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RAM® Yoke Clamp Base with Ball and 1/4"-20 Threaded Hole
Part #: RAM-B-121BAU UPC: 793442903830

Product Information
Overview	The RAM-B-121BAU, yoke clamp mount with 1/4"-20 thread, will fit rails from 0.625" to 1.25" in diameter. The 1" rubber ball is set at a right angle to the plane of the mount, so when connected to a rail, the ball sits parallel to the rail.

Specifications
hardware included	Assembly Hardware
clamp range	.625" - 1.25"
ball size	B Size (1")
weight capacity	Standard Use: 2 lbs Heavy-Duty Use: 1 lb
materials	Marine-grade aluminum
packaging type	Poly Bag
Weight	0.36 lb

RAM® Yoke Clamp Base with Ball and 1/4"-20 Threaded Hole

Name: RAM® Yoke Clamp Base with Ball and 1/4"-20 Threaded Hole
Brand: RAM Mounts
SKU: RAM-B-121BAU
Price: 37.49 USD
Availability: InStock

Part#: RAM-B-121BAU

UPC: 793442903830

$37.49

Options

Overview

The RAM-B-121BAU, yoke clamp mount with 1/4"-20 thread, will fit rails from 0.625" to 1.25" in diameter. The 1" rubber ball is set at a right angle to the plane of the mount, so when connected to a rail, the ball sits parallel to the rail.

hardware included:

Assembly Hardware

clamp range:

.625" - 1.25"

ball size:

B Size (1")

weight capacity:

Standard Use: 2 lbs
Heavy-Duty Use: 1 lb

materials:

Marine-grade aluminum

packaging type:

Poly Bag

Weight:

0.36 lb

Return Policy:

All products purchased from RAM® can be returned within 30 days with no restocking fee (return shipping not provided). See full return policy here.

Print

Documents

Drawing File: Yoke Clamp Base

Aviation Catalog

Knowledge Base: Ball Sizes

QUESTIONS & ANSWERS

Have a Question?

Ask a Question

Can I use this to clamp to a flat surface?

You would need to replace the C-clamp with RAP-B-121-BBAU to mount on a flat surface.
Is the ball threaded so that it can be relocated to the other side in the threaded hole?

No, the threaded port of the RAM-B-121BAU is so you can add an additional ball that has a 1/4"-20 male threaded post, the ball included with that base mount attached to the yoke mount itself and is not intended to be removed.

RAM® Yoke Clamp Base with Ball and 1/4"-20 Threaded Hole

$37.49

Every RAM® mount is built around a rubber ball and socket system. The ball size sets how much weight the mount can carry. Match it to your device for smooth adjustment with a rock-solid hold.

RAM Mounts ball size specifications and typical uses
Size	Ball Diameter	Max Load*	Best For
A	0.56" (14.3 mm)	0.5 lb	Action cameras and other ultra-light devices
B — this product	1" (25.4 mm)	2 lbs	Phones, GPS units, and small tablets — the most common size
C	1.5" (38.1 mm)	4 lbs	Large tablets, fish finders, and rougher rides
D	2.25" (57.2 mm)	6 lbs	Rugged tablets, laptops, and heavy equipment
E	3.38" (85.9 mm)	15 lbs	Large displays and demanding aviation or industrial use

*Approximate capacity for a standard ball with a mid-length arm. Shorter arms and steel-reinforced posts increase real-world capacity.

Reading part numbers

The letter after RAM tells you the ball size: RAM-B-166 uses a 1" B ball, while RAM-D-201 uses a 2.25" D ball. C size parts are the exception and carry no letter, so RAM-201U is a C size arm.