Thabiso Steel is a reputable manufacturer and supplier located in Cape Town, South Africa, with a focus on high-performance Alloy Steel AISI 4340 Bars. Known for their precision engineering and top-notch material quality, the company provides bars that showcase remarkable toughness, strength, and fatigue resistance. Thabiso Steel guarantees that each bar complies with global industrial standards, meeting the rigorous demands of the aerospace, automotive, and engineering industries. With a strong dedication to innovation and quality assurance, Thabiso Steel offers reliable and durable Alloy Steel AISI 4340 Bars that are built to perform effectively under extreme mechanical and thermal stress.
Alloy Steel AISI 4340 Bars are primarily made up of nickel, chromium, and molybdenum, along with carbon, manganese, and silicon. This well-balanced alloying improves hardenability, ductility, and impact resistance. The bars boast a tensile strength between 930–1080 MPa and a yield strength of around 835 MPa, along with excellent toughness and fatigue strength. After heat treatment, they achieve a hardness of 24–35 HRC and maintain good machinability and wear resistance, making them perfect for high-stress mechanical components and heavy-duty industrial applications.
| Sizes | 2-100mm A/F |
|---|---|
| Tolerance | H9, H8, H10, K12, H13K9, K10, H11, H12, K11 |
| Round bar Sizes | Diameter: 3-~800mm |
| Technique | Hot Rolled, Cold Drawn, Cold Rolled, Forged, Rod |
| Processing | Bar cutting to 650mm |
| Surface | Bright, Hot Rolled Pickled, Sand Blasting Finished, Hairline, Cold Drawn, Polished suppliers |
| Condition | Hardened and tempered, annealed |
| Form | Precision Square, Ingot, T-Bar, Rod, Round, Welding Rod, I/H Bar, Flat Bar, Blocks, Rings, Rectangle, Hex (A/F), Hollow, Threaded, Profiles, Ground Bar, Channel Bar, Billet, Triangle, Round Rod, Half Round Bar, Forging etc. |
| Square bar Sizes | 4 to 100mm |
| Finish | Hot rolled annealed, Bright, smooth turned, Polish, Rough Turned, Cold (bright) drawn, centreless ground, Grinding, peeled, hot rolled, slit rolled edge, Centreless Ground & Black. |
| Flat bar Sizes | Width: 10 – 500 millimeter Thick.: 2 to 100 millimeter |
| C | Mn | Si | S | P | Cr | Ni | Mo | |
| SAE – 4340 | .38- .43 | .60 – .80 | .15 – .35 | .035 MAX | .040 MAX | .70 – .90 | 1.65 -2.00 | .20 – .30 |
| Tensile strength kgf/mm² | Yield strength kgf/mm² | Elongation % | Cross section reduction rate % | Impact value | Hardness Hb |
|---|---|---|---|---|---|
| ≧100 | ≧90 | ≧16 | ≧45 | ≧7 | 293~352 |
We provide products that come with both mill test certificates and third-party test certificates, ensuring the highest standards of quality and compliance.
| SIZE IN INCHES | ROUND | SQUARE | OCTAGON | HEXAGON | SIZE IN INCHES | ROUND | SQUARE | OCTAGON | HEXAGON |
| 1/16 | .010 | .013 | .011 | .012 | 11/16 | 1.262 | 1.607 | 1.333 | 1.392 |
| 5/64 | .017 | .022 | .018 | .019 | 45/64 | 1.320 | 1.681 | 1.394 | 1.456 |
| 3/32 | .023 | .029 | .024 | .025 | 23/32 | 1.380 | 1.756 | 1.487 | 1.521 |
| 7/64 | .031 | .039 | .033 | .034 | 47/64 | 1.440 | 1.834 | 1.521 | 1.588 |
| 1/8 | .042 | .053 | .044 | .046 | 3/4 | 1.502 | 1.913 | 1.586 | 1.656 |
| 9/64 | .053 | .067 | .056 | .058 | 25/32 | 1.630 | 2.075 | 1.721 | 1.797 |
| 5/32 | .065 | .083 | .069 | .072 | 13/16 | 1.763 | 2.245 | 1.862 | 1.944 |
| 11/64 | .079 | .100 | .083 | .087 | 27/32 | 1.901 | 2.421 | 2.008 | 2.096 |
| 3/16 | .094 | .120 | .099 | .104 | 7/8 | 2.045 | 2.603 | 2.159 | 2.254 |
