Weight plate#Weight stacks

File:Weightlifting.jpg loaded with plates ranging from 5 to 25 kilograms]]

File:Jednoruční činky.JPG with "standard" plates]]

A weight plate is a flat, heavy object, usually made of cast iron,{{cite web|url=https://www.dickssportinggoods.com/products/cast-iron-weight-plates.jsp|title=Cast Iron Weight Plates|publisher=Dick's Sporting Goods|access-date=20 November 2016|archive-url=https://web.archive.org/web/20171203153910/https://www.dickssportinggoods.com/products/cast-iron-weight-plates.jsp|archive-date=3 December 2017}} that is used in combination with barbells or dumbbells to produce a bar with a desired total weight for the purpose of physical exercise.

Two general categories exist: "standard" plates, which have a center hole of approximately 25 mm (one inch), and "Olympic" plates, meant to fit on the 50 mm (two inches) sleeves of Olympic barbells.{{cite web |url= https://iwf.sport/wp-content/uploads/downloads/2020/01/IWF_TCRR_2020.pdf |publisher= International Weightlifting Federation |page= 48 |title= IWF technical and competition rules and regulations}}{{cite web |url= http://www.livestrong.com/article/1010395-olympic-weights-vs-standard-weights/ |title= Olympic Weights Vs. Standard Weights |first=Kip |last=Doyle |publisher= Livestrong |access-date= 20 November 2016 |archive-url=https://web.archive.org/web/20170729060317/https://www.livestrong.com/article/1010395-olympic-weights-vs-standard-weights/ |archive-date= 29 July 2017}} Standard plates are usually paired with adjustable dumbbells and Olympic plates with full-size barbells, although standard barbells and Olympic dumbbells exist.{{cite web|url=http://www.powerhouse-fitness.co.uk/bodymax-6-ft-standard-spinlock-barbell-with-collars.php|title=Bodymax 6 ft Standard Spinlock Barbell with collars|publisher=Powerhouse Fitness|access-date=20 November 2016|archive-url=https://web.archive.org/web/20170708104352/https://www.powerhouse-fitness.co.uk/bodymax-6-ft-standard-spinlock-barbell-with-collars.php|archive-date=8 July 2017}}{{cite web|url=http://www.troybarbell.com/items.aspx?brand=usa&cat=bar&catnumber=17&item=61 |title=Olympic Dumbbell Handle|publisher=Troy Barbell|access-date=26 February 2018|archive-url=https://web.archive.org/web/20180228041142/http://www.troybarbell.com/items.aspx?brand=usa&cat=bar&catnumber=17&item=61|archive-date=28 February 2018}}

Weight plates may incorporate holes for ease of carrying (called "grip plates") or be solid discs (especially those used for competition). Non-competition plates often have variable diameters and widths, such as on the adjustable dumbbells pictured right, with heavier plates generally being larger in diameter, thickness, or both. Weight plates are typically round, although 12-sided and other polygonal varieties exist.{{cite web|url=http://capbarbell.com/cap-barbell-12-sided-2-cast-iron-grip-plate-gray/|title=CAP 12-Sided Olympic Cast Iron Grip Plate|publisher=CAP Barbell|access-date=20 November 2016|archive-url=https://web.archive.org/web/20170621224333/http://capbarbell.com/cap-barbell-12-sided-2-cast-iron-grip-plate-gray/|archive-date=21 June 2017}} Most plates are coated with enamel paint or hammertone{{Cite web |title=York Olympic Hammertone Cast Iron Weight Plate 1 x 20kg |url=https://www.workoutforless.co.uk/products/york-olympic-hammertone-cast-iron-weight-plate-1-x-20kg |access-date=2022-12-01 |website=Workout For Less |language=en}} to resist corrosion; more expensive varieties may be coated with chrome, rubber, or plastic.{{cite web|url=http://blog.adamantbarbell.com/639/barbell-weight-plates-a-comparison-of-iron-and-rubber-models/|title=Barbell Weight Plates – A Comparison of Iron and Rubber Models|publisher=Adamant Barbell|access-date=20 November 2016|archive-url=https://web.archive.org/web/20161223150917/https://blog.adamantbarbell.com/639/barbell-weight-plates-a-comparison-of-iron-and-rubber-models/|archive-date=23 December 2016}}

