55mm Solderless Alligator Clips with Screw Terminals & Binding Posts – Red/Black, 40pcs

Large 55mm alligator clips with integrated screw terminals and binding posts for tool-free wire connection — no soldering required. The screw terminal clamps the wire directly to the clip body; the binding post accepts 4mm banana plugs for connection to bench power supplies, multimeters, and test equipment. The 55mm jaw length provides a secure grip on large terminals, bus bars, battery posts, and power electronics components. Supplied in matched red (positive) and black (negative) pairs for polarity identification.

Key Specifications

• Jaw Length: 55mm (large, for power electronics and battery terminals)
• Connection: Screw terminal (wire) + 4mm binding post (banana plug)
• Current Rating: 15–20A (depending on wire gauge and contact quality)
• Jaw Material: Copper alloy, nickel-plated
• Insulation: PVC sleeve
• Colors: Red and black (20 pairs)
• Quantity: 40 pieces (20 red + 20 black)

Screw Terminal vs Solder-Type Alligator Clips

• Solder-type: Wire is soldered to the clip body. Provides the lowest resistance connection. Permanent — wire cannot be changed without desoldering. Best for permanent test leads and production test fixtures.
• Screw terminal (this product): Wire is clamped by a screw. Tool-free wire change — loosen screw, insert wire, tighten. Slightly higher resistance than solder type due to the screw clamp interface. Best for lab bench use, temporary connections, and applications where the wire gauge or length needs to change frequently.
• Binding post (this product): Accepts 4mm banana plugs from bench power supplies and multimeters. Allows rapid connection to standard test equipment without stripping or clamping wires.

Frequently Asked Questions

What wire gauge can the screw terminal accept?

The screw terminal accepts wire from approximately 20AWG (0.5mm²) to 12AWG (4mm²). For stranded wire, use wire ferrules (end sleeves) to prevent individual strands from escaping the clamp area. Solid wire can be inserted directly. Do not exceed the screw terminal’s wire capacity — forcing oversized wire damages the terminal and reduces contact reliability.

What is the maximum current for these alligator clips?

The jaw-to-terminal contact is rated for 15–20A depending on contact pressure and jaw condition. For sustained high-current applications (battery charging, load testing), ensure the jaw is fully closed on a clean, oxide-free terminal surface. Corroded or partially-open jaws significantly increase contact resistance, causing heating at the clip. For currents above 20A, use dedicated high-current clamps (Kelvin clips or heavy-duty battery clamps).

Can I use these clips for automotive battery testing?

Yes. The 55mm jaw length accommodates standard automotive battery post sizes (top-post and side-post). Ensure the jaw makes full contact with the battery post — partial contact on a corroded post causes high resistance and inaccurate voltage readings. Clean the battery post with a wire brush before attaching the clip for accurate measurements.

Are the binding posts compatible with standard banana plugs?

Yes. The binding posts accept standard 4mm banana plugs used by Fluke, Keysight, Rigol, and other test equipment manufacturers. The binding post also accepts bare wire wrapped around the post shaft and secured by the knurled nut.

Typical Applications

• Lab bench testing: Connecting bench power supplies to circuits under test
• Battery testing: Voltage and capacity testing of automotive, lithium, and lead-acid batteries
• Power electronics: Temporary connections to capacitor banks, motor controllