# Free Weights & Bars

A barbell, dumbbell, kettlebell or plate is defined by how its load attaches and rotates, not by brand. Sleeve and center-hole standards decide which bars and plates fit together; bushings versus bearings decide how fast a bar spins under a fast lift; bell or handle shape decides whether a tool presses or swings.

## How it works

A barbell spreads a load across a long bar so two hands share it, with rotating sleeves that let the bar spin independently of the plates during fast lifts like the snatch. A dumbbell puts the same idea in one hand: either a welded fixed weight, or a handle built to take plates on and off, or a dial/pin that changes how many internal plates lift with the handle. A kettlebell shifts the mass below and in front of the handle instead of around it, which is what suits swinging and ballistic moves rather than straight pressing. Weight plates are the add-on mass for bars and some dumbbells, sized by a center hole that must match the bar's sleeve or handle diameter, and coated in rubber when they are meant to be dropped from overhead.

## How an expert narrows the choice

```mermaid
timeline
  section 1 · Tool type
    dumbbell : ask Dumbbell build, Adjustment mechanism, Dumbbell weight : skip Bar shape, Sleeve size, Shaft diameter, Knurling, Sleeve rotation, Bar weight, Bar finish/coating, Kettlebell build, Bell weight, Plate hole size, Plate material, Diameter behavior, Weight accuracy
    barbell : ask Bar shape, Sleeve size, Knurling, Bar finish/coating : skip Dumbbell build, Dumbbell material, Adjustment mechanism, Weight jump size, Dumbbell weight, Kettlebell build, Bell weight, Plate hole size, Plate material, Diameter behavior, Weight accuracy
    kettlebell : ask Kettlebell build, Bell weight : skip Bar shape, Sleeve size, Shaft diameter, Knurling, Sleeve rotation, Bar weight, Bar finish/coating, Dumbbell build, Dumbbell material, Adjustment mechanism, Weight jump size, Dumbbell weight
    weight_plate : ask Plate hole size, Plate material : skip Dumbbell build, Dumbbell material, Adjustment mechanism, Weight jump size, Dumbbell weight, Bar shape, Sleeve size, Shaft diameter, Knurling, Sleeve rotation, Bar weight, Bar finish/coating, Kettlebell build, Bell weight
  section 2 · Training context
    olympic_or_crossfit : ask Plate material, Sleeve rotation
    powerlifting : ask Sleeve rotation, Knurling
    kettlebell_sport : ask Kettlebell build : skip Dumbbell build, Bar shape
```

1. **Tool type.** Dumbbell, barbell, kettlebell, or weight plate?
   Each tool's defining specs are unrelated: a dumbbell's mechanism, a barbell's sleeve and knurl, a kettlebell's handle and build, a plate's hole and material. This fork decides which facet set applies.
   If dumbbell: ask Dumbbell build, Adjustment mechanism, Dumbbell weight; skip Bar shape, Sleeve size, Shaft diameter, Knurling, Sleeve rotation, Bar weight, Bar finish/coating, Kettlebell build, Bell weight, Plate hole size, Plate material, Diameter behavior, Weight accuracy.
   If barbell: ask Bar shape, Sleeve size, Knurling, Bar finish/coating; skip Dumbbell build, Dumbbell material, Adjustment mechanism, Weight jump size, Dumbbell weight, Kettlebell build, Bell weight, Plate hole size, Plate material, Diameter behavior, Weight accuracy.
   If kettlebell: ask Kettlebell build, Bell weight; skip Bar shape, Sleeve size, Shaft diameter, Knurling, Sleeve rotation, Bar weight, Bar finish/coating, Dumbbell build, Dumbbell material, Adjustment mechanism, Weight jump size, Dumbbell weight.
   If weight_plate: ask Plate hole size, Plate material; skip Dumbbell build, Dumbbell material, Adjustment mechanism, Weight jump size, Dumbbell weight, Bar shape, Sleeve size, Shaft diameter, Knurling, Sleeve rotation, Bar weight, Bar finish/coating, Kettlebell build, Bell weight.
   Skip if already known: a query naming 'dumbbell', 'barbell', 'kettlebell', or 'plate', an earlier answer naming a mechanism, sleeve size, or bell weight.

