- EN / Grade
- HP9-4-30
- Other designations / UNS
- HP9-4-.30 · Vac Melt
UNS K91283 - Family
- Alloy steel
Stock condition does not define final strength
Annealed material purchased for machining is distinct from the finished component’s heat-treated state. Section size and processing affect the required strength–toughness balance. A single working hardness cannot be inferred from the HP9-4-30 name; the order should define delivery condition and subsequent processing.
Strength alone is insufficient in a welded structure
The grade is also considered for welded structures, but weld metal, heat-affected zone and base material require separate verification. Adequate post-weld tensile strength does not establish unchanged toughness or stress-corrosion resistance. The welded-component plan should not be separated from material selection.
Specify the vacuum-melting requirement
Include dimensions, product form, melting route and documentation needs. AMS 6526 is one example used for the bar, forging and mechanical-tubing family; it cannot be transferred to all flat products. State corrosion protection and inspection requirements together with the component’s operating environment.
Typical application areas
Specialized aerospace structures, highly loaded shafts, critical component blanks.
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 HP9-4-30 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.