FAQ

This page provides answers to Frequently Asked Questions - if you don´t get a satisfactory answer here, please don´t hesitate to contact us.

Query	Response or Data
What should I do if I can't find the size and dimensions of the disc spring I need?	We'll suggest a close match, but if an exact match is needed, this does not pose a problem. We are well known for our bespoke and non-standard disc spring solutions. We have our own toolmaking team and heat treatment capability, so die making is very quick.
Do you carry stock in every size you manufacture? If not, how long will my order take?	For the DIN6796-Heavy Load Washer range we generally have stock up to a bolt size of M33, everything else up to M125 is manufactured at order time. Manufacture takes 5-7 days if we are not busy. For the DIN-EN 16983-Disc Springs, if you are a repeat customer, we manufacture and reserve your standing order so that you can have immediate collection. Because we manufacture well over 500 different disc spring across the 3 different Groups, it is not practical to keep stock in each size. However, the popular sizes in Group 3 (1.6->6.0mm in material thickness) are always kept in stock.
What is the difference between DIN-EN 16983 and DIN 2093	Strictly speaking two sets of standards are involved DIN EN 16983 – Quality requirements, Dimensions, which replaces DIN 2093 DIN EN 16984 – Calculation, which replaces DIN 2094 Both the DIN 2093 and DIN 2094 were German standards and have now been incorporated into the European standards, and changes to content including any technical changes have NOT taken place
Are you just an onseller or do you manufacture yourself and if so how can we be assured of a quality product?	We are one of the few manufacturers worldwide that will provide you with: A confirmation Load Characteristic Curve for the individual disc spring or the stack you are making up A Material cert of the metal used in your disc spring's manufctaure A Heat Treatment cert with the Rockwell C hardness attained, and very importantly, assurance on the tempering cycle. On request-An independent Load Cycle Test, confirming the Loac Char Curve predicted. This is done by the CSIR or SGS Metlab On request-Our ISO9001:2015 QMS artefacts. For any batch of disc springs we invoice, we can trace back who signed off the tooling, who checked the material, the operator and machinist who worked on your disc springs, who conducted the heat treatment hardness tests etc.
What kind of materials and metal do you use?	We use a range of materials, depending on key operating environment variables and conditions, such as: Ambient Operating Temperature Magnetic Flux Density Chemcial corrosiveness through the presence of acids, bases and oxidizers Industry Standards, espcially aviation and food The vast majority of instances only require either a high-carbon (SAE10xx) or an alloy steel (Chrome-Vandium), in dense flux environments we must prevent induction heating and use non-magnetic metal. High flux environments usually combine with a high ambient temperaature, and INCONEL is our preference. Conversely Beryllium Copper, is great for sub-zero temperatures where electical components predominate. For corrosive environments where non contamination is essential (as in food processing), we have high density polymer disc springs, approved by the FDA.
Where do you source your materials and metal?	All our Chrome-Vanadium alloys (SAE6150/50CrV4), non-magnetic high temperature (INCONEL-x750) and high carbon (65Mn/SAE1065) springsteel is imported in annealed 2500x1250mm plate/sheet form, in thicknesses from 0.5mm to 20mm.
What's the difference between a Disc Spring and a Load Washer if they are both Belleville Washers?	Disc Springs follow the DIN-EN-16983 standard whilst Load Washers follow the DIN6796 standard. They are designed to fulfill different functions for different applications. Load Washers follow the standrd bolt sizes, and there are far fewer versions, we have 30 sizes from M2 to M125, whereas disc springs are designed to meet specific (and generally dynamic) loading or energy absorbing functions. As a result there at least 500 different standard/common disc spring sizes. The DIN 6796 High Load washers are used individually to secure a Static bolted connection. The high torque applied and resulting force ensures a permanent pressure to the union between a hardened bolt and its nut to prevent the loss of pre-load and subsequent loosening. Disc Springs are used as springs, either individually or in stacks. They will generally have a dynamic load applied to them, rather than a single static load. The last big difference is that disc springs have much stricter tolerances, as they have more specific design performance requirements, used in mission critical applications.
Are DIN6796 Load Washers made from the same materials and in the same manner as DIN2093/EN-16983 Disc Springs?	Smaller OD and thickness DIN6796 load washers are made in the same manner as Group 1 & 2 DIN2093 Disc Springs, except for the application of key radii, final polishing and surface treatment steps. Larger DIN6796 and Group 3 DIN2093 Disc Springs are also made from Chrome-Vanadium Spring Steel, initially lazer cut into blanks that are CNC machined. These Disc Springs have contact flats/working surfaces machined, whilst the Load washers do not. The same stringent heat treatment quenching and tempering protocols must be observed.
What is a reduced thickness disc spring?	For disc springs with a thickness of more than 6.0 mm (there are one or two excpetions), DIN-EN 16983 specifies small contact surfaces. Using a contact flat shortens the the moment arm, think of a lever as it gets shortened, more force is needed, to move an equivalent load. Thus all things being equal, if you introduce a contact flat, the disc spring requires a greater load for the same deflection. For very practical reasons of interchangeability, which means maintaining the free height of a spring, and matching loads as closely as possible, the thickness of the disc spring must be reduced. The use of contact flats (or annuli as we call them) are intended to:
What is a contact flat?	We call the contact flat, an annulus, the DIN 2092 refers to it as a ground surface end, and the SAE HS1582 Spring Design Manual as a Contact Bearing Flat. These have a purpose: to improve the definition of the point where the load is applied and in stack configurations, to reduce the friction on the stack guide These do substanitally improve performance, and prolong operational life substantially.