2. **Training context.** General strength, Olympic lifts/CrossFit, powerlifting, or kettlebell sport?
   Context decides whether drop-tolerance, rotation speed, and calibrated accuracy matter at all, which separates a casual home set from gear that must meet a federation's spec.
   If olympic_or_crossfit: ask Plate material, Sleeve rotation.
   If powerlifting: ask Sleeve rotation, Knurling.
   If kettlebell_sport: ask Kettlebell build; skip Dumbbell build, Bar shape.
   Skip if already known: an earlier answer naming CrossFit, Olympic lifting, powerlifting, or kettlebell competition.

## What to surface

### Tool type

Whether the item is a dumbbell, a barbell (including specialty bars), a kettlebell, or a weight plate. It decides which spec set even applies: a dumbbell's mechanism, a barbell's sleeve and knurl, a kettlebell's build, or a plate's hole and material. Asking this first avoids asking about knurling on a kettlebell or a mechanism on a plate. [1] [4]

Values: dumbbell, barbell, kettlebell, weight_plate.
Question to ask: Dumbbell, barbell, kettlebell, or weight plate?

Used as: top-level split, filter. Data: derived from listing fields, backfill cost low. Look for it as: Derive from the product title and category breadcrumb; these four words almost always appear.
Title keyword match covers nearly every listing.

### Training context

What the buyer mainly trains for: general strength, Olympic weightlifting or CrossFit, powerlifting, or kettlebell sport. Context decides whether drop-tolerance (bumper plates), fast sleeve rotation (bearings), or federation-calibrated accuracy actually matter, versus a home set where none of that is worth the extra cost. [2] [1]

Values: general_strength, olympic_or_crossfit, powerlifting, kettlebell_sport.
Question to ask: General strength, Olympic lifts/CrossFit, powerlifting, or kettlebell sport?

Used as: top-level split, filter. Data: needs research, backfill cost low. Look for it as: Rarely a listed field; inferred from marketed use case ('CrossFit bumper plates', 'powerlifting bar', 'competition kettlebell').
Keyword-match title and category against the four values; default to general_strength when nothing else is named.

### Dumbbell weight

A fixed dumbbell's single marked weight, or a plate-loaded/selectorized dumbbell's full adjustable range, both in pounds. This is the primary spec on every dumbbell listing and spec sheet: it decides whether one pair covers a lifter's whole program or needs replacing as they get stronger, and it is the basis every price-per-pound comparison runs on. [6] [8]

Range: 1 to 150 lb. Fixed dumbbells commonly run 5 to 100 lb per hand; adjustable dumbbells typically top out between 50 and 125 lb.
Question to ask: What dumbbell weight, or adjustable range, do you need?

Used as: filter, shown on the card, sortable. Data: on the listing, backfill cost low. Look for it as: Always in the title and spec table ('50 lb Hex Dumbbell', '5-150 lb Adjustable Dumbbell').
Title/spec-table numeral; use the single weight for fixed_weight and the full min-max range for plate_loaded_adjustable or selectorized_adjustable.
Chart: position on a weight-capacity scale, alongside kettlebell_weight_kg.

### Sleeve size

The diameter of the bar's rotating ends where plates load: standard (1 inch / 25 mm) or Olympic (2 inch / 50 mm). Sleeve size must match the center hole of every plate the buyer already owns or plans to buy; the two standards are not interchangeable without an adapter sleeve. [1] [5]

Values: standard_1in_25mm, olympic_2in_50mm.
Question to ask: Need standard 1-inch sleeves, or Olympic 2-inch?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Named in the title or spec line ('Olympic Barbell', '1" Standard Bar').
Title keyword match; a bar marketed as 'Olympic' or priced like a full-size bar defaults to olympic_2in_50mm.

