What is the difference between wiper blade size A and B?
In most cases, there is no universal standard for what “A” or “B” means on wiper blades; these letters are brand- and model-specific codes that often indicate mounting adapters, blade geometry, or subtle length differences within a product line. The practical difference is what fits your vehicle, not a universal measurement.
To understand precisely what A and B mean on a given product, you must check the specific blade’s specifications and your vehicle's requirements. The letters rarely map to a universal size; instead, they indicate compatibility within that brand’s lineup. Always verify with the exact part number and fitment guide before buying.
What A and B typically signify
A) Mounting adapters or connector types
Some brands designate A for one connector type and B for another. This matters because the wiper arm attaches via different fittings (such as J-hook, pin, or bayonet). If the connector doesn’t match, the blade won’t attach securely or function properly.
B) Blade length variations within the same line
In some product lines, A and B correspond to different blade lengths marketed together as compatible options. Always verify the length on the packaging to ensure it matches your vehicle’s requirement and the correct side of the windshield.
C) Blade geometry differences (beam vs conventional/frame)
Some manufacturers use A and B to distinguish between blade geometries. Beam blades (unibody designs) and traditional frame blades have different pressure profiles and contact behavior; choose the one that aligns with your windshield shape and climate conditions.
D) Position-specific coding (driver side vs passenger side)
In rarer cases, letters indicate side-specific variants in a product line. If so, ensure you’re selecting the correct A or B for each windshield position. Most brands do not use this scheme, but it can appear in certain lines.
Because brand definitions vary, always check the product’s compatibility guide and the vehicle’s requirements to avoid a mismatch.
How to confirm which A or B you need for your vehicle
To avoid buying the wrong blade, follow these steps to verify compatibility:
- Check the vehicle’s owner manual or the blade replacement section for the recommended part or length.
- Use the retailer’s fitment tool by entering year, make, model, and trim; compare the available A and B options shown.
- Compare the blade part numbers on the packaging with those listed for your vehicle; some brands list multiple codes for the same length.
- Inspect the current blade’s connector type (J-hook, pin, bayonet, or side-pin) and ensure the new blade uses the same connector (A vs B can indicate a different connector).
- Measure the blade length if needed and verify it against the product listing; ensure both driver and passenger sides are correct if lengths differ.
In case of doubt, contact the retailer’s support or bring the old blade to the store for a hands-on comparison. Getting the wrong blade can result in poor contact or streaking on the windshield.
Practical tips for finding the right wiper blades
Always cross-check the exact part number and fitment guide rather than relying solely on the letter designation. If you’re switching brands, confirm the connector type and length anew, since A and B are not standardized across manufacturers.
Summary
The difference between wiper blade size A and size B is not governed by a universal standard. The letters are brand-specific codes that typically reflect mounting adapters, blade length variants, or blade geometry within a given product line. To ensure proper fit and performance, consult the vehicle’s requirements and the exact product specifications from the manufacturer or retailer.
What does the A stand for on Bosch wiper blades?
BOSCH ICON Wiper Blades - Singles
A: "A" is for the driver side and for some vehicles the passenger side. "B" is for vehicles that require a different wiper on the passenger side. "OE" means Original Equipment Fitment, and has to do with the type of arm connectors the blade has. The OE blades are not side specific.
What does the A mean on wiper blades?
The 'A' on a wiper blade indicates it is for the driver's side, while a 'B' is for the passenger's side in vehicles that require a different curvature for that side. The 'A' and 'B' designations refer to the spring force and blade curvature, with 'B' blades having a greater curve to hug the more curved windshield on the passenger side, ensuring better contact and clarity.
'A' vs. 'B' wiper blades
- 'A': This blade is designed for the driver's side of the vehicle. In some cases, an 'A' blade may also be compatible with the passenger side.
- 'B': This blade is specifically for the passenger side, featuring a greater curvature to maintain contact with the windshield, which is often more curved on that side.
What to do if you are unsure
- Check your vehicle's specifications: The best approach is to use the vehicle manufacturer's information or an online parts finder to determine the correct part number for each side of your car.
- Start with 'A': If you are unsure, you can try using the 'A' blade on both sides. If you notice the edges of the blade are not clearing the windshield properly, you may need to switch the passenger side to a 'B' blade.
What is the difference between 19a and 19b wiper blades?
A: A is for driver's side, B is for passenger's. It has to do with the curve of the wiper's blade spring. The spring has a tighter hook to it on the outside end, which helps it maintain contact at the edges of aggressively curved windshields.
What is the difference between A and B wiper blades?
Driver side always has an “A” part number. Passenger side can have an “A” or “B” part number depending on the vehicle. Blades with a “B” part number have a greater curvature specifically designed to wrap around the passenger side window for greater visibility and clarity.
