- EN / Grade
- 300M VAR
- Other designations / UNS
- 4340M / E4340 Mod
UNS K44220 - Family
- Alloy steel
Behaviour governed by quenching and tempering
300M is not a PH stainless steel defined by an H900 ageing condition. Stock purchased for machining and the component’s final quenched-and-tempered condition are different. Final grinding, surface-damage control and protective processing should be considered together in the manufacturing plan for a high-strength part.
Why the specification number matters
Specifications used for 300M do not reproduce exactly the same chemistry and delivery condition. For example, AMS 6417 covers a vacuum-remelted bar and forging family, while AMS 6257 also specifies normalized-and-tempered delivery. One should not be selected in place of another without engineering review.
An enquiry that preserves the drawing requirements
Rather than specifying only 300M and a diameter, provide the specification revision, starting condition, section and inspection requirements. Crack tolerance and the operating environment also matter. High tensile strength does not automatically establish that fatigue or corrosion requirements have been met.
Typical application areas
Landing-gear components, highly loaded forgings, structural connections.
Product and cutting options
Share the section and dimensions you require for this grade. Availability is assessed for each request; the catalogue does not represent live stock.
What to specify in your enquiry
- Grade designation and applicable material standard
- Section, finished dimensions and machining allowance
- Quantity, delivery condition and certificate requirements
Frequently asked questions
Can I request 300M VAR in cut lengths?+
Share your required section, dimensions and quantity. Our team will assess suitable supply and cutting options for the specific grade.
Are the listed grade designations interchangeable?+
Designation systems can overlap, but they do not make every specification identical. Use the exact standard and certificate requirements defined by your project.