### Plate hole size

The diameter of the plate's center hole: standard (1 inch / 25 mm) or Olympic (2 inch / 50 mm). This has to match the sleeve or handle it will load onto; an Olympic plate will not fit a standard bar and vice versa, so it is the first compatibility check before weight or material. [5] [1]

Values: standard_1in_25mm, olympic_2in_50mm.
Question to ask: Standard 1-inch holes, or Olympic 2-inch?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Named in the title ('Olympic Plate', 'Standard Weight Plate').
Title keyword match; plates sold alongside a full-size bar default to olympic_2in_50mm.

### Dumbbell build

Whether the dumbbell is a fixed welded weight, a plate-loaded (adjustable) handle, or a selectorized dumbbell that changes weight via a dial or pin. Fixed dumbbells are fastest to pick up and swap in a gym with a full rack; plate-loaded and selectorized trade that speed for one pair covering a wide range in a fraction of the floor space. [3]

Values: fixed_weight, plate_loaded_adjustable, selectorized_adjustable.
Question to ask: Fixed dumbbells, or adjustable to save space?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Almost always in the title ('Adjustable Dumbbell', 'Selectorized', 'Hex Dumbbell').
Title keyword match; default to fixed_weight when the title names only a weight and material.

### Kettlebell build

Whether the kettlebell is a traditional cast-iron bell, whose body and handle grow larger as the marked weight increases, or a competition-style steel bell built to one fixed external size and handle diameter at every weight. Technique carries over cleanly between weights on a competition bell because the grip never changes size; on a cast-iron bell, moving up a size also means relearning the rack and grip, since a heavier bell is a physically bigger bell. [4] [7]

Values: cast_iron_traditional, competition_steel_standardized.
Question to ask: Classic cast iron, or same-size competition style?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Usually in the title ('Competition Kettlebell', 'Cast Iron Kettlebell').
Title keyword match; default to cast_iron_traditional when the title says only 'kettlebell' and a material.

### Plate material

What the plate is made of: bare cast iron, rubber-coated bumper, calibrated steel, cement-and-vinyl, or lightweight plastic technique plates. Only bumper and technique plates are built to be dropped from overhead without damaging the floor or the plate; bare iron and vinyl plates are cheaper but are meant to be lowered under control, not released. [5]

Values: bare_cast_iron, rubber_bumper, calibrated_steel, vinyl_cement_filled, technique_plastic, unspecified.
Question to ask: Rubber bumper plates, cast iron, or vinyl?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Usually in the title ('Bumper Plate', 'Cast Iron Plate', 'Vinyl Weight Plate').
Title keyword match against the five material names.
Chart: position on a drop-tolerance axis, bumper and technique plates highest.

### Bar finish/coating

What the barbell's shaft and sleeves are finished with: black oxide, chrome, zinc, e-coat, Cerakote, or stainless steel. Black oxide grips best but rusts fastest and needs oiling; chrome and zinc resist rust better but can feel slicker chalked; Cerakote adds the most corrosion resistance and comes in colors but costs more. [9] [10]

Values: black_oxide, chrome, zinc, e_coat, cerakote, stainless_steel, unspecified.
Question to ask: Which bar finish: black oxide, chrome, zinc, or Cerakote?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Named in the title or variant selector ('Black Oxide', 'Cerakote', 'Chrome', 'Black Zinc').
Title/variant keyword match against the finish names; default to black_oxide for a plain 'Olympic Barbell' title with no finish named.
Chart: position on a rust-resistance/grip-feel axis, black oxide grippiest, chrome and Cerakote most rust-resistant.

