Belleville Washers Basics
Belleville washers, also known as disc springs or cupped spring washers, are often used to solve vibration, thermal expansion, relaxation and bolt creep problems. Their conical configuration enables them to support high loads with relatively small deflections and solid heights compared to helical springs. Multiple Belleville washers may be stacked to modify the spring constant (or spring rate) or the amount of deflection. Stacking in the same direction will add the spring constant in parallel, creating a stiffer joint (with the same deflection). Stacking in an alternating direction is the same as adding common springs in series, resulting in a lower spring constant and greater deflection. Mixing and matching directions allow a specific spring constant and deflection capacity to be designed.
Belleville Washer Materials
Belleville washers are available in a variety of materials, which play a role in the suitability of the fasteners in different applications, such as enhancing resistance to corrosion from environmental elements or chemicals.
H-13 Tool Belleville Washers
H-13 Tool Steel is a versatile chromium molybdenum alloy that resists thermal fatigue cracking which occurs due to cyclic heating and cooling. H-13 Bellevilles are a common, economical washer commonly used in conjunction with ASTM A193 Grade B7 and B16 flange bolting.
17-7PH Stainless Steel Belleville Washers
17-7PH stainless steel is semi-austenitic and precipitation hardened. It exhibits high strength and hardness, corrosion resistance, and excellent fatigue properties, and is suitable for cryogenic service. 17-7PH Belleville Washers are commonly used on stainless steel grades of bolting including ASTM A193 and A320 Grade B8 and B8M, classes 1 and 2 (strain hardened).
Inconel 718 Belleville Washers
Inconel 718 is a versatile, high strength nickel base super alloy suitable for applications from cryogenic temperatures up to and beyond 1000° F. It possesses extremely high yield strength, tensile strength, and creep-rupture properties. Inconel 718 is typically chosen for Bellevilles that must perform in challenging operating conditions.
Phosphor Bronze Belleville Washers
Phosphor Bronze Belleville Washers are well suited for use in electrical connections. Electrical connections are often made up of different materials, with different components of the connection carrying varying levels of current. This causes non-uniform heating which results in differential thermal expansion which can lead to an increase in bolt load, and thermal cycling. Vibration and relaxing may also affect electrical components leading to a failure of the bolted joint. Phosphor Bronze Belleville Washers offer a solution to these challenges, and allow for secure connections under difficult operating conditions.
Carbon Steel Belleville Washers
Carbon Steel Belleville Washers are a common, economical solution to maintain the integrity of bolted connections in a variety of applications.
301 Stainless Steel Belleville Washers
301 Stainless Steel Belleville Washers are a common, economical solution to maintain the integrity of bolted connections in a variety of applications.