Plate sizes

Plates are available in a range of weights. Common Olympic plate (50 mm center hole) denominations are in 1.25, 2.5, 5, 10, 15, 20, and 25 kg sizes,{{cite web|url=http://www.mcsport.ie/p/bodymax-olympic-trigrip-grip-discs/p-wtow0038|title=Bodymax Olympic Trigrip Grip Discs|publisher=McSport, Ireland|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161119064218/http://www.mcsport.ie/p/bodymax-olympic-trigrip-grip-discs/p-wtow0038|archive-date=19 November 2016}} or 2.5, 5, 10, 25, 35, and 45 lbs,{{cite book|author=Stoppani, Jim|title=Jim Stoppani's Encyclopedia of Muscle & Strength, 2E|url=https://books.google.com/books?id=NkiqBAAAQBAJ&pg=PA27|date=1 October 2014|publisher=Human Kinetics|isbn=978-1-4504-5974-7|pages=27–|url-status=live|archive-url=https://web.archive.org/web/20180228042926/https://books.google.com/books?id=NkiqBAAAQBAJ&pg=PA27|archive-date=28 February 2018}} with 0.25, 0.5, and 50 kg,{{cite web|url=http://www.ivankobarbell.com/products/cbpp/|title=Products – CBPP – Ivanko|publisher=Ivanko Barbell Company|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161119062907/http://www.ivankobarbell.com/products/cbpp/|archive-date=19 November 2016}} or 1.25 and 100 lb discs less commonly seen.

Standard plates (25mm center hole) are commonly available in 1.25, 2.5, 5, 10, 15, and 20 kg,{{cite web|url=http://www.elitefitness.co.nz/consumer/product/5481/ezi-grip-standard-weight-plate|title=Elite Ezi-Grip Standard Weight Plate|publisher=Elite Fitness NZ|access-date=26 February 2018|url-status=live|archive-url=https://web.archive.org/web/20170702170244/http://www.elitefitness.co.nz/consumer/product/5481/ezi-grip-standard-weight-plate|archive-date=2 July 2017}} or 2.5, 5, 10, 25, 35 and 50 lb{{cite web|url=https://yorkbarbell.com/product/1-inch-standard-contour-cast-iron-plate/|title=1" Standard Contour Cast Iron Plate|website=York Barbell|language=en-US|access-date=2020-02-04}} where pound denominated plates are used. Less commonly seen are plates of 0.5, 7.5, and 25 kg,{{cite web|url=https://www.viavito.com/weight-training/weight-plates/cast-iron-standard-weight-plates.html|title=Viavito Cast Iron Standard Weight Plates|publisher=Viavito|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161119084716/https://www.viavito.com/weight-training/weight-plates/cast-iron-standard-weight-plates.html|archive-date=19 November 2016}}{{cite web|url=http://www.mcsport.ie/p/bodymax-1-hammertone-weight-discs/p-wtsw0001|title=Bodymax 1" Hammertone Weight Discs|publisher=McSport, Ireland|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161119064117/http://www.mcsport.ie/p/bodymax-1-hammertone-weight-discs/p-wtsw0001|archive-date=19 November 2016}} or 1.25, 7.5, 12.5, 20, and 100 lbs.{{cite web|url=https://www.scribd.com/document/97692068/CAP-Barbell-Catalog|title=CAP Barbell Catalog|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161119121511/https://www.scribd.com/document/97692068/CAP-Barbell-Catalog|archive-date=19 November 2016}}

Bumper plates are commonly available in 5, 10, 15, 20, and 25 kg,{{cite web|url=https://www.roguefitness.com/kg-rogue-bumpers|title=KG Rogue Bumpers|publisher=Rogue Fitness|access-date=7 March 2018|url-status=live|archive-url=https://web.archive.org/web/20170626000619/http://www.roguefitness.com/kg-rogue-bumpers|archive-date=2017-06-26}} or 10, 15, 25, 35, 45, and 55 lb in pound-denominated sets.{{cite web|url=https://www.vulcanstrength.com/Bumper-Plates-s/92.htm|title=Black Training Bumper Plates|publisher=Vulcan Strength|access-date=7 March 2018|url-status=live|archive-url=https://web.archive.org/web/20170905002531/https://www.vulcanstrength.com/Bumper-Plates-s/92.htm|archive-date=5 September 2017}}

Weight accuracy

Low-cost plates can vary widely from their marked weight. A 2% or 3% variation is not uncommon, with plates from some manufacturers frequently being 10% or more over or under (a 45-pound plate can weigh as little as 40 pounds, or as much as 50).{{cite web|url=https://www.garage-gyms.com/steel-powerlifting-weight-plates-discs-guide-review/|title=A Guide to Buying Steel Powerlifting Plates & Discs|date=16 November 2017|publisher=Garage Gyms|access-date=2020-07-30}} Tom Lincir, founder of the Ivanko Barbell Company, has encountered {{convert|45|lb|kg|1|adj=on}} plates weighing as little as {{convert|38|lb|kg|1}}, or as much as {{convert|59|lb|kg|1}}.{{cite journal |title=The Making of a Perfect Olympic Plate |journal=National Fitness Trade Journal |date=Summer 2001 |last=Lincir |first=Tom |url=http://www.ivankobarbell.com/press/the_making_of_the_perfect_olympic_plate.pdf |access-date=2016-11-18 |quote=The worst examples – a plate that weighed 37.5 pounds, and one that weighed 59 pounds. |url-status=live |archive-url=https://web.archive.org/web/20160417020233/http://www.ivankobarbell.com/press/the_making_of_the_perfect_olympic_plate.pdf |archive-date=2016-04-17 }}

Plates can be weighed, and the equipment marked (using a paint pen or other permanent marker) with the true weight.{{cite web|url=https://www.youtube.com/watch?v=V7pVtXPYtGM&t=5m41s|title=The Dumbbell Rack with Mark Rippetoe|last=Starting Strength|date=19 December 2012|access-date=20 November 2016|via=YouTube|url-status=live|archive-url=https://web.archive.org/web/20180228042926/https://www.youtube.com/watch?v=V7pVtXPYtGM&t=5m41s|archive-date=28 February 2018}}

Calibrated plates are available from high-end manufacturers; many advertise these plates as being accurate to within {{convert|10|g|lb|2}} of marked weight, which is the tolerance mandated by the International Weightlifting Federation for plates used in competition.{{cite web|url=http://www.roguefitness.com/rogue-calibrated-kg-steel-plates|title=Rogue Calibrated KG Steel Plates|publisher=Rogue Fitness|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161119060301/http://www.roguefitness.com/rogue-calibrated-kg-steel-plates|archive-date=19 November 2016}}{{cite web|url=http://www.ivankobarbell.com/products/ocb/|title=Products – OCB – Ivanko|publisher=Ivanko Barbell Company|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161119063238/http://www.ivankobarbell.com/products/ocb/|archive-date=19 November 2016}}

Bumper plates

Olympic plates may come in the form of bumper plates, which are made of resilient rubber. These are used for Olympic weightlifting, a category of movements that involve lifting a barbell high overhead, then letting it fall.{{cite web|url=http://www.ironmind.com/articles/jim-schmitz-on-the-lifts/Dropping-Weights/|title=Dropping Weights|first=Jim|last=Schmitz|publisher=IronMind|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161121170346/http://www.ironmind.com/articles/jim-schmitz-on-the-lifts/Dropping-Weights/|archive-date=21 November 2016}}

Their design permits a loaded barbell to be dropped (and to bounce) after a lift, with negligible damage to the floor, plates, and bar.{{cite web|url=http://blog.vulcanstrength.com/2014/02/about-bumper-plates.html|title=About Bumper Plates|publisher=Vulcan Strength Training Systems|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161119061426/http://blog.vulcanstrength.com/2014/02/about-bumper-plates.html|archive-date=19 November 2016}} Unlike most iron plates, where heavier plates have larger diameters, bumper plates are all the same diameter, instead varying in thickness and construction. This helps to distribute the force of the dropped barbell across all the plates more evenly, reducing damage to the equipment.{{cite web|url=https://gymcrafter.com/what-bumper-plates/|title=Are Bumper Plates a Good Choice For a Home Gym in 2021?|website=gymcrafter.com}}

Lower-end bumper plates are generally made of solid rubber with a steel or brass hub. Competition-grade bumper plates are more compact, with a layer of rubber surrounding a steel core.{{cite web|url=http://www.garage-gyms.com/bumper-plates-sets-crossfit-guide/|title=Bumper Plates Sets For Crossfit & Weightlifting – Pricing Guide|date=11 February 2014|publisher=Garage Gyms|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161125121927/http://www.garage-gyms.com/bumper-plates-sets-crossfit-guide/|archive-date=25 November 2016}}{{cite web|url=https://bumperplates.com/bumper-plates-faq/|title=Bumper Plates FAQ|publisher=Bumper Plates for Weightlifters, by Weightlifters|access-date=20 November 2016|archive-url=https://web.archive.org/web/20170716211622/https://bumperplates.com/bumper-plates-faq/|archive-date=16 July 2017}}

