FLEX 24V Brushless Cordless 6-1/2-Inch In-Line vs Ryobi One P505 18V Lithium Ion Cordless 5 1/2"
Updated July 2026 — FLEX 24V Brushless Cordless 6-1/2-Inch In-Line wins on price and weight, Ryobi One P505 18V Lithium Ion Cordless 5 1/2" wins on rpm.
The FLEX offers superior cutting performance and advanced features, while the Ryobi is a budget-friendly option for basic tasks.
Why FLEX 24V Brushless Cordless 6-1/2-Inch In-Line is better
Cutting Capacity
FLEX can cut 3x lumber in one pass.
Runtime
FLEX makes up to 430 cuts in 2x4 lumber.
Design
FLEX features an in-line design for better visibility.
Why Ryobi One P505 18V Lithium Ion Cordless 5 1/2" is better
Price
Ryobi is approximately 75% cheaper.
Weight
Ryobi is lighter and easier to handle.
Compatibility
Ryobi works with multiple 18V batteries.
Overall score
Specifications
| Spec | FLEX 24V Brushless Cordless 6-1/2-Inch In-Line | Ryobi One P505 18V Lithium Ion Cordless 5 1/2" |
|---|---|---|
| Brand | FLEX | RYOBI |
| Model | FX2131A-Z | P505 |
| Blade Size | 6-1/2" | 5-1/2" |
| Motor Type | Brushless | Brushed |
| Warranty | 5 years | 3 years |
Dimension comparison
Overview
When comparing the FLEX 24V Brushless Cordless 6-1/2-Inch In-Line Circular Saw to the Ryobi One P505 18V Lithium Ion Cordless Circular Saw, the FLEX model stands out with its advanced features and higher cutting capacity. The FLEX is priced at $177.66, while the Ryobi is significantly cheaper at $44.89, making it about 75% less expensive. However, the price difference corresponds with the performance capabilities and features of each saw.
Design and Build Quality
The FLEX boasts a unique in-line design that enhances balance and visibility during cuts, making it a first of its kind. This design allows for a clearer view on both sides of the blade, promoting greater accuracy. In contrast, the Ryobi features a transparent lower guard that enables maximum visibility while cutting. While both tools offer improved handling, the FLEX's design is tailored for precision, which can be crucial for intricate tasks.
Cutting Performance
The FLEX offers impressive cutting capacity, capable of cutting through 3x lumber in a single pass, with a depth of cut reaching 2-9/16 inches. This exceptional performance is supported by its powerful brushless motor, designed for efficiency. On the other hand, the Ryobi has a blade size of 5-1/2 inches and operates at a speed of 4,700 RPM. While it performs well for household tasks, it may struggle with larger cuts compared to the FLEX.
Battery and Runtime
With the FLEX, users can expect substantial runtime, capable of making up to 430 cuts in 2x4 lumber when paired with a 5.0Ah battery. However, both the FLEX and the Ryobi do not include batteries or chargers, which means additional costs for users looking to maximize their tools' performance. The Ryobi, compatible with various 18V batteries, provides flexibility but lacks the advanced battery management features found in the FLEX.
User Experience and Handling
The user experience with the FLEX is enhanced by its intelligent sensor-free brushless motor, which minimizes friction and maximizes power efficiency. This makes it easier for users to handle the saw during extended use. The Ryobi, with its GripZone overmolded handles, provides a reliable grip, reducing slippage during operation. The Ryobi's additional side handle improves control, especially for angled cuts, making it a good choice for DIYers who prioritize ease of handling.
Versatility
The FLEX's versatility is evident in its cross-compatibility with all FLEX 24V batteries, chargers, and tools, allowing users to build a comprehensive toolkit without restrictions. In contrast, the Ryobi is part of the ONE+ system, which is compatible with multiple 18V batteries, promoting interchangeability within its product line. This makes the Ryobi more appealing for those who already own other Ryobi tools, as it offers a seamless integration into an existing setup.
Price Point
At $177.66, the FLEX is a considerable investment, especially when compared to the Ryobi's price of $44.89. This means the FLEX is approximately 295% more expensive than the Ryobi. However, the higher price of the FLEX reflects its advanced features, cutting capacity, and enhanced runtime. For professionals or serious DIYers who require superior performance, the FLEX may justify the cost, while the Ryobi serves as a budget-friendly option for casual users.
Which should you buy?
Choosing between the FLEX 24V Brushless Cordless Circular Saw and the Ryobi One P505 ultimately depends on your needs. If you're a professional or an avid DIYer requiring robust cutting performance and advanced features, the FLEX is worth the investment for its superior capabilities and runtime. However, if you're looking for an affordable, reliable saw for basic household tasks, the Ryobi offers excellent value for its price, being about 75% cheaper than the FLEX.

