D-Ring Quick Release Ball Lock Pin | 17-4PH Stainless Steel | Single & Double Acting | JDF
The D-Ring Quick Release Ball Lock Pin is a positive-locking, quick-release alignment pin with a precision-ground shank and a D-ring handle. The D-ring design is specifically suited for applications with limited space around the pin, where a T-handle or L-handle would be difficult to operate. The spring-loaded balls engage close-fitting holes to lock the pin securely in place, and will not release until the button on the handle is depressed. Available in single-acting and double-acting configurations, in 17-4PH stainless steel or 300 series stainless steel.
How to select the right D-Ring Ball Lock Pin:
Determine the pin diameter: Match the pin diameter to the mounting hole. Recommended hole tolerance is H11.
Measure the grip length: The grip length is the distance from the bottom of the handle to the ball center. It must match the total thickness of the plates being joined. Standard grip lengths range from 10mm to 100mm.
Calculate the load: Determine the shear load the pin will experience. Apply a safety factor of 2 for static loading, or 3 for dynamic/impact loading.
Select the material: Choose 17-4PH stainless steel (HRC40 min) for higher shear strength applications, or 300 series stainless steel for general corrosion resistance.
Choose single-acting or double-acting: Single-acting releases with a button press; double-acting requires button press + rotation for added security against accidental release.
Example: For a 500 kg static load in double shear, with a safety factor of 2, the required shear strength is 1000 kg (approx. 2200 lbf). A 3/8" diameter 17-4PH pin (double shear strength approx. 36,900 lbf) is more than sufficient.
Installation and Operation:
Insert the pin into the mounting hole with the button depressed. The spring-loaded balls will retract, allowing the pin to slide through.
Release the button. The balls will spring out and engage the groove or hole on the far side, locking the pin in place.
To remove, press the button (single-acting) or press and rotate (double-acting). The balls retract and the pin can be pulled out.
The D-ring handle allows operation in tight spaces where a T-handle would be obstructed. The ring can also be used with a lanyard to prevent loss.
Technical Specifications Table
Model Pin Diameter (mm) Grip Length (mm) Shank Material Ball Material Action Double Shear Strength (kN) JDF-DR-6-30 6 30 17-4PH 440C Single Acting Approx. 52 JDF-DR-8-40 8 40 17-4PH 440C Single Acting Approx. 92 JDF-DR-10-50 10 50 17-4PH 440C Single Acting Approx. 144 JDF-DR-12-60 12 60 17-4PH 440C Double Acting Approx. 207 JDF-DR-16-80 16 80 17-4PH 440C Double Acting Approx. 368 Typical Applications
The D-Ring Quick Release Ball Lock Pin is widely used in the following applications:
Aerospace & Aviation: Quick release of aircraft access panels, with D-ring handle for operation in tight spaces
Fixtures & Positioning: Quick locating and locking of workpieces on fixtures, with positive locking to prevent accidental release
Mold & Die Changing: Fast locking and release of molds during changeover, improving efficiency
Industrial Equipment Maintenance: Quick fastening of frequently removed panels, covers, and guards
Sports & Outdoor Equipment: Quick connection applications such as bicycles and fitness equipment
FAQ
Q1: What is the difference between a D-ring handle and other handle types?
A: The D-ring handle is designed for applications with limited space around the pin. The ring allows fingers to pass through for operation where a T-handle or L-handle would be obstructed. The D-ring can also be used with a lanyard to prevent loss.
Q2: What is the difference between single-acting and double-acting ball lock pins?
A: Single-acting pins release with a simple button press, offering quick and convenient operation. Double-acting pins require both button press and rotation to release, providing higher security against accidental release, suitable for applications with vibration or where accidental operation must be prevented.
Q3: How do I measure the grip length?
A: The grip length is the distance from the bottom of the handle to the ball center. Measure the total thickness of the plates being joined and select a pin with a matching grip length. A grip length that is too short results in unreliable locking, while one that is too long affects operation.
Q4: What is the difference between 17-4PH stainless steel and 300 series stainless steel?
A: 17-4PH is a precipitation-hardening stainless steel that achieves HRC40+ hardness after heat treatment, offering higher shear strength and excellent corrosion resistance for high-load applications. 300 series stainless steel is austenitic, with good corrosion resistance but lower strength, suitable for general load and corrosive environments.
Q5: How do I calculate the load capacity of a ball lock pin?
A: Ball lock pin load capacity is measured by double shear strength and pull-out strength. Double shear strength is the fracture load of the pin under two shear planes. Pull-out strength is the force required to dislodge the ball from the hole. Select with a safety factor of 2 for static loads, or 3 for dynamic/impact loads.
