Flat Washers Or Spring Washers

Cost-conscious individuals often seek to reduce expenses by cutting expenses on flat pads or spring pads; in reality, these devices play an essential role in using bolts. Today Pandafastener will introduce flat washers and spring washers.

How to choose flat washers?

Flat washers are used as parts to prevent bolts and nuts from locking together, used widely across various fasteners, such as fasteners. But how to select the appropriate flat washer? Cushion is one type of flat washer which primarily acts to increase contact area between screws or large equipment and some kind of fastening mechanism, often used between nuts or nuts with each other - for the most effective sealing time storage it must also meet specific characteristics such as storage time constraints; there must also be essential characteristics associated with each cushion used:

1.When dealing with environments which are relatively harsh, flat gasket sealing should be employed; when certain temperatures and pressures occur during work sessions it should not leak easily. 2.If two flat surfaces contact, additional protection for sealing can be achieved for maximum sealing effect.

3.When under pressure and temperature conditions, gasket wrinkle resistance must be improved for better air leakage control; otherwise screws could break and create air leakage issues. 4.When using flat gaskets, be wary of infections spreading.

5.The use of flat pads allows them to be quickly disassembled, which plays an essential role in their selection. 

6.Be sure to utilize your flat pad regularly so as to maintain ideal temperature conditions in your environment.

In order to better use of flat pads, when choosing flat pads should try to choose anti-rust and anti-corrosion materials plated flat pads, so that not only saves time and effort, and the role of flat pads can be played to a very good.

When used with bolts and nuts, the selection standard of flat washers:

1.When selecting a gasket material, consideration must be made of electrochemical corrosion issues in relation to various metal contacts. Usually flat pad materials match those being connected such as steel, alloy steel, stainless steel and aluminum alloy; for conductive applications copper and its alloys should also be chosen as conductivity requirements.

2.When selecting flat pad sizes based on larger values of thread or screw diameter selection, softened materials (e.g. composite materials) should be connected. Spring washers corresponding to outer diameter of suitable selection should also be taken into consideration.

3.Pick a W washer under each bolt or screw head, in order to avoid interference between its rounded corner and its washer, such as flat washers with chamfered inner holes.

4.The diameter of key bolts or to increase their extrusion resistance should use steel washers; tension bolts or pull-shear composite bolt connections require these steel washers as well.

5.Special washers should be utilized when there are specific requirements in a part, such as for copper conductivity; air tightness requirements of airtight sealing washers.

The role of flat pads:

Increase the contact area between screws and machines. Eliminate spring pads when taking out screws on machine surfaces damage, by using flat pads instead. For this method to work well it should include spring pad on a flat pad adjacent to its surface of use, flat pad close to its nut, spring pad preventing loosening force playing some cushioning protection; but you could sacrifice flat pads as sacrifice pads as well.

Advantages:

① By increasing the contact area, parts can be protected from damage;

② Increasing the contact area reduces pressure between the nut and equipment and thus offers a.dditional protection.

Disadvantages:

① flat washers can not play the role of anti-vibration;

② flat washers also do not have the role of anti-loosening.

The role of spring washers

1.The function of the spring washer is to tighten a nut securely by providing elastic force against it - making sure that it cannot easily come loose or fall off. Ultimately, its purpose lies in tightening again after exerting force; increasing friction between nut and bolt.

2.Generally, flat pads should not be used with spring pads (although to protect fasteners and installation surfaces, consider both options when selecting pads for use.).

3.Flat pads are typically employed when there is an imbalance between soft textures and hard brittle ones, its purpose being to increase contact area, dispersal pressure evenly across it and prevent bad pressure textures from developing.

Advantages:

1.Spring washers have an excellent anti-loosening effect;

2.Have excellent anti-vibration capabilities;

3.Low manufacturing cost and installation is very straightforward.

Disadvantages: Spring washers can be affected by their material and process; if either does not meet expectations or heat treatment or other processes don't take place as planned, cracking phenomena is easy to occur - make sure that you purchase from a reliable manufacturer!

When to use flat pads and when to use spring pads?

1.In general, in the load is relatively small, as well as not subject to vibration loads can be used only flat pads.

2.In the case of large loads, as well as vibration loads, you must use flat washers, spring washers combination.

3.Spring washers are basically not used alone, are used in combination.

As flat and spring washers each play an essential part in the process, their roles differ widely; on occasion they work in concert to form protective units which help keep nuts tightened down without loosening and reduce vibration, making this combination an excellent option.

Application and failure form analysis of flat pad combination screws

According to statistics, a car using various types of fasteners up to several hundred types, thousands of which various types of flat gasket combination screws in the automobile fasteners on the application of a very wide range.

1.Flat pads in the assembly of the main functions

(1)Provide bearing surface

When the bolt or nut supporting surface is not enough to fully cover the connected parts, the gasket can provide a larger bearing surface;

(2) in order to reduce the pressure on the bearing surface or make it uniform

When the supporting surface area is too small or the pressure on the supporting surface is too high, shims can reduce the pressure on the supporting surface or make it more uniform;

(3) Stabilize the friction coefficient of the supporting surface

Shims can help stabilize friction coefficient of support surfaces (such as stamping parts). Local contact can become sensitive due to bite adhesion triggering local contact, leading to an increase in friction coefficient; as a result, shims may help increase its friction coefficient on support surfaces;

(4) Protect the Support Surface Tightening bolts or nuts has the potential of scratching joint surfaces, therefore gaskets play an essential role in protecting supporting surfaces during tightening operations;

2.Failure of flat pad combination bolts

Failure of flat pad combination bolts - gasket and bolt head under round corner interference

(1) Failure PhenomenonBattered combination bolts often suffer from one major source of failure: interference between gasket and bolt head corners, leading to abnormal assembly torque issues and poor turn.

An obvious indication of interference between a gasket and the lower corner of a bolt head is if there is an obvious gap between it and the bearing surface, leading to tightening difficulties; and that bolt and gasket cannot fit together perfectly.

(2) Failure Causes

When bolt gasket and bolt head under the rounded corner are combined together, interference usually arises due to either oversize of bolt head under rounded corner, or too small of gasket aperture design, leading to interference between gaskets and bolts after their combination.