### Bar shape

The bar's shape and intended lift: a straight Olympic bar, a powerlifting bar, an EZ curl bar, a trap/hex bar, a safety squat bar, a multi-grip Swiss bar, or a short fixed barbell. Shape changes which joint position and lift the bar is built for: EZ curl's camber eases the wrist on arm work, a trap bar moves the load's center of gravity closer to the lifter for deadlifts, and a safety squat bar pads and cambers the load to spare a stiff shoulder. [1]

Values: straight_olympic, powerlifting_bar, ez_curl, trap_or_hex, safety_squat, swiss_multigrip, fixed_barbell.

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Named directly in the title ('Trap Bar', 'Safety Squat Bar', 'EZ Curl Bar'); a plain 'Olympic Barbell' title defaults to straight_olympic.
Title keyword match against the seven shape names.

### Dumbbell material

What a fixed dumbbell's weight is made of and coated with: bare cast iron, rubber or neoprene coated, urethane coated, chrome, or a cement-filled vinyl shell. Bare iron is cheapest but chips floors and rusts; rubber or urethane protects floors and quiets drops at a price step up; cement-filled vinyl is the lightest-duty option and can crack and leak over time. [3]

Values: bare_cast_iron, rubber_or_neoprene_coated, urethane_coated, chrome, vinyl_cement_filled, unspecified.
Question to ask: Bare iron, rubber-coated, or urethane?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Usually in the title ('Rubber Hex Dumbbell', 'Urethane Dumbbell', 'Vinyl Dumbbell').
Title keyword match; default to bare_cast_iron for plain 'cast iron dumbbell' titles.
Chart: position on a floor-protection/noise axis, coated materials higher.

### Adjustment mechanism

How a plate-loaded or selectorized dumbbell changes weight: a spin-lock collar, a spring or compression collar, a turn dial, a sliding pop-pin, a selector pin, or a switch. Spin-lock and sliding collars are cheap and simple but slow between sets; dial and pin mechanisms change weight in seconds for circuits and supersets but cost more and add a point of mechanical failure. [3] [6]

Values: spin_lock_collar, spring_or_compression_collar, turn_dial, pop_pin, selector_pin, switch, not_applicable.

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Usually named in the title or bullet points ('Dial Adjustable', 'Quick-Lock', 'Selector Pin').
Title keyword match against the six mechanism names; only applies when dumbbell_type is not fixed_weight.
Chart: position on a changeover-speed axis, dial and pin fastest.

### Weight jump size

How big a step the dumbbell's adjustment takes: fine (about 2.5 lb), standard (about 5 lb), or coarse (10 lb or more, sometimes needing an offset trick for a finer step). A fine jump lets a lifter progress in small amounts on isolation moves; a coarse jump is fine for compound lifts but can force skipping a size that would have been the right next step. [6]

Values: fine_about_2_5lb, standard_about_5lb, coarse_10lb_or_more, not_applicable.
Question to ask: Fine, standard, or coarse weight jumps?

Used as: filter, shown on the card. Data: needs research, backfill cost medium. Look for it as: Often a separate spec line ('Weight Increments: 5 lb') rather than in the title.
Check the spec table on the brand page; selectorized models frequently offer two increment options by moving one dial versus two.
Chart: position on a progression-granularity axis.

### Knurling

The crosshatch texture cut into the bar's grip sections, and whether it includes a center band: center-knurled, no center knurl, or an unusually aggressive or passive cut. A center knurl bites the upper back for a stable high-bar or low-bar squat but can scrape the chest or thighs on bench and deadlift days; the women's Olympic bar skips it for that reason. [1] [2]

Values: center_knurl, no_center_knurl, aggressive_knurl, passive_knurl, unspecified.

Used as: filter, shown on the card. Data: needs research, backfill cost medium. Look for it as: Sometimes in bullet points ('center knurl', 'no center knurl'); otherwise check the brand spec sheet.
Default straight Olympic and powerlifting bars to center_knurl; default bars marketed as 'women's' to no_center_knurl.

