BelleFlex™ Home / Glossary

1074/1075 High Carbon Steel
A malleable, iron-based non-alloyed metal containing carbon, small amounts of manganese, and other elements. The 1075 designation is obsolete, since the acceptable carbon content range for both 1074 and 1075 High Carbon Steel is 0.70%-0.80%.

15-5 PH Stainless Steel
A martensitic precipitation-hardening stainless steel that is the ferrite-free version of 17-4 PH. It has high strength, is corrosion resistant, and has good mechanical properties. (Registered trademark of AK Steel)

17-4 PH Stainless Steel
A martensitic precipitation-hardening stainless steel, with high strength and hardness, resistance to corrosion, and excellent mechanical properties. It is the most widely used of all the precipitation-hardening stainless steels. (Registered trademark of AK Steel)

17-7 PH Stainless Steel
A semi-austenitic precipitation-hardening stainless steel, well-suited for applications requiring high strength and hardness, good fatigue properties, corrosion resistance, and minimum distortion upon heat treatment. 17-7 PH Stainless Steel, when stressed and exposed to corrosive environments, may be subject to spontaneous fracture. (Registered trademark of AK Steel)

300 Series Stainless Steel
Austenitic chromium-nickel stainless steels known for corrosion resistance and unusually fine mechanical properties.

6150 Alloy Steel
A fine-grained, highly abrasion-resistant carbon-chromium alloy steel. It contains chromium and vanadium for added impact hardness.

Belleville Disc Spring
A conical-shaped spring with an open center, shaped much like a washer. Belleville disc springs, typically, are used for cushioning heavy loads with short motion. They may be used singly or stacked in various combinations to modify the spring constant or amount of deflection. A Belleville disc spring may also be called a Belleville washer, Belleville spring, disc spring, conical spring, or spring washer.

Carpenter Custom 455 Stainless Steel
A martensitic age-hardenable, stainless steel alloy with high-strength and good corrosion resistance. Good spring characteristics exist even at relatively large diameters and thicknesses, allowing for a large range of sizes for corrosion-resistant springs. (Registered trademark of the Carpenter Technology Corporation)

Creep
A reduction in tension in a gasket or bolt due to factors from the normal course of use, such as vibration, high temperature, or load.

Elastic Limit
Maximum stress to which a material may be subjected and still return to its original condition upon release of load.

Flange Bolt
More commonly referred to as a stud bolt, this is a length of appropriate all thread material with a nut and Belleville disc spring at each end.

Flange Leakage
A leak that occurs at the point of the flange when the flange joint fails.

Flange Washer
A Belleville disc spring with an outer diameter/inner diameter ratio small enough to fit standard flanges.

Free Height
The overall height of an unloaded Belleville disc spring. Height is one of the four basic measurements of a Belleville disc spring.

H13 Tool Steel
A versatile, chromium-molybdenum alloy. Its characteristics include high toughness, resistance to thermal fatigue cracking, hardenability, and wear resistance.

HASTELLOY Alloys
A family of nickel-based superalloys widely used in chemical processing industries because they are extremely corrosion resistant. B2, B3, C-22HS, and C-276 provide high resistance to uniform general corrosion, localized corrosion, and stress corrosion cracking. (Registered trademark of Haynes International, Inc.)

INCONEL Alloys
INCONEL encompasses a family of nickel-chromium alloys. These alloys have high strength, weldability, and corrosion resistance at extreme temperature ranges. Temperatures for various applications can range from -400°F to 1300°F, depending on the alloy. (Registered trademark of the Special Metals Corporation)

Inside Diameter
The inner diameter measurement of a Belleville disc spring. Inside diameter (or ID) is one of the four basic measurements of a Belleville disc spring.

MONEL Alloys
Nickel-copper alloys with high strength and toughness at extreme temperature ranges. Very corrosion resistant, 400 and K-500 are commonly used in the chemical processing, oil and gas, electronics, and paper processing industries. (Registered trademark of the Special Metals Corporation)

Outside Diameter
The outer diameter measurement of a Belleville disc spring. Outside diameter (or OD) is one of the four basic measurements of a Belleville disc spring.

Permanent Set
A material has taken a “permanent set” when it is deflected so far that its elastic properties have been exceeded and it does not return to its original condition upon release of load.

PH 15-7 Mo Stainless Steel
A semi-austenitic precipitation-hardening stainless steel that provides high strength and hardness, corrosion resistance, and minimum distortion on heat treatment. (Registered trademark of AK Steel)

Poisson’s Ratio
The ratio expressed by the strain in the transverse direction relative to the strain in the longitudinal direction.

Relaxation
Loosening of a bolt or joint after it has been tightened.

Set
Permanent change of length, height, or position after a spring is stressed beyond the material's elastic limit.

Teflon
Fluoropolymer resins with resistance to high temperatures, chemical reaction, corrosion, and stress-cracking. (Registered trademark of DuPont)

Thickness
The thickness of the metal of a Belleville disc spring, also called "material thickness". Thickness is one of the four basic measurements of a Belleville disc spring.

WASPALOY Alloy
A nickel-base, age-hardenable alloy, which is strong and corrosion resistant at high temperatures. (Registered trademark of United Technologies Corporation)