| 13/64 | .110 | .140 | .116 | .121 | 29/32 | 2.193 | 2.792 | 2.316 | 2.418 |
| 7/32 | .128 | .163 | .135 | .141 | 15/16 | 2.347 | 2.988 | 2.479 | 2.588 |
| 15/64 | .147 | .187 | .155 | .162 | 31/32 | 2.506 | 3.191 | 2.646 | 2.763 |
| 1/4 | .167 | .213 | .176 | .184 | 1 | 2.670 | 3.400 | 2.820 | 2.945 |
|---|---|---|---|---|---|---|---|---|---|
| 17/64 | .188 | .240 | .199 | .207 | 1-1/16 | 3.015 | 3.838 | 3.183 | 3.324 |
| 9/32 | .211 | .269 | .223 | .233 | 1-1/8 | 3.380 | 4.303 | 3.569 | 3.727 |
| 19/64 | .235 | .300 | .248 | .259 | 1-3/16 | 3.766 | 4.795 | 3.977 | 4.152 |
| 5/16 | .261 | .332 | .275 | .288 | 1-1/4 | 4.172 | 5.313 | 4.407 | 4.601 |
| 21/64 | .288 | .360 | .304 | .318 | 1-5/16 | 4.600 | 5.857 | 4.858 | 5.072 |
| 11/32 | .316 | .402 | .334 | .348 | 1-3/8 | 5.049 | 6.428 | 5.332 | 5.567 |
| 23/64 | .345 | .439 | .364 | .381 | 1-7/16 | 5.518 | 7.026 | 5.827 | 6.085 |
| 3/8 | .376 | .478 | .397 | .414 | 1-1/2 | 6.008 | 7.650 | 6.345 | 6.625 |
| 25/64 | .408 | .519 | .431 | .450 | 1-9/16 | 6.519 | 8.301 | 6.885 | 7.189 |
| 13/32 | .441 | .561 | .466 | .486 | 1-5/8 | 7.051 | 8.978 | 7.446 | 7.775 |
| 27/64 | .475 | .605 | .502 | .524 | 1-11/16 | 7.604 | 9.682 | 8.030 | 8.385 |
| 7/16 | .511 | .651 | .540 | .564 | 1-3/4 | 8.178 | 10.41 | 8.634 | 9.018 |
| 29/64 | .548 | .698 | .579 | .604 | 1-13/16 | 8.773 | 11.17 | 9.265 | 9.673 |
| 15/32 | .587 | .747 | .620 | .647 | 1-7/8 | 9.388 | 11.95 | 9.911 | 10.35 |
| 31/64 | .627 | .798 | .662 | .692 | 1-15/16 | 10.02 | 12.76 | 10.58 | 11.05 |
| 1/2 | .668 | .850 | .705 | .736 | 2 | 10.68 | 13.60 | 11.28 | 11.78 |
| 33/64 | .710 | .904 | .750 | .783 | 2-1/16 | 11.36 | 14.46 | 11.99 | 12.53 |
| 17/32 | .754 | .960 | .796 | .831 | 2-1/8 | 12.06 | 15.35 | 12.73 | 13.30 |
| 35/64 | .799 | 1.017 | .844 | .881 | 2-3/16 | 12.78 | 16.27 | 13.49 | 14.09 |
| 9/16 | .845 | 1.076 | .892 | .932 | 2-1/4 | 13.52 | 17.21 | 14.27 | 14.91 |
| 37/64 | .893 | 1.136 | .943 | .985 | 2-5/16 | 14.28 | 18.18 | 15.08 | 15.75 |
| 19/32 | .941 | 1.199 | .994 | 1.038 | 2-3/8 | 15.06 | 19.18 | 15.91 | 16.61 |
| 39/64 | .992 | 1.263 | 1.048 | 1.094 | 2-7/16 | 15.87 | 20.20 | 16.75 | 17.49 |
| 5/8 | 1.043 | 1.328 | 1.102 | 1.150 | 2-1/2 | 16.69 | 21.25 | 17.62 | 18.40 |
| 41/64 | 1.096 | 1.395 | 1.207 | 1.209 | 2-9/16 | 17.53 | 22.33 | 18.52 | 19.34 |
| 21/32 | 1.150 | 1.464 | 1.214 | 1.268 | 2-5/8 | 18.40 | 23.43 | 19.43 | 20.29 |
| 43/64 | 1.205 | 1.535 | 1.272 | 1.329 | 2-11/16 | 19.29 | 24.56 | 20.37 | 21.27 |
Alloy Steel AISI 4340 Bars find extensive use in industries that demand superior strength and durability. They are commonly utilized in the production of aircraft landing gears, drive shafts, crankshafts, connecting rods, gears, and heavy-duty axles. Additionally, these bars are employed in oil and gas drilling equipment, defense machinery, and power transmission systems. Their outstanding toughness and resistance to wear and fatigue make them ideal for components subjected to dynamic loads and high stress. In both marine and automotive sectors, AISI 4340 Bars ensure long-lasting performance and safety even under the most challenging operational conditions.
ThabisoSteel is a leading manufacturer, supplier and exporter of high-quality Carbon Steel, Alloy Steel, Mild Steel and Galvanized Steel products. Our extensive product range includes Pipes, Tubes, Flanges, Pipe Fittings, Forged Fittings, Sheets and Plates, catering to various industries in Cape Town, South Africa.
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