### Bar weight

The barbell's own weight before any plates are added. This is the floor of every lift: a 20 kg men's Olympic bar and a 15 kg women's bar are the two benchmarks lifters calibrate warm-up jumps against, and a heavier specialty bar changes that math before a single plate goes on. [1] [2]

Range: 15 to 20 kg. 20 kg for a men's/general Olympic or powerlifting bar, 15 kg for a women's Olympic bar; safety squat and other specialty bars can run heavier.

Used as: shown on the card, sortable. Data: on the listing, backfill cost low. Look for it as: Usually stated directly ('20kg Olympic Barbell') or inferable from sleeve_standard and barbell_specialty_type.
Default straight Olympic bars to 20 kg unless titled 'women's bar', which defaults to 15 kg.
Chart: position on a bar-weight scale.

### Bell weight

The kettlebell's total marked weight. Because the bell's mass sits below and past the hand, a given kettlebell weight swings and racks harder than the same number on a dumbbell, so the usable range for most lifters is narrower than their dumbbell range. [4] [7]

Range: 4 to 48 kg. Home sets commonly run 8 to 32 kg; competition-colour-coded bells are sold from 8 to 48 kg in fixed steps, and cast-iron sets go up to about 48 kg.

Used as: shown on the card, sortable. Data: on the listing, backfill cost low. Look for it as: Stated directly in the title and almost always stamped on the bell itself.
Title and image both carry the number; rarely missing.
Chart: position on a bell-weight scale.

### Diameter behavior

Whether the plate's outer diameter grows as its marked weight increases (iron plates) or stays fixed at every weight (bumper plates). Bumper plates are built the same 450 mm diameter at every weight from 10 kg up specifically so a loaded bar lands evenly and predictably when dropped; an iron-plate set gives no such guarantee since a heavier plate is simply bigger. [5] [1]

Values: uniform_diameter_bumper, grows_with_weight_iron.

Used as: shown on the card. Data: derived from listing fields, backfill cost low. Look for it as: Not a listed field; derive from plate_material_construction (bumper implies uniform, cast iron implies grows_with_weight).
Pure derivation from the material facet; no separate lookup needed.
Chart: position on a drop-size-consistency axis.

### Shaft diameter

The diameter of the bar's center grip section, distinct from the thicker sleeve ends. A thinner shaft (around 25 mm) is easier for smaller hands to close around and flexes more under load; a thicker shaft (toward 29 mm) is stiffer and favored where federation rules require it. [1] [2]

Range: 25 to 29 mm. 25 mm on the women's Olympic bar, 28 mm on the men's Olympic bar; powerlifting-federation bars run 28 to 29 mm.

Used as: shown on the card, sortable. Data: needs research, backfill cost medium. Look for it as: Usually a separate spec line, not in the title; rarely on generic retail listings.
Check the brand spec sheet; when absent, infer 28 mm for a men's/general Olympic bar and 25 mm for a women's bar from the title.
Chart: position on a stiffness/grip-thickness scale.

### Sleeve rotation

What lets the bar's sleeves spin independently of the shaft: simple bushings, or needle or ball bearings. Bearings spin faster and smoother, which Olympic lifts need so the plates keep still while the bar turns under a fast catch; bushings rotate more slowly but are simpler and more robust under the heaviest static loads, which is what powerlifting needs instead. [1]

Values: bushings, needle_bearings, ball_bearings, unspecified.

Used as: filter, shown on the card. Data: needs research, backfill cost medium. Look for it as: Usually a spec line ('bushing', 'bearing') rather than in the title; most brand pages this run were unreachable behind a bot-check, so treat as researched, not listing.
Default powerlifting-marketed bars to bushings and Olympic-weightlifting-marketed bars to bearings absent a stated spec.
Chart: position on a spin-speed axis, bearings fastest.

### Weight accuracy

Whether the plate is an ordinary retail plate, which can run several percent off its marked weight, or a calibrated plate certified within a tight tolerance of it. Budget plates from some makers have been measured 10% or more off their stamped weight; competition-calibrated plates are held within about 10 grams of the mark, which matters once a lifter is chasing exact percentages of a max. [5]

Values: uncalibrated_retail, calibrated_competition_grade.

