Machinery's Handbook, 31st Edition
Disc Springs 351 8-4.2-0.2 and 40-20.4-1, respectively. Group 2 has 45 standard disc spring items. The smallest and the largest disc springs are 22.5-11.2-1.25 and 200-102-5.5, respectively. Group 3 includes 12 standard disc spring items. The smallest and the largest disc springs of this group are 125-64-8 and 250-127-14, respectively. Summary of Disc Spring Sizes Specified in DIN 2093
OD
ID
Thickness
Classification
Min.
Max
Min.
Max
Min.
Max
40 mm (1.575 in) 225 mm (8.858 in) 250 mm (9.843 in)
3.2 mm (0.126 in) 10.2 mm (0.402 in) 61 mm (2.402 in)
20.4 mm (0.803 in) 112 mm (4.409 in) 127 mm (5.000 in)
0.2 mm (0.008 in) 1.25 mm (0.049 in) 6.5 mm (0.256 in)
1.2 mm (0.047 in) 6 mm (0.236 in) 16 mm (0.630 in)
6 mm (0.236 in) 20 mm (0.787 in) 125 mm (4.921 in)
Group 1
Group 2
Group 3
The number of catalog items by disc spring dimensions depends on the manufacturer. Currently, the smallest disc spring is 6-3.2-0.3 and the largest is 250-127-16. One of the US disc spring manufacturers, Key Bellevilles, Inc. offers 190 catalog items. The greatest number of disc spring items can be found in Christian Bauer GmbH + Co. catalog. There are 291 disc spring catalog items in all three groups. Disc Spring Contact Surfaces.— Disc springs are manufactured with and without con tact (also called load-bearing) surfaces. Contact surfaces are small flats at points 1 and 3 in Fig. 2, adjacent to the corner radii of the spring. The width of the contact surfaces w depends on the outside diameter D of the spring, and its value is approximately w = D / 150.
F
d
1
H
t'
3
F
D
Fig. 2. Disc Spring with Contact Surfaces Disc springs of Group 1 and Group 2 , that are contained in the DIN 2093 standard, do not have contact surfaces, although some Group 2 disc springs not included in DIN 2093 are manufactured with contact surfaces. All disc springs of Group 3 (standard and nonstandard) are manufactured with contact surfaces. Almost all disc springs with con- tact surfaces are manufactured with reduced thickness. Disc springs without contact surfaces have a corner radii r whose value depends on the spring thickness t . One disc spring manufacturer recommends the following relationship: r = t / 6 Disc Spring Materials .— A wide variety of materials are available for disc springs, but selection of the material depends mainly on application. High-carbon steels are used only for Group 1 disc springs. AISI 1070 and AISI 1095 carbon steels are used in the United States. Similar high-carbon steels such as DIN 1.1231 and DIN 1.1238 (Germany), and BS 060 A67 and BS 060 A78 (Great Britain) are used in other countries. The most common materials for Groups 2 and 3 springs operating under normal conditions are
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