Ball Ø 0.687 / 5/16-24-2BQD315 5/16-24-2B / 5/16-24-2A Carbon Steel Ball Joint (Inch)
BALL JOINTS QD Product Overview
QD315 is an inch quick-release ball joint with a 5/16-24-2B female socket and a 5/16-24-2A male stud. A stainless steel internal spring enables fast disconnect and reconnect without tools. Pin diameter A = 0.156 in., spring clearance C = 0.094 in., housing flange F = 0.531 in., ball housing G = 0.687 in., journal J = 0.437 in., body length L = 0.625 in., overall length M = 1.453 in., height N = 1.125 in., body width P = 0.605 in.
The QD series uses a carbon steel 1045 housing, a carbon steel 1045 ball stud, a carbon steel 1020 shell, and a stainless steel spring. Silver or yellow zinc plating is standard. The quick-disconnect feature suits applications where linkage arms are frequently detached for adjustment, maintenance, or seasonal service — including throttle linkages, agricultural implement controls, and OEM assemblies with regular field service.
Aluminum version available with ‘A’ prefix (e.g., AQD315). Left-hand thread version available by adding ‘LH’ suffix. Yellow zinc plating available on request. Internal-spring variant is the QI series.
BALL JOINTS QD Series — Full Size Range
All available sizes in the BALL JOINTS QD series. Can’t find your size? Contact us for custom dimensions.
| PART NO. | D1 | D2 | A | C | F | G | J | L | M | N | P |
|---|---|---|---|---|---|---|---|---|---|---|---|
| QD187 | 10-32-2B | 10-32-2A | 0.125 | 0.063 | 0.438 | 0.438 | 0.313 | 0.438 | 1.094 | 0.906 | 0.438 |
| QD250 | 1/4-28-2B | 1/4-28-2A | 0.125 | 0.063 | 0.469 | 0.562 | 0.375 | 0.562 | 1.250 | 0.969 | 0.531 |
| QD315 | 5/16-24-2B | 5/16-24-2A | 0.156 | 0.094 | 0.531 | 0.687 | 0.437 | 0.625 | 1.453 | 1.125 | 0.605 |
| QD375 | 3/8-24-2B | 3/8-24-2A | 0.187 | 0.094 | 0.687 | 0.875 | 0.500 | 0.750 | 1.750 | 1.375 | 0.812 |
| QD500 | 1/2-20-2B | 1/2-20-2A | 0.250 | 0.094 | 0.875 | 1.125 | 0.625 | 1.000 | 2.530 | 2.030 | 1.000 |
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 QD Small Ball Joints Are Used
More from the BALL JOINTS QD Series
Request a Quote for the BALL JOINTS QD Series
Share your part number, required quantity, and any special material or packaging requirements. We respond within 24 hours.
Request a Quote
Please submit the form or email [email protected]
BALL JOINTS QD Frequently Asked Questions
What is the QD series ball joint used for?
The QD series is used in compact quick-release linkage points where inch-thread articulation is needed together with easier service access and repeatable disconnect capability.
What materials are used in the QD series?
The standard QD series uses a carbon steel 1045 housing, carbon steel 1045 ball stud, carbon steel 1020 shell, stainless steel spring, and a silver or yellow zinc-plated surface finish.
What is the benefit of the quick-release design?
The quick-release layout allows faster disconnect and reconnect during maintenance, adjustment, or replacement work, which helps reduce service time in suitable linkage designs.
Is an aluminum version available?
Yes. Aluminum-material versions are available by adding the A prefix to the QD part number, subject to production availability and specification confirmation.
Are left-hand thread versions available?
Yes. Left-hand versions are available by adding the LH designation to the applicable QD part number when that thread direction is required.
How do I choose the correct QD size?
Match the required d1 and d2 thread sizes, ball diameter, release geometry, and body dimensions in the QD size chart. If service access or space limits are critical, send your dimensional requirements for support.