RAM Mounts 1/4"-20 Female Thread Ball Adapter with Hex Post, B Size 1" Ball (RAM-B-337U)
Quick take
The RAM-B-337U is a RAM ball-and-socket adapter that gives you a B size 1" ball connection for devices that bolt to a 1/4-20 threaded hole. It is especially useful for motorcycles and boats where you want flexible positioning and a rugged, marine-grade aluminum build. The main buying caveat is fitment: you need (or must provide) a compatible 1/4-20 threaded mounting setup, since this adapter does not include a mounting bolt for every use case.
Pros and cons
Pros
- 1/4-20 female threaded hex hole connects to a wide range of custom threaded mounting points.
- B size 1" rubber ball lets you join the RAM ball-and-socket system for near-infinite adjustability.
- Marine-grade, powder-coated aluminum is designed for demanding environments.
- Standard-use and heavy-duty weight capacity ratings provide clarity for typical gear.
Cons
- Works only if your setup can use a 1/4-20 thread (you may need to source matching hardware).
- Some buyers expect included mounting hardware like a bolt, but this version is designed as an adapter without a bolt.
- Threading can be less forgiving if you are working aluminum threads into softer materials (relevant for DIY builds).
What buyers think
Buyer-review evidence points to dependable fitment when using the correct 1/4-20 threaded interface. Multiple reviews describe straightforward installation into existing motorcycle or vehicle threaded points, including cases where custom threaded rods were used, with the RAM ball threading fitting as expected. Review themes also emphasize the usefulness of having the RAM ball head for adjustable positioning in real-world mounts (for cameras, brackets, and device holders). Finally, durability and warranty support come up, with buyers noting that RAM’s lifetime warranty process is easy when a failure occurs. Overall, buyer-review evidence is limited in technical depth, but it consistently supports the adapter’s practical installability and adjustability for DIY and vehicle mounting projects.
What this adapter does (and why it matters)
This adapter’s job is to give your existing threaded mounting point a RAM ball connection. The RAM-B-337U pairs a 1/4-20 female threaded hex hole with a B size 1" rubber ball. Once you have that ball, you can connect it to compatible RAM double socket arms and other RAM ball-and-socket components, which is what unlocks the flexible “set it where you want it” positioning that many vehicle mounts are known for.
Key specs that affect compatibility
- Thread interface: 1/4-20 female threaded hex hole (female).
- Ball size: B size 1" ball, intended for the RAM ball-and-socket system using B size components.
- Material and finish: marine-grade aluminum with a powder-coated finish, plus a rubber ball.
- Weight capacity: 2 lb for standard use, 1 lb for heavy-duty use (use this as a guide for what you mount).
- Use profile: commonly used as a boat mount or vehicle mount adapter, including custom builds for cameras and accessories.
Installation reality: what to plan for
This adapter is designed as a “threaded hole to RAM ball” connector. That usually means you will either have an existing 1/4-20 threaded location, or you will source matching 1/4-20 hardware (such as threaded rods of the right length) to adapt your vehicle part to the RAM ball. If your project depends on a specific mounting bolt being included, double-check whether you need to supply your own threaded rod or bolt hardware.
Pros and cons for different buyers
Best for
- Motorcycle and boat accessory builders: anyone creating a camera, bracket, or device holder that needs adjustable positioning.
- RAM ball-and-socket system owners: you likely want more connection points using the B size 1" ball standard.
- Rugged-environment mounting: the marine-grade aluminum and powder-coated finish are tailored for tougher use settings.
Who should avoid (or think twice)
- If you do not have (or cannot adapt to) a 1/4-20 threaded mounting point.
- If you need an adapter with a specific included mounting bolt for your exact vehicle part. This version is oriented around the adapter interface, not a one-size-fits-all bolt.
- DIY users concerned about thread damage risk: metal threads can be sensitive in certain material combinations, so it helps to plan careful engagement and hardware compatibility for your build.
Is it worth it?
It is worth considering when you already plan to use RAM ball-and-socket components and you want a durable, adjustable connection from a 1/4-20 threaded interface. Buyers’ experiences most consistently line up with the idea that the threading and fit are practical for vehicle projects, and that the ball head makes positioning easier once installed. If your priority is a direct, bolt-on replacement with no sourcing of matching threaded hardware, you may want to look for a version that matches your vehicle’s mounting hardware more directly.
