STAINLESS STEEL MATERIALS
There are various stainless steels, which by their properties are adequate to make belleville washers DIN 2093 and Belleville Fasteners DIN 6796. The elastic properties of these steels are different than standard steels of disc springs (51CrV4 and CK67). This condition must be taken into consideration in the calculations, varing the Young module in the case we select a stainless steel to our springs.
More common materials are the 1.4310 (AISI 301) for springs which thickness is not higher than 2 mm and in the case of 1.4568 (AISI 631) for all kind of thickness of DIN 2093 serie. The second one, 1.4568 presents better range against temperature. However, if temperature and corrosion are extreme, commonest option is Inconel 718, which is also a non-magnetic alloy. This last option is the one with a highest cost, consequently it is only applied when characteristics of the two first steels are not enough for our application justifying then the cost.
We detail their main characteristics:
1.4310 (AISI 301) X10CrNi18-8
Stainless steel for belleville washers Din 17.224. Used in pieces with 2,0 mm of thickness
- -200ºC at +100ºC
- 190 KN/mm at 20ºC
- 185 KN/mm at 100ºC
1.4568 (AISI 631) X7CrNiAl17-7
Also known as 17-7PH. Stainless steel for belleville washers Din 17.224. Appropriate for springs fabrication with any thickness. Not recommended on applications with chloride or fluoride. In location close to maritime environments, the application of silver nickel covering can be recommend. Very appropriate for cryogenic applications as well.
- -200ºC at +350ºC
- 200 KN/mm at 20ºC
- 195 KN/mm at 100ºC
- 185 KN/mm at 200ºC
- 175 KN/mm at 300ºC
- 165 KN/mm at 400ºC
2.4668 (Inconel 718) NiCr19NbMo
Nickel alloy for belleville washers (Non-magnetic). Din 65021. One of the options in available materials, with the best anticorrosive properties without any additional protection needed.
- -260ºC at +700ºC
- 200 KN/mm at 20ºC
- 195 KN/mm at 100ºC
- 190 KN/mm at 200ºC
- 184 KN/mm at 300ºC
- 178 KN/mm at 400ºC
- 172 KN/mm at 500ºC
- 167 KN/mm at 600ºC
- 160 KN/mm at 700ºC
In addition to this 3 options, there are other materials which are also appropriate for belleville washers fabrication. For example:
- X4CrNiMo17-12-2 ( 1.4401)
- NiCr20Co18T (Nimonic 90)
- X35CrMo17 (1.4122)
- NiCr15Fe7TiAl (Inconel X750)
- Co40, Ni26, Cr12, Mo, W, Ti, Al, Bal, Fe (Duratherm 600)
- CuBe2 (beryllium copper 2.1247)
- TiAl6V4 (3.7165)
Nevertheless, the fact they are not so common materials makes us advise you against their use. They mean an expensive solution with long-term deliveries. Springs made in these last materials are not standard and require always an special production.