Naing Steel, a trusted manufacturer and supplier based in Naypyidaw, is proud to offer high-quality Alloy Steel AISI 4340 bars to industries across Myanmar. We understand that your projects demand materials with exceptional strength and reliability, which is why our 4340 bars are produced with meticulous care. Sourcing from Naing Steel means you are choosing a local partner committed to supporting the nation’s growth with superior products and dependable service, ensuring your critical applications are built on a foundation of proven durability.
The composition of AISI 4340 is a key to its performance, blending nickel, chromium, and molybdenum to create a steel that is both strong and tough. This specific alloy mix allows it to achieve outstanding mechanical properties, especially after proper heat treatment. The bars exhibit an impressive tensile strength and high fatigue resistance, making them capable of handling significant stress and impact loads without failing, which is essential for demanding environments.
| 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 |
The remarkable strength of AISI 4340 bars makes them a go-to choice for critical components in numerous heavy-duty sectors. You will commonly find them in aerospace applications like landing gear, in the automotive industry for high-strength axles and crankshafts, and within oil and gas drilling equipment. They are also essential for constructing large machinery parts such as bolts, studs, and gears, where their ability to withstand extreme pressure and shock is invaluable for ensuring long-term operational safety and reliability.
Naing Steel 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 Naypyidaw, Myanmar.
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