Table of contents
Calibrated plate introduction
As we know, calibrated plates are preferredpowerlifting community, mainly due to the extreme weight being lifted and the required accuracy of that weight on the lifter's barbell.
The sport of powerlifting itself did not become mainstream until the 1950s, where it emerged from "uneven lifts." Odd lift competitions consisted of a large number of exercises, with each exercise having a 'three attempt' format. You can read more about the history of strength sportsher.
Bob Hoffman of the York Barbell Company organized and financed the first unofficial World Powerlifting Championships in 1971. Only two countries participated: the United States and Great Britain. Other countries seemed reluctant to compete due to inconsistencies with the rules and format of the competition.
In 1972, representatives from competing countries came together to standardize the rules and encourage better participation and formed the International Powerlifting Federation. Despite regular regional, national and international competitions, calibrated plates were not used in a competitive setting until the mid-1980s.
This was because it had become clear that there were irregularities with what the competitors had removed.
In 1975, Don Reinhoudt had set a world record in the squat, bench and deadlift totaling 1098 kg / 2420 lbs. However, this was later downgraded to 1084.5 kg/2391 lbs. When weighing the equipment used, there was an inconsistency of 13.5 kg/29.7 lb, meaning the plates or barbell were not accurate in weight.
In 1982, Mike Bridges competed in his class with a total weight of 901.8 kg. This was later upgraded to the correct total of 308.8 kg/1999 lbs.
The above examples show that the discrepancies can have a huge impact on a lifter's combined total, potentially making the difference between winning and losing a competition and actually setting a world record.
This is why today the IPF has strict rules regarding equipment that can be used for their competitions, requiring all equipment to either be IPF specification (for national and regional competitions) or IPF approved for international level competitions.
Calibrated plates versus regular weight plates?
Calibrated plates are thinner and more accurate to the indicated weight compared to regular weighing plates.
Calibrated plates are typically used by people who lift a large amount of weight in a competitive environment, such as powerlifting or weightlifting.
There are two types of calibrated plates, those made of cast iron and those made of machined steel, but first let's talk about some of the different types of weight plates available on the market.
Bumperplaten
Bumper plates are typically used by people who enjoy high-impact workouts such as weightlifting, movements such as cleans and jerks, and have also become popular among the CrossFit community.
Often made of solid rubber, with a metal collar in the middle that allows it to fit an Olympic barbell. Although they have the advantage of being made of rubber, this does not make them unbreakable.
Due to the abuse they are susceptible to when dropped overhead onto a solid floor, inferior bumpers can sometimes begin to crackcowsResulted inhalterimbalance when resting on the floor.
Bumpers are notable because they generally always have the same diameter, with only the thickness changing. Popular because they are easy to handle and because they are not made of iron, they make much less noise when dropped.
The weight accuracy of bumpers is generally about 2 to 3% above or below the stated weight of the plates and can be as high as 10% in more extreme cases.
When using these plates you are unlikely to notice the difference unless you are using a large number of plates at one time, where the weight difference can add up.
Standard weight plates
These are good forAt homegyms and beginners who use less weight. They are generally made of cast iron with a 1-inch diameter center hole, which means they will not fit your Olympic barbell.
They are cheaper than most other plates and are manufactured using a cast iron mold, after which the finished plate is finished with a powder coating or rubber coating.
Unlike bumpers, they vary in both diameter and thickness. As with the bumper plates, the accuracy of the plate can decrease by a few percent, but as with the bumpers, this is usually not noticeable when you lift a lower weight.
Olympic halter schijven
The most popular type of plate for gyms, they are manufactured with a 2-inch diameter center hole, meaning they fit Olympic bars like most other barscommercial dumbbellsand plate-filled equipment.
They are made from a variety of materials and are available in cast iron, which can be coated with rubber or urethane. The rubber and urethane coatings tend to be more popular than bare iron as they provide additional protection against floor damage, with urethane being a better quality coating that will last longer.
Calibrated cast iron plates
Cast iron plates are usually made with a sand-cast mold. The mold, in the form of a plate, is filled with sand and then molten scrap metal is usually poured into it. By using scrap, these types of plates are much cheaper to produce.
Cast iron plates usually have small air pockets, this is due to the different types of metals used and the process of pouring molten metal into a mold. This means that the plate is much less accurate than a plate made of solid steel.
