A lesser known fact to non-gym goers is that weight plates can actually be made from different materials, resulting in dramatically different characteristics, depending on the material.
Two of the most commonly seen weight plates are that of the standardized bumper plate, and the more traditional iron plate; Each with their own specific uses and benefits.
To put it in a nutshell, bumper plates are far more resistant to wear and tear, but are not as cheap or accessible as iron plates - alongside a number of other characteristics that make one type of weight plate distinct from the other.
Bumper plates are a form of weight plate that feature a metallic inner core that is enveloped in a rubber coating, both protecting this metallic material and ensuring that the plate itself retains its shape despite significant impacts.
Bumper plates are frequently seen in olympic weightlifting competitions and similar weightlifting sports that involve dropping a barbell from relatively long distances, such as in powerlifting or crossfit.
The main purpose of using bumper plates over other kinds of plates is to protect the floor and the plates themselves from impact-related damage.
Due to the rubber coating that surrounds each bumper plate, lifters can drop them without worry of the inner metal material cracking or otherwise damaging whatever they may land on.
Furthermore, bumper plates feature a standardized diameter that make them more convenient to use with certain types of equipment.
Bumper plates are the ideal weight plate for practically every weightlifting sport, and are generally required in such competitions due to the higher specificity of standardization and quality that goes into manufacturing them.
Apart from these standardizations, the majority of commercially produced bumper plates are also color coded and shaped to exact standards.
Furthermore, unlike other types of weight plates, bumper plates make little noisy when dropped and are generally not susceptible to chipping or cracking.
Iron plates are among the first kinds of weight plates ever developed, usually being made of nearly-pure iron or an iron composite that provides excellent durability and accurate weight measurements for a relatively low cost.
The most common type of iron plate is that of cast-iron plates, of which will be coated in a finish or layer of paint that protects it from rusting in the short-term. Higher quality iron plates may even feature a coating made from material other than iron, of which can provide a myriad of benefits.
Iron plates serve the most basic of purposes; that of being a weight plate.
So much so, in fact, that iron plates are considered to be the “default” type of weight plate, being the most commonly seen in non-specialized gyms.
They are made from such a material due to the inherent durability and low cost in comparison to the amount of weight that can be purchased, maximizing commercial output and allowing lifters to purchase more plates than they would be able to with other types of weight plates.
Apart from the far lower financial cost of iron plates, they are also occasionally larger in diameter and offer more options between brands - meaning lifters that prefer wider or more narrow plates do not need to go out of their way to find iron plates that fit their needs.
These factors, alongside the greater customizability of iron plates, makes them the ideal type of plate for bodybuilders or those that do not plan to subject their equipment to significant impacts in a frequent manner.
One of the most obvious differences between bumper plates and iron plates is in the “jumps” between weight of each plate, with iron plates usually having 2.5-5 pound plates as their lowest increment, increasing to 10 pounds, 25 pounds and finally ending in the standard 45 pound plate.
This is distinct from the standardized bumper plate weight increment, of which will begin at 10 pounds, 15 pounds, and then succeedingly increase by 10 pound increments before finally stopping at the maximum 55 pound plate weight.
In essence, the difference between bumper plates and iron plates means that iron plates are the superior choice for gradual progressive overload training, as they allow the lifter to increase the weight of their lifts in smaller progressions.
Though both bumper plates and iron plates differ in terms of size between weight increments, they are still distinct from one another by the very nature of their size itself, regardless of the weight of the plate.
This is because - unlike iron plates - bumper plates are generally standardized to a certain thickness, and are otherwise incompatible with barbells other than the standard 2-inch olympic barbell or similarly sized bars.
Iron plates will generally also grow larger in diameter and width linearly with the amount of weight that is being used, whereas bumper plates are the same diameter regardless of how much they weigh.
While this may seem inconsequential, it does mean that more advanced lifters will be able to load more iron weight plates onto a standardized barbell than they would be able to with bumper plates instead.
Without a doubt, bumper plates vastly outclass iron plates in terms of durability - both to general environmental factors, as well as direct physical impact from being dropped or struck by other plates.
Such a difference in durability is because of the materials used to protect either type of plate, with iron plates usually only sporting a thin finish or similarly weak outer coating, whereas practically all bumper plates will feature a thick and robust layer of rubber on all sides.
Not only will this mean that bumper plates last longer in humid or outdoor environments, but also that they may be dropped or otherwise used more forcefully without risk of chipping or cracking.
Even at bargain-bin levels of quality, it is quite clear that bumper plates will cost more than iron plates - a fact primarily explained by the various methods and materials that go into producing either type of weight plate.
The production of iron weight plates is usually done by pouring molten iron or an iron-containing admixture into molds, wherein it will cool until solid once again, allowing the manufacturer to then coat it in whatever protective substance they may need.
While the core of bumper plates will often follow the same production methods, an additional step or two is added by manufacturers wherein they envelop the metal core in a secondary rubber layer, alongside other quality control methods that ensure the plates are up to standardization.
All this additional work and material will obviously mean that bumper plates will cost more, meaning that iron plates are the more suitable choice for gym owners on a budget.
The aforementioned distinctions between bumper plates and iron plates notwithstanding, there are still several other differences between the two types of weight plates that may play into which kind is the better choice for you.
Because of the fact that iron plates do not have the same rubber coating as bumper plates, it is likely that they will make significant noise when loaded onto a barbell together - or otherwise dropped from a distance, both actions that are commonplace during a workout.
Bumper plates do not have this particular drawback, and are the better choice for individuals that wish to minimize the sound levels of their training session.
Bumper plates and iron plates serve distinctly separate purposes, and it is generally advised that one shouldn’t attempt olympic weightlifting or crossfit with iron plates, as this can lead to damaged equipment and injuries.
As such, if purchasing weight plates for personal use, it is best to match up the type of weight plate with your own personal training goals.
Training programs or sports that involve dropping the plates or otherwise subjecting them to significant impacts should use bumper plates, while iron plates are suitable for all other training modalities.
Bumper plates are almost always shaped in such a way that they can only fit on olympic barbells, or other standardized 2 inch diameter barbells. This means that barbells of larger or shorter peg diameter will not be compatible with bumper plates.
However, this is not the case with iron plates. Because of the less strict standardization of iron plates, it is likely that lifters will find a brand that can fit the barbells that they already own, eliminating the need to purchase a standardized olympic barbell alongside a set of weight plates.
The answer to whether one should purchase bumper plates or iron plates is less simple than one or the other.
Ideally, lifters with the budget and need for it should purchase bumper plates - but, if they do not plan to participate in olympic weightlifting or to subject the plates to harsh conditions, instead purchasing the cheaper iron plates is a perfectly sound decision.
As a final note, the cost/quality ratio is still nonetheless present in either type of weight plate, and it is entirely likely that high quality iron plates can surpass lower quality bumper plates in certain aspects.
1. Chiu, Loren PhD, CSCS. Assessing Weightlifting Bar Mechanical Characteristics. Journal of Strength and Conditioning Research: January 2010 - Volume 24 - Issue - p 1 doi: 10.1097/01.JSC.0000367083.60812.e8
2. Buen, Anders. (2020). Impulse forces and noise from dropped weights on concrete floors. 10.13140/RG.2.2.14930.79049.
3. Lincir, Tom (Summer 2001). "The Making of a Perfect Olympic Plate" (PDF). National Fitness Trade Journal. Retrieved from (https://ivankobarbell.com/press/the_making_of_the_perfect_olympic_plate.pdf) on 21/09/2022