Amazon IR91042-RP-4x10LB Weight Plates
- Plate
- 4
- Cast Iron
- charcoal
- Better rated than 77%
- More reviewed than 67%
A basic 40 pound cast iron plate set for stacking onto a barbell or machine, worth it once you have confirmed the hole size fits your equipment.
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How it ranks among the 114 plates we track
4.8★ across 379 Amazon ratings, Bayesian-smoothed toward the category average.
379 Amazon ratings, weighted on a log scale so huge counts don't drown everything.
1,000+ bought on Amazon last month.
Brand identity, imagery, description and spec coverage.
The ProductDome score is separate from the Amazon rating shown above: it combines the Bayesian-smoothed Amazon rating with evidence volume, tracked demand, and data quality across the 114 plates we track - how the scorecard works · full plates data report. Confidence: high - strong rating volume and complete data.Last refreshed Aug 4, 2026. Data-computed, not a hands-on test. Compiled by the ProductDome Research Team.
Overview
The IR91042-RP-4x10LB is a four piece set of cast iron weight plates from Amazon, finished in charcoal grey. Each plate weighs 10 pounds per the model designation, making a 40 pound bundle for building out a barbell or plate loaded machine.
Cast iron plates like this are the plain building block for a home gym rack: no bounce, no rubber coating smell, just raw weight to stack in 10 pound increments. The listing does not state the center hole diameter, so it is worth confirming that matches your bar or machine before ordering.
- Charcoal grey color
- Four piece plate set
- 10 pounds per plate
- Cast iron material
Who it's for
Suits someone assembling a barbell load out at home and adding weight in 10 pound steps, or filling out a plate loaded machine that takes standard iron plates. Not for anyone who wants a rubber coated or bumper plate meant to be dropped on a hard floor.
Strengths and trade-offs
Drawn from this product's published specifications.
- Solid cast iron construction
- Charcoal finish resists scuffing
- Four plates cover a 40 pound add-on
- Hole diameter not specified
- No rubber coating to protect floors
Performance notes
Cast iron plates hold their rated weight consistently since there is no foam or rubber layer to compress or wear down over time, and the charcoal coating resists handling scuffs better than bare iron. Fit against a bar or machine comes down to the center hole diameter, which is not listed here, so it is worth checking before the plates arrive.
Specifications
| Brand | Amazon |
|---|---|
| Model | IR91042-RP-4x10LB |
| Pieces | 4 |
| Material | Cast Iron |
| Color | charcoal |
| Item Weight | 2.49 pounds |
How it compares
This product against the closest alternatives we track in plates.
| Product | Amazon rating | Ratings | ProductDome score |
|---|---|---|---|
| Amazon IR91042-RP-4x10LB Weight PlatesThis product | 4.8 / 5 | 379 | 4.3 / 5 |
| CAP OPHWIS-010 Weight PlatesCAP | 4.7 / 5 | 15,711 | 4.5 / 5 |
| RitFit Weight Plates for BarbellRITFIT | 4.8 / 5 | 1,565 | 4.4 / 5 |
| EVERYMATE 1.25LB Change Plates Set Weight PlatesEVERYMATE | 4.8 / 5 | 1,448 | 4.4 / 5 |
| JFIT 20-6650-pr Weight PlatesJFIT | 4.7 / 5 | 777 | 4.3 / 5 |
Similar plates from other brands
Questions about the Amazon IR91042-RP-4x10LB
Common buyer questions answered straight from the product spec data - no fluff, no "it depends".
What is the weight of each plate in the Amazon IR91042-RP-4x10LB set?
The model number indicates 10 pounds per plate across four pieces, for a 40 pound total set.
What material are these plates made from?
Cast iron, per the listed attributes.