When the slabs are cast, they typically have two 'pockets', also called calibrated plugs. The plugs are filled with lead, the lead ensures that the plate reaches the necessary weight and is calibrated, as lead is much denser than steel.
However, there have been cases where the calibrated connectors became loose and fell out. In this case you are left with the tolerance of a cast iron plate, which is not very accurate!
The finished sheet is then powder coated, usually in the color corresponding to the weight, i.e. red to indicate 25 kg or 55 lbs. The reason you are unlikely to see a cast iron plate finished with a coating such as nickel is because they have a poor surface finish. Powder coating provides a much thicker coating that hides these defects. A finish like nickel would actually accentuate them and make them much more difficult to make.
Calibrated steel plates
Machine-calibrated steel plates are produced using a lathe. A lathe is a machining tool used to shape metal using various methods such as cutting, knurling, turning, drilling, etc.
A solid steel disk is set up in a lathe. The lathe cuts away the surface of the steel disc and forms it into shape. They are weighed and the programs are adjusted according to the density of the disk, which changes from batch to batch of material.
Because they are precision machined, no additional materials need to be added.
Each plate is then finished with a zinc or nickel coating to provide the plates with a layer of protection against the elements to help prevent rust. In terms ofKustom Kit Calibrated plateswe use a nickel coating because this is a superior coating than zinc.
What are calibrated plates
Calibrated plates are weighing plates that are very accurate in relation to the indicated weight. They are preferred by those who lift a significant amount of weight and need to ensure that the weight load is equal on both sides of the barbell.
When something is calibrated, including a scale, it means it has been adjusted for precision. For example, a thermometer can be calibrated to give an accurate temperature reading. A weight plate can be calibrated to obtain an accurate weight.
When it comes to accuracy, calibrated plates are very accurate and the weight of each plate should be 0.25% or 10 grams (whichever is easier). That is why they are called calibrated. Calibrated plates are also often thinner compared to bumper and Olympic plates.
Are calibrated plates worth it?
If you lift a lot of weight, calibrated plates are definitely worth it. They are thinner, which allows you to fit more plates on a barbell, and they are more precise, which distributes the weight load evenly.
If you load a 50 lb bumper plate on each side of your barbell, you won't necessarily notice a weight imbalance while squatting, bench pressing, or deadlifting. But if you load four 25kg plates on each side, you would expect to be able to lift 200kg (excluding bars and collars). However, the reality is that there can be a significant difference:
Based on an accuracy of 3% of each 25 kg bumper plate, the total weight can vary between 194 kg and 206 kg, distributed unevenly across your barbell.
In the worst case, the weight difference, based on a 10% accuracy of each 25 kg bumper plate, could be as much as 180 to 220 kg, again unevenly distributed across your barbell.
This would be very noticeable when lifting! In short, accuracy becomes more important the more you lift.
If you load 200 kg of calibrated plates onto your barbell, you are essentially lifting 200 kg in one point.
When it comes to plate thickness, the benefits are once again noticed by those who lift large amounts of weight.
When the plates are thinner, the user can place more plates on the barbell and the weight stays closer to the center of the bar.
This is beneficial for squats and deadlifts because it helps reduce whiplash. Fewer whiplashes ensure that the user remains more stable, making the exercise safer to perform.
What do the different colors on calibrated plates mean?
Calibrated plates have different colors to help identify weight. This is important in a competitive environment when:power lifterhas a beam full of plates, the three judges can easily calculate the weight of the beam. The colors are as follows:
- 25 kg plate / 55 lb plate – Red plate
- 20 kg plate/44 lb plate – Blue plate
- 15 kg plate / 33 lb plate – Yellow plate
- 10 kg plate / 22 lb plate – Green plate
- 5 kg board / 11 lb board – White board
- 2.5kg plate / 5.5lb plate – Black plate
Although we mentioned lbs above, it is important to note that currently calibrated competition plates are only available in kg.
Although most, if not all, calibrated cast iron plates are powder coated, some solid steel plates have a groove around the diameter of the plate, which is painted in the corresponding color. Some steel plates are not color coded, so these would not be suitable for a competition environment.
Are all calibrated plates the same?
At first glance they may look the same, with minor aesthetic differences, but there are some factors that mean that calibrated weight plates are not all the same.
A quick Google search and viewing of images will show a number of plates, many of which look virtually identical save for their brand names.
Much of this is manufactured and distributed from the same factories in the Far East. The only difference may be the cost, with lesser-known brands charging less for the same product.
Some manufacturers produce stainless steel plates. These types of plates do not require coating as they have much higher corrosion resistance compared to cast iron or solid steel plates. However, this depends on the quality of the stainless steel used.
It is also worth noting that stainless steel contains much less carbon than mild steel. This means it has a lower yield point, making these plates more susceptible to dents, but corrosion resistance is higher, which is great for those who live near the ocean!
Different brands of planks also use different finishes depending on the material they are made of.
The most common calibrated plates are completely powder coated, usually in the color corresponding to the weight. For example, a 25 kg/55 lb sheet would be powder coated red. This offers two advantages.
Firstly, it helps to identify the weight of the plate, which is important in a competitive environment
Secondly, it hides errors from the production process and prevents the plates from rusting.
Powder-coated plates are usually imported from the Far East and are all made of cast iron.
The machined solid steel plates, if machined correctly, look much nicer before any finishing is applied. This makes various options possible, from powder coating to galvanizing and nickel plating.
Machined sheet metal with a high-gloss, chrome-like appearance is becoming more common and now imported 'copies' are starting to hit the market.
However, it is worth noting that steel plates offer two different finishes. One is zinc and the other is nickel.
What is the difference between zinc and nickel plated plates?
Galvanizing is a sacrificial coating applied to a metal surface, iron or steel, to protect it from rust.
By sacrifice we mean just that, so over time the zinc will eventually wear away and expose the metal underneath.
When this happens, the metal will need to be painted over. Zinc is a cheaper finish that is not as bright and shiny as nickel, so it doesn't look as luxurious.
Zinc plating is a common finish for small hardware items such as nuts and bolts. There are some calibrated plates that are galvanized and at first glance look like nickel plated plates, but zinc has a much inferior surface finish.
Zinc will likely be the preferred finish as it is much more cost effective. It is worth noting that once the zinc has worn off, you will need to repaint your plates to extend their life.
Nickel plating is not a sacrificial coating, but a decorative finish that is very durable in comparisonUnpleasantzinc. This means better protection of the underlying metal, not only against wear, but also against corrosion.
Are calibrated plates harder than Olympic plates?
Calibrated plates are no harder than Olympic weight plates.
The physical strength of the calibrated plate depends on whether it is made of solid steel or cast iron.
Cast iron is much more brittle than solid steel, making it a material that is much more likely to crack or split. Although iron is a very hard metal, it breaks easily compared to steel, which has a higher tensile strength, meaning it can withstand higher loads than iron.
FAQ
Are calibrated records noisier?
Thinner plates resonate more during use, making them noisier compared to bumper or Olympic plates. This sound can be further accentuated in a commercial fitness environment where plates and bars bang against each other.
There is also a difference in sound when comparing cast iron and solid steel powerlifting plates.
Steel calibrated plates will be much noisier when in use compared to cast iron. This is mainly due to atoms in the material. Iron atoms in solid steel have a tightly packed structure (which is why steel plates are thinner than cast iron) and as such will rub against each other on impact and cause vibration.
In the cast iron plates, they contain a much larger amount of carbon, which disrupts the tightly packed structure. This means that they vibrate less and therefore make less noise. The air pockets formed during the production of iron plates also help reduce noise, but the downside is that it makes these plates more brittle and more likely to break under heavy impacts.
Why do calibrated plates feel heavier?
Calibrated plates, by design, offer higher weight accuracy compared to Olympic plates, which can make them feel heavier. This is for one of two reasons. First, your calibrated plates are actually heavier than standard plates. Second, the density is squeezed into a much smaller surface area, creating the illusion of a heavier weight.
Imagine trying to pick up a tennis ball that weighs 25 kg, that would be extremely difficult.
Kristen From a competitive powerlifting background and training at local and national competitions, I quickly developed an interest in designing training equipment that was robust, functional and tailored to the more extreme user. I founded Kustom Kit in 2013 and continue to innovate the fitness equipment market by designing, manufacturing and shipping equipment from our factory here in Somerset, UK. View all messages Latest posts Reverse Lunges Deficiency: 5 Worst Exercise Form Mistakes 7 Best Butt Stretches for Lower Back Pain Relief