Used as: filter, shown on the card. Data: needs research, backfill cost medium. Look for it as: Not reliably on generic retail listings; named in the title only for dedicated calibrated-plate products ('Calibrated Steel Plates'), otherwise check the brand spec sheet.
Default to uncalibrated_retail unless 'calibrated' or 'competition' appears in the title.

## Numbers worth computing

| Metric | Formula | Why |
|---|---|---|
| Cost per pound of load | `price divided by the item's total marked weight in pounds` | Reviewers compare dumbbells and kettlebells this way because sets and single bells of very different total weight are otherwise hard to price against each other. [6] [7] |

## What you give up

- Bearings let an Olympic bar's sleeves keep spinning while the shaft stops, which fast catches need; powerlifting bars use plainer bushings instead because they only have to survive a heavy, slow lift, not spin fast. [1] Board branch: "Faster spin, less brute durability".
- A dial or pin dumbbell replaces up to 15 or more pairs of fixed dumbbells in one footprint, but every weight change takes a few seconds at the mechanism instead of none at all. [6] Board branch: "More range per pair, slower changeover".

## Words you will meet

- **Knurling**. The crosshatch texture cut into a bar or handle's grip section so hands do not slide.
- **Whip**. A bar's ability to flex and store energy during a lift, then spring back as the lift finishes.
- **Sleeve**. The thicker, rotating end section of a barbell that plates slide onto.
- **Bushing**. A simple metal sleeve that lets a bar's ends rotate; sturdier but slower-spinning than a bearing.
- **Bearing**. A rolling mechanism in a bar's sleeve that lets it spin faster and more smoothly than a bushing.
- **Bumper plate**. A solid rubber-coated plate built to be dropped from overhead without damaging the floor or itself.
- **Calibrated plate**. A plate certified accurate to within a tight tolerance, usually about 10 grams, of its marked weight.
- **Center knurl**. A knurled band across the middle of a barbell's shaft, gripped by the upper back during a squat.
- **Selectorized**. An adjustable dumbbell mechanism that changes weight by turning a dial or moving a pin, without handling loose plates.
- **Spin-lock collar**. A threaded nut that screws onto a plate-loaded bar or dumbbell handle to hold the plates in place.
- **Rack position**. Resting a kettlebell or bar against the forearm and chest between reps instead of holding it out.
- **Kettlebell sport**. A timed competition sport judged on repetitions of set kettlebell lifts, also called girevoy sport.
- **EZ curl bar**. A barbell with a cambered, wavy grip section that eases wrist strain on arm exercises.
- **Trap bar**. A hexagonal frame bar the lifter stands inside, used mainly for deadlifts and shrugs; also called a hex bar.
- **Technique plate**. A lightweight plastic plate sized like a bumper plate, used to practice lifts without real weight.
- **Safety squat bar**. A specialty barbell with padded, cambered yoke pads that rest on the shoulders and shift the load forward, sparing a stiff shoulder.
- **Swiss bar**. A specialty barbell with several parallel handles at different widths and angles, used for pressing and rowing variations; also called a multi-grip bar.
- **Spring or compression collar**. A clip or ring that squeezes shut around a plate-loaded bar or dumbbell handle to hold plates without a threaded nut.
- **Pop pin**. A spring-loaded pin on a plate-loaded dumbbell handle that slides through holes to lock plates at a chosen weight.

