CSA G40.21 covers the chemical and mechanical requirements for structural quality steel shapes, plates, and bars for use in general construction and engineering purposes.
G40.21 Types
| Type W | Weldable Steel |
|---|---|
| Type WT | Weldable Notch Tough Steel (low temperature) |
| Type R | Atmospheric Corrosion Resistant Steel |
| Type A | Atmospheric Corrosion Resistant Weldable Steel |
| Type AT | Atmospheric Corrosion Resistant Weldable Notch Tough Steel |
| Type Q | Quenched and Tempered Low Alloy Steel Plate Steel |
| Type QT | Quenched and Tempered Low Alloy Notch Tough Steel Plate |
G40.21 Grades, Types and Strength Levels
| Type | 38 | 44 | 50 | 55* | 60 | 70 | 80 | 100 |
|---|---|---|---|---|---|---|---|---|
| W | 38W | 44W | 50W | 55W | 60W | 70W | 80W | - |
| WT | 38WT | 44WT | 50WT | 55WT | 60WT | 70WT | 80WT | - |
| R | 50R | |||||||
| A | 50A | 60A | 70A | 80A | ||||
| AT | 50AT | 60AT | 70AT | 80AT | ||||
| Q | 100Q | |||||||
| QT | 100QT | |||||||
| *Grade 55W is available only as hollow sections, angles and bars. 55WT as hollow sections only | ||||||||
G40.21 Imperial / Metric Conversion
| Imperial, ksi | Metric, MPa |
|---|---|
| 38 | 260 |
| 44 | 300 |
| 50 | 350 |
| 55 | 380 |
| 60 | 400 |
| 70 | 480 |
| 80 | 550 |
| 100 | 700 |
G40.21 Mechanical Requirements for Plates, Bars, and Shapes
| Grade | Tensile, ksi | Yield, ksi min, up to 2-1/2” | Yield, ksi min, above 2-1/2” to 4” | Elongation, % min, Longitudinal in 8” |
|---|---|---|---|---|
| 38W | 60-85 | 38 | 36 | 20 |
| 44W | 65-90 | 44 | 40 | 20 |
| 50W | 65-95 | 50 | 46 | 19 |
| 55W | 70-95 | 55 | - | 18 |
| 60W | 75-100 | 60 | - | 16 |
| 70W | 85-115 | 70 | - | 15 |
| 80W | 90-125 | 80 | - | 13 |
| 38WT | 60-85 | 38 | 36 | 20 |
| 44WT | 65-90 | 44 | 40 | 20 |
| 50WT | 70-95 | 50 | 46 | 19 |
| 60WT | 75-100 | 60 | - | 18 |
| 70WT | 85-115 | 70 | - | 15 |
| 80WT | 90-125 | 80 | - | 13 |
| 50R | 70-95 | 50 | - | 19 |
| 50A | 70-95 | 50 | 50 | 19 |
| 60A | 75-100 | 60 | - | 18 |
| 70A | 85-115 | 70 | - | 15 |
| 80A | 90-125 | 80 | - | 13 |
| 50AT | 70-95 | 50 | 50 | 19 |
| 60AT | 75-100 | 60 | - | 18 |
| 70AT | 85-115 | 70 | - | 15 |
| 80AT | 90-125 | 80 | - | 13 |
| 100Q | 110-130 | 100 | 90 | 18 in 2” |
| 100QT | 110-130 | 100 | 90 | 18 in 2” |
| The above table has been abridged for clarity and relevance. The complete table can be found in the CSA standard at shop.csa.ca | ||||
G40.21 Chemical Requirements
| Grade | Carbonmax | Manganese | Phosphorous | Sulfur max | Silicon | Chromium | Nickel | Copper |
|---|---|---|---|---|---|---|---|---|
| 38W | 0.20 | 0.50-1.50 | 0.04 max | 0.05 | 0.40 max | - | - | - |
| 44W | 0.22 | 0.50-1.50 | 0.04 max | 0.05 | 0.40 max | - | - | - |
| 50W | 0.23 | 0.50-1.50 | 0.04 max | 0.05 | 0.40 max | - | - | - |
| 55W | 0.23 | 0.50-1.50 | 0.04 max | 0.05 | 0.40 max | - | - | - |
| 60W | 0.23 | 0.50-1.50 | 0.04 max | 0.05 | 0.40 max | - | - | - |
