|
| Spring steel (1070) | 100-140 | Springs, clips |
| Spring steel (1095) | 120-180 | High-stress springs |
| 4140 alloy | 95-180 | Shaft, gears, forgings |
| 4340 alloy | 110-220 | Aircraft, heavy forgings |
| 8620 alloy | 80-130 | Case-hardened parts |
| Tool steel (O1) | 200-280 | Cold-work tools |
| Tool steel (D2) | 250-300 | Blanking dies |
| Tool steel (A2) | 230-280 | Forming dies |
| Tool steel (M2) | 280-350 | Cutting tools |
| Tool steel (H13) | 210-280 | Die casting dies |
Tensile Strength vs Yield Strength in Design
AISC Design Checks Using Fu
| Design Check | AISC Section | Formula | When It Controls |
|---|---|---|---|
| Tension fracture | D2 | ÃÂÃÂFuAe (ÃÂÃÂ=0.75) | Net section of tension members |
| Bolt bearing | J3.10 | Based on Fu of connected part | Thin connected elements |
| Bolt tearout | J3.10 | 1.2ÃÂÃÂFuLCt (ÃÂÃÂ=0.75) | Short edge distances |
| Block shear | J4.3 | Combination of Fy and Fu | Gusset plates, cope blocks |
| Weld metal | J2.4 | 0.6FEXX (FEXX = electrode Fu) | Fillet weld capacity |
Block Shear Strength (Uses Both Fy and Fu)
Block shear rupture combines tension fracture on one plane with shear yielding or fracture on the perpendicular plane:
ÃÂÃÂRn = ÃÂàÃÂà[0.6FuAnv + UbsFuAnt] âÃÂä ÃÂàÃÂà[0.6FyAgv + UbsFuAnt]
where ÃÂÃÂ = 0.75, Anv = net shear area, Ant = net tension area, Agv = gross shear area, Ubs = uniformity factor.
Tensile Testing Methods
| Method | Standard | Specimen | Speed |
|---|---|---|---|
| Standard tensile | ASTM E8/E8M | Round or rectangular | Per specification |
| Elevated temperature | ASTM E21 | Subsize round | Per specification |
| Fastener testing | ASTM F606 | Full-size bolt | Controlled rate |
Typical specimen dimensions:
- Round: 0.500 in diameter, 2.0 in gauge length
- Rectangular (plate): 1.5 in wide, gauge length = 2.0 in
- Subsize: 0.250 in diameter, 1.0 in gauge length
Frequently Asked Questions
What is the tensile strength of A36 steel? A36 has a minimum tensile strength of 58 ksi (400 MPa). The range is 58-80 ksi depending on thickness. For plates over 8 inches thick, Fu = 58 ksi minimum.
What is the difference between yield and tensile strength? Yield strength (Fy) is the stress where permanent deformation begins. Tensile strength (Fu) is the maximum stress before fracture. Fu is always greater than Fy. The gap between them determines how much the steel can deform before breaking (ductility).
Why does AISC use Fu for fracture checks? Fracture is a sudden, brittle failure mode that occurs at the tensile strength. It is less predictable than yielding and has no warning signs. AISC uses Fu with a lower resistance factor (ÃÂÃÂ = 0.75 vs 0.90 for yielding) to provide additional safety margin against brittle failure.
What steel has the highest tensile strength? Among structural steels, ASTM A514 (quenched and tempered) has the highest at 110-130 ksi. Tool steels can exceed 300 ksi but are not used for structural applications. Maraging steels reach 350+ ksi in aerospace.
Does cold working increase tensile strength? Yes. Cold working (cold rolling, drawing) strain-hardens the steel, increasing both Fy and Fu while reducing ductility. Cold-formed steel members (AISI S100) rely on this strength increase.
Try it now: Check your steel tensile strength with our free Steel Grade Selection calculator âÃÂÃÂ
Related Pages
- Steel Yield Strength — Fy values by grade
- Steel Stress-Strain Curve — Complete stress-strain behavior
- Steel Grades — ASTM specifications
- Tension Member Design — AISC Chapter D checks
- Steel Material Properties — Comprehensive material data
Disclaimer
This is a calculation tool, not a substitute for professional engineering certification. All results must be independently verified by a licensed Professional Engineer (PE) or Structural Engineer (SE) before use in construction, fabrication, or permit documents. The user is responsible for the accuracy of all inputs and the verification of all outputs.
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Frequently Asked Questions
What is the recommended design procedure for this structural element?
The standard design procedure follows: (1) establish design criteria including applicable code, material grade, and loading; (2) determine loads and applicable load combinations; (3) analyze the structure for internal forces; (4) check member strength for all applicable limit states; (5) verify serviceability requirements; and (6) detail connections. Computer analysis is recommended for complex structures, but hand calculations should be used for verification of critical elements.
How do different design codes compare for this calculation?
AISC 360 (US), EN 1993 (Eurocode), AS 4100 (Australia), and CSA S16 (Canada) follow similar limit states design philosophy but differ in specific resistance factors, slenderness limits, and partial safety factors. Generally, EN 1993 uses partial factors on both load and resistance sides (ÃÂóM0 = 1.0, ÃÂóM1 = 1.0, ÃÂóM2 = 1.25), while AISC 360 uses a single resistance factor (ÃÂÃÂ). Engineers should verify which code is adopted in their jurisdiction.