คู่มือเทคนิค: 630, 631 and 632 stainless disc springs

Why precipitation-hardening stainless is useful

Disc springs need elastic performance, not only corrosion resistance. Common stainless grades may resist the environment but lack the spring strength or fatigue behavior required for a compact load-control component.

Precipitation-hardening stainless grades help bridge that gap for many industrial applications.

How 630, 631 and 632 are typically discussed

630, also known as 17-4PH, is often associated with strong mechanical properties after aging. 631, also known as 17-7PH, is widely used in spring applications because it balances corrosion resistance and spring temper capability. 632, also known as 15-7Mo, adds a molybdenum-bearing stainless option that may fit demanding spring reviews.

The final choice depends on the working stress, required fatigue life, temperature band, corrosion severity and available production route.

• 630 / 17-4PH: strength-focused precipitation-hardening stainless.
• 631 / 17-7PH: common stainless spring material for elastic components.
• 632 / 15-7Mo: stainless spring option for selected corrosion and strength balances.

Where these grades fit in applications

These stainless options are useful in marine equipment, food and pharmaceutical machinery, outdoor mechanisms, chemical-process accessories and valve assemblies where ordinary spring steel creates corrosion or contamination concerns.

They are not automatically a replacement for nickel alloys in severe heat or aggressive chemical exposure, but they often provide a practical mid-range solution.

Buyer information that prevents over-specification

Buyers should define whether the main concern is corrosion, fatigue, temperature, cleanliness or replacement interval. Without that context, it is easy to over-specify a premium material or under-specify a grade that cannot hold the required spring behavior.

For repeat programs, material condition, heat treatment and inspection documentation should be agreed before sample approval.