| 70W | 0.26 | 0.50-1.50 | 0.04 max | 0.05 | 0.40 max | - | - | - |
| 80W | 0.15 | 1.75 max | 0.04 max | 0.05 | 0.40 max | - | - | - |
| 38WT | 0.20 | 0.80-1.50 | 0.03 max | 0.04 | 0.15-0.40 | - | - | - |
| 44WT | 0.22 | 0.80-1.50 | 0.03 max | 0.04 | 0.15-0.40 | - | - | - |
| 50WT | 0.22 | 0.80-1.50 | 0.03 max | 0.04 | 0.15-0.40 | - | - | - |
| 60WT | 0.22 | 0.80-1.50 | 0.03 max | 0.04 | 0.15-0.40 | - | - | - |
| 70WT | 0.26 | 0.80-1.50 | 0.03 max | 0.04 | 0.15-0.40 | - | - | - |
| 80WT | 0.15 | 1.75 max | 0.03 max | 0.04 | 0.15-0.40 | - | - | - |
| 50R | 0.16 | 0.75 max | 0.05-0.15 | 0.04 | 0.75 max | 0.30-1.25 | 0.90 max | 0.20-0.60 |
| 50A | 0.20 | 0.75-1.35 | 0.03 max | 0.04 | 0.15-0.50 | 0.70 max | 0.90 max | 0.20-0.60 |
| 60A | 0.20 | 0.75-1.35 | 0.03 max | 0.04 | 0.15-0.50 | 0.70 max | 0.90 max | 0.20-0.60 |
| 70A | 0.20 | 1.00-1.60 | 0.025 max | 0.035 | 0.15-0.50 | 0.70 max | 0.25-0.50 | 0.20-0.60 |
| 80A | 0.15 | 1.75 max | 0.025 max | 0.035 | 0.15-0.50 | 0.70 max | 0.25-0.50 | 0.20-0.60 |
| 50AT | 0.20 | 0.75-1.35 | 0.03 max | 0.04 | 0.15-0.50 | 0.70 max | 0.90 max | 0.20-0.60 |
| 60AT | 0.20 | 0.75-1.35 | 0.03 max | 0.04 | 0.15-0.50 | 0.70 max | 0.90 max | 0.20-0.60 |
| 70AT | 0.20 | 1.00-1.60 | 0.025 max | 0.035 | 0.15-0.50 | 0.70 max | 0.25-0.50 | 0.20-0.60 |
| 80AT | 0.15 | 1.75 max | 0.025 max | 0.035 | 0.15-0.40 | 0.70 max | 0.25-0.50 | 0.20-0.60 |
| 100Q | 0.20 | 1.50 max | 0.03 max | 0.04 | 0.15-0.40 | - | - | - |
| 100QT | 0.20 | 1.50 max | 0.03 max | 0.04 | 0.15-0.40 | - | - | - |
| In addition, grades 100Q and 100QT shall have a Boron composition of 0.0005-0.005% The above table has been abridged for clarity and relevance. The complete table can be found in the CSA standard at shop.csa.ca | ||||||||
G40.21 Charpy Impact Testing
| Grade | Minimum Absorbed Energy, Categories 1-4, in ft-lb |
|---|---|
| 38WT | 15 |
| 44WT | 15 |
| 50WT | 20 |
| 55WT | 20 |
| 60WT | 20 |
| 70WT | 20 |
| 80WT | 20 |
| 50AT | 20 |
| 60AT | 20 |
| 70AT | 20 |
| 80AT | 20 |
| 100QT | 25 |
| Absorbed energy for Category 5 shall be specified by the purchaser | |
| Category | Test Temperature, °F |
|---|---|
| 1 | 32 |
| 2 | 0 |
| 3 | -20 |
| 4 | -50 |
| 5 | To be specified by purchaser |
Commentary on ASTM Equivalents
The most common merchant structural grade of CSA G40.21 is 44W(300W). Most steel mills in the US manufacture their merchant bars (rounds, flats) to meet both this grade and ASTM A36 in order to satisfy users on both sides of the border. Becoming more common in recent years is structural steel per 50W. ASTM A572/A529 grade 50 will typically satisfy these requirements. All of Portland Bolt’s A36 rounds bar will cross certify to 44W and our F1554G55 round bar will meet the requirements of grade 50W. There may be some other cross certification available on a case by case basis. Ask your Portland Bolt salesperson for more information.