## Where we made a call

- Calibrated plates hold about 10 g of their marked weight; uncalibrated retail plates can run several percent off. (confidence medium). Single-sourced to Wikipedia's citation of the IWF tolerance and a plate-maker's account of wide variance; independent brand spec sheets were blocked by bot-checks this run. [5]

## References

1. [Barbell](https://en.wikipedia.org/wiki/Barbell) (primer). Supports: Men's Olympic bar: 20kg, 2.2m, 50mm sleeves, 28mm shaft, 1.31m grip section; Women's Olympic bar: 15kg, 2.01m, 25mm shaft, no center knurl; IPF powerlifting bar: 28-29mm diameter, knurling not chromed; Safety squat bar up to 29kg, up to 35mm grip diameter; Olympic plates 10kg and up are 450mm diameter; EZ curl, trap/hex, safety squat, and Swiss bar shapes and purposes; Powerlifting bars use simpler bushings; need not rotate as fast as Olympic bars.
2. [Olympic weightlifting](https://en.wikipedia.org/wiki/Olympic_weightlifting) (primer). Supports: Men's bar 20kg/28mm shaft/2200mm; women's bar 15kg/25mm shaft/2010mm; 1310mm sleeve spacing; Men's bar has center knurl, women's does not; Bumper plates 10-25kg in 5kg steps with IWF color coding.
3. [Dumbbell](https://en.wikipedia.org/wiki/Dumbbell) (primer). Supports: Three dumbbell types: fixed-weight, plate-loaded adjustable, selectorized adjustable; Fixed dumbbells: cast iron, sometimes rubber/neoprene coated, or concrete-filled plastic shell; Plate-loaded collars: spin-lock, spring collar, compression ring, quick-lock; Selectorized mechanisms: block, dial, glide, twist type.
4. [Kettlebell](https://en.wikipedia.org/wiki/Kettlebell) (primer). Supports: Kettlebell defined as cast-iron or cast-steel ball with a handle; Parts: handle, corners, horns, window, bell, base; Competition color coding by weight, pink 8kg up to gold 48kg.
5. [Weight plate](https://en.wikipedia.org/wiki/Weight_plate) (primer). Supports: Standard plates ~25mm center hole; Olympic plates fit 50mm sleeves; Bumper plates are all the same diameter regardless of weight, unlike iron plates; Competition bumper plate diameter 450mm +/-1mm, IWF mandated; Vinyl plates: cement/sand filled with PVC sheath, low-cost; Technique plates: plastic, more drop-durable than rubber, for novices; Calibrated plates accurate within 10g per IWF competition tolerance; budget plates can run 10%+ off.
6. [Tested By Fitness Experts: 10 Best Adjustable Dumbbells (2026)](https://garagegymreviews.com/best-adjustable-dumbbells) (specialist review). Supports: Adjustment mechanisms compared across models: pop-pin, dial, selector pin, Lock-N-Load switch, spin-lock; Weight increments typically 5lb or 10lb, some models offering a 2.5lb offset option; Handle widths observed from 29mm to 36mm across tested models.
7. [Expert-Tested: Best Kettlebells (2026)](https://garagegymreviews.com/best-kettlebells) (specialist review). Supports: Competition kettlebells have a uniform 35mm handle at every weight, matching the competition standard; Cast iron kettlebells have handle sizes that vary with weight; Tested weight ranges span roughly 4kg to 48kg across reviewed sets (Giant Lifting V3: 4-48kg); Price-per-pound comparisons used to compare sets of different total weight.
8. [Best Dumbbells, Tested and Reviewed (2026)](https://garagegymreviews.com/best-dumbbells) (specialist review). Supports: Weight-range spec row on every reviewed fixed dumbbell, from 1-120 lbs up to 12.5-150 lbs across products; Weight range listed as the primary comparison spec alongside price, material, and handle design.
9. [The Ohio Bar - Black Oxide](https://www.roguefitness.com/rogue-ohio-bar) (spec sheet). Supports: Offers Black Oxide, Black Zinc, E-Coat, and Cerakote finish options; Black Oxide has lower oxidation resistance than the others.
10. [Best Barbells](https://barbend.com/best-barbells/) (specialist review). Supports: Lists 'Coatings' as a standard spec row on every bar reviewed: Hard Chrome, Cerakote, E-Coat, Black Zinc, Stainless Steel.