Price and availability
The current selling price can change, so it is a good idea to verify the latest cost before ordering. You can check the most up-to-date price and listing details here: Buy on Amazon.
FAQ
What does the RAM-B-337U connect to?
It connects to the RAM ball-and-socket system using a B size 1" rubber ball. Once you have that ball, you pair it with compatible RAM double socket arms and related ball-and-socket components.
What size thread is required for mounting?
The adapter uses a 1/4-20 female threaded hex hole. Your mounting setup needs to provide a matching 1/4-20 male threaded connection (or you need to supply appropriate 1/4-20 hardware).
Does it come with a mounting bolt?
This version is positioned as a ball adapter with the threaded hole, not as a complete bolt kit for every application. If your project needs a specific bolt or threaded length, you may need to source it separately.
How much weight can it support?
It lists 2 lb for standard use and 1 lb for heavy-duty use. Choose your mounting plan accordingly, especially for vibration and movement on vehicles.
What is the material and finish?
It is made from marine-grade aluminum with a powder-coated finish, paired with a rubber ball.
Is it a good option for motorcycles or boats?
It is commonly used for vehicle and marine accessory mounting because it is built for demanding environments and provides adjustable ball-and-socket positioning. If your mounting point is compatible with a 1/4-20 threaded interface, it is a practical choice.
Specifications
| Product Title | RAM Mounts 1/4"-20 Female Thread Ball Adapter with Hex Post, B Size 1" Ball, Camera & Accessory Mount Adapter RAM-B-337U |
|---|---|
| Category | Electronics > GPS, Finders & Accessories > GPS System Accessories > Vehicle Mounts |
| Brand | RAM MOUNTS |
| Manufacturer | RAM MOUNTS |
| Model Number | RAM-B-337U |
| Color | Black |
| Material | Marine Grade Aluminum, Rubber |
| Item Weight | 27.22 g |
| Brand Name | RAM MOUNTS |
| UPC | 793442904578 671142572429 066511788578 |
| Global Trade Identification Number | 00066511788578 |
| Manufacturer Part Number | RAM-B-337U |
| Manufacturer Warranty Description | Manufacturer Warranty |
| Included Components | Auto part, Automotive Accessories, Replacement and Performance parts |
| Item Type Name | 1/4-Inch-20 Female Threaded Hex Hole With 1-Inch Ball |
| Item Dimensions | 1.5 x 1 x 1 inches |
| Material Type | Marine Grade Aluminum, Rubber |
| Mounting Type | Boat Mount |
| Finish Types | Powder Coated |
| Item dimensions L x W x H | 1.5 x 1 x 1 inches |
Available variants
Size
- 1/4"-20 Threaded Hole
Color
- Black
Recommended next
Garmin Varia Radar Seat Rail Mount
The Garmin Varia Radar Seat Rail Mount is an optional kit that lets you attach a compatible Varia rearview radar under your saddle on standard 7 mm round alloy seat rails. It tidies up the look and can feel more secure than lower-cost rail mounts, but you will want to double-check rail type and whether the mount clears your saddle bag. View latest price on Amazon.
FANAUE DA-150PRO double socket swivel arm (5.9-inch) for RAM-style mounts
The FANAUE DA-150PRO is a compact double-socket arm designed to extend and re-angle RAM Mounts B-size (1-inch ball) setups. Based on buyer feedback, it stands out for tight ball locking, solid build quality, and flexible positioning for devices like cameras and action cams on handlebars. The main caveat is compatibility, it only makes sense if your mount system uses the 1-inch B-size ball standard.
VK-162 USB GPS Dongle
The Stratux VK-162 is a remote-mount USB GPS dongle built for plug-and-play style setups, including Stratux and Raspberry Pi projects. It uses a u-blox 7 chipset (WAAS capable) and comes with a 7 ft cable and magnetic base, plus an IPX6 rating for water and dust resistance.
BRCOVAN Aluminum Alloy Anti-Theft Double Socket Arm
The BRCOVAN Aluminum Alloy Anti-Theft Double Socket Arm is a compact, 6061-T6 aluminum double-socket extension made for secure 1-inch ball mount setups. It focuses on durability and theft resistance with a special anti-theft screw and included adjustment wrench, but it may be less convenient if you frequently change mount angles.