Ball Ø 1.125 / 7/16-20-2BES438 7/16-20-2B / 7/16-20-2A Carbon Steel Ball Joint (Inch)
BALL JOINTS ES Product Overview
ES438 is a compact inch ball joint with a 7/16-20-2B female socket and a 7/16-20-2A male stud — a staked design with a rubber grommet shell. Overall length L = 0.750 in., ball housing diameter G = 1.125 in., flange thickness F = 0.875 in., body width P = 1.000 in., overall height N = 1.938 in., body reach C = 2.375 in.
The ES series uses a carbon steel 1045 housing, a carbon steel 1045 ball stud, and a rubber grommet shell. Silver or yellow zinc plating provides corrosion resistance for OEM and replacement-duty use. Suitable for compact control-link systems, fabricated linkage assemblies, throttle and brake linkages, and OEM replacement applications where a staked ball-joint socket with female-to-male thread connection is required.
Left-hand thread version available by adding ‘LH’ suffix. Yellow zinc plating available on request. Metric equivalent is the CS series.
BALL JOINTS ES Series — Full Size Range
All available sizes in the BALL JOINTS ES series. Can’t find your size? Contact us for custom dimensions.
| PART NO. | M | M1 | L | G | F | P | N | C |
|---|---|---|---|---|---|---|---|---|
| ES187 | 10-32-2B | 10-32-2A | 0.375 | 0.438 | 0.438 | 0.438 | 0.875 | 1.063 |
| ES250 | 1/4-28-2B | 1/4-28-2A | 0.438 | 0.563 | 0.469 | 0.500 | 0.969 | 1.219 |
| ES312 | 5/16-24-2B | 5/16-24-2A | 0.500 | 0.688 | 0.531 | 0.563 | 1.125 | 1.406 |
| ES375 | 3/8-24-2B | 3/8-24-2A | 0.625 | 0.875 | 0.688 | 0.750 | 1.375 | 1.688 |
| ES438 | 7/16-20-2B | 7/16-20-2A | 0.750 | 1.125 | 0.875 | 1.000 | 1.938 | 2.375 |
| ES500 | 1/2-20-2B | 1/2-20-2A | 0.750 | 1.125 | 0.875 | 1.000 | 1.938 | 2.375 |
| ES625 | 5/8-18-2B | 5/8-18-2A | 0.875 | 1.125 | 1.000 | 1.000 | 2.063 | 2.578 |
Every Unit Inspected Before Shipment
Raw Material Inspection
Material certifications verified. Composition confirmed by spectrometer before machining begins.
Thread Gauge Inspection
100% go/no-go gauge check on all threaded sections. Zero tolerance on dimensional non-conformance.
Load Capacity Test
Static and dynamic load tests run on representative samples from each production batch.
Dimensional Measurement
CMM verification of critical dimensions — ball diameter, bore, thread pitch, and body length.
Surface Inspection
Visual and tactile inspection for burrs, scratches, surface cracks, and plating defects.
Articulation Test
Misalignment angle and torque measured to confirm liner performance meets specification.
Heat Treatment Verify
Hardness tests confirm proper heat treatment on chromoly steel bodies and bearing balls.
Batch Documentation
Full traceability from raw material heat number to finished part. COC and inspection reports available.
Where BALL JOINTS ES Small Ball Joints Are Used
More from the BALL JOINTS ES Series
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BALL JOINTS ES Frequently Asked Questions
What is the ES series ball joint used for?
The ES series is used in compact inch-thread control links, steering-related mechanisms, throttle systems, and other articulated joints that need staked construction with rubber-grommet protection.
What materials are used in the ES series?
The standard ES series uses a carbon steel 1045 housing, a carbon steel 1045 ball stud, a rubber shell, and a silver or yellow zinc-plated surface finish.
What is the benefit of the rubber shell on ES ball joints?
The rubber shell helps protect the joint area from contamination while supporting a compact staked design for linkage applications that need cleaner articulated movement.
Are left-hand thread versions available?
Yes. Left-hand versions are available by adding the LH designation to the applicable ES part number when that thread direction is required.
How do I choose the correct ES size?
Match the required d1 and d2 thread sizes, ball diameter, and key body dimensions in the ES size chart. If fit-up constraints matter, send your target dimensions for selection support.
Can ES ball joints be supplied in different zinc-plated finishes?
Yes. The ES series is available in silver or yellow zinc-plated finish. If finish consistency matters for your program or replacement set, confirm the finish requirement in your RFQ.