17-4 Stainless Steel Round Bar Supplier

The properties below are specified for chromium-nickel bar products in ASTM A564, which is the most commonly available product form for 17-4. Other product forms, such as plate and forgings, are governed by their own respective specifications and may have similar, but not necessarily identical, properties.

Typical applications include:

• Valves
• Gears
• Plastic moulding dies
• High strength shaft (including pump shafts)
• Boat propeller shafts
• Engine Parts

17-4 stainless steel offers good resistance to a wide range of corrosive environments, similar to Grade 304, though it is subject to pitting and crevice corrosion in warm chloride environments. Resistance to stress corrosion cracking improves with higher aging temperatures, and 17-4 is highly resistant when aged at 550°C or higher.

Corrosion resistance drops substantially in the solution-treated Condition A, so this condition should be avoided even if its hardness meets requirements.

For applications with heavier chloride or marine exposure than 17-4 is suited for, 316 stainless steel offers stronger corrosion resistance.

17-4 has good oxidation resistance, but to avoid the reduction of its mechanical properties and hardness, it should not be used above its age-hardening temperature. Prolonged exposure in the 370-480°C range should be avoided if ambient-temperature toughness is critical.

Solution treatment (Condition A) is performed by heating the bar to 1040°C for half an hour, then cooling it to 30°C or below in air. Oil quenching may be used for small, non-intricate sections.

After solution treatment, a single low-temperature age-hardening treatment is applied to achieve the required properties. This treatment causes no distortion and only superficial discoloration, though a slight decrease in size occurs during hardening, approximately 0.05% for Condition H900 and 0.10% for H1150.

Typical mechanical properties achieved after solution treating and then age hardening at the indicated temperatures are shown below. Each condition is designated by its age-hardening temperature in °F.

Contact our team to discuss which condition best fits your application, or ask about our heat-treating service for age hardening after purchase.

17-4 stainless steel can be successfully welded using all standard methods, and preheating is not necessary. Post-weld heat treatment can bring the weld metal's properties in line with those of the parent metal. However, as with other high-strength steels, care should be taken in both design and welding procedures to avoid concentrating stresses in the weldment.

17-4 stainless steel is usually supplied in the solution-treated condition, in which it can be machined. Machining rates approximate those of Grade 304. 17-4’s machinability decreases significantly once the bar has been fully aged to a higher hardness condition such as H900, so machining is typically completed before final heat treatment.