Bumper plates used in competition have a diameter mandated by the International Weightlifting Federation of {{convert|450|mm|in|2}} ±{{convert|1|mm|in|2}}, with lighter plates being narrower than heavier plates.{{cite web|url=https://iwf.sport/weightlifting_/equipment/|title=Equipment|publisher=International Weightlifting Federation}}{{cite web|url=http://boxpromag.com/levels-bumper-plates/|title=The Levels of Bumper Plates|date=3 November 2014|publisher=Box Pro Magazine|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161121173503/http://boxpromag.com/levels-bumper-plates/|archive-date=21 November 2016}}{{cite web|url=http://www.beyondthehomegym.com/bumper-plate-guide-crossfit-strength-training/|title=Bumper Plate Guide for CrossFit and Strength Training|date=19 May 2016|publisher=Beyond the Home Gym|access-date=20 November 2016|archive-url=https://web.archive.org/web/20161121105425/http://www.beyondthehomegym.com/bumper-plate-guide-crossfit-strength-training/|archive-date=21 November 2016}} The lightest bumper plates available are generally {{convert|5|kg|lb}}, or {{convert|10|lb|kg}} in pound-denominated sets. Plates lighter than this are generally smaller in diameter and are known as "change plates" when paired with bumper plates.{{cite web|url=http://www.garage-gyms.com/change-plates-review-kg-shopping-guide/|title=Olympic Change Plates Review and Shopping Guide|date=6 July 2015|publisher=Garage Gyms|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161227201034/http://www.garage-gyms.com/change-plates-review-kg-shopping-guide/|archive-date=27 December 2016}}

As an alternative to rubber plates, "technique plates", made of plastic, are available. Technique plates are more expensive than rubber, but hold up better to repeated drops. Their primary purpose is to allow novice lifters to practice Olympic lifts at lighter weights that can put too much lateral stress on single pairs of rubber plates, damaging them.{{cite web|url=http://www.garage-gyms.com/10-pound-bumpers-vs-technique-plates/|title=10-Pound Bumper Plates vs Technique Plates|date=18 February 2015|publisher=Garage Gyms|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161106232710/http://www.garage-gyms.com/10-pound-bumpers-vs-technique-plates/|archive-date=6 November 2016}}

Vinyl plates

Standard (25 mm hole) "vinyl" plates are often sold paired with dumbbells or barbells as a low-cost option for casual strength training. These plates are made of cement or sand coated with a polyvinyl chloride sheath. The cement tends to break down over time and leak out of holes in the sheath, and the weights are less dense than iron so that fewer fit on a given bar.{{cite web|url=http://www.stayfitbug.com/the-fitness-bug/vinyl-weights-or-cast-iron-weights/|title=Vinyl Weights or Cast Iron Weights?|publisher=Stay-Fit Bug|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161119061609/http://www.stayfitbug.com/the-fitness-bug/vinyl-weights-or-cast-iron-weights/|archive-date=19 November 2016}}

Weight stacks

File:WeightStack.JPG; in this example, each plate weighs 6 kg]]

Weight machines commonly use specialized sets of plates (called "weight stacks"), consisting of a set of rectangular plates mounted on rails. Through a cable and pulley system, the burden is transferred to the machine's user. By placing a pin in the stack that causes the cable to pull on each plate above the pin, the weight is selected. We refer to this configuration as a "selectorized" weight machine.{{cite web|url=http://www.empire-fitness-services.com/Fitness-Equipment-Articles/Plate-Loaded-vs-Selectorized-Gym-Equipment.htm|title=Plate Loaded vs. Selectorized Weight Machines|publisher=Empire Fitness Services|access-date=20 November 2016|url-status=live|archive-url=https://web.archive.org/web/20161030173840/http://www.empire-fitness-services.com/Fitness-Equipment-Articles/Plate-Loaded-vs-Selectorized-Gym-Equipment.htm|archive-date=30 October 2016}}

Some weight machines, such as the sled-type leg press, or the Smith machine, are designed to be loaded with Olympic plates instead of using a cable-driven stack.

References

External links

{{commons category-inline|Weight plates}}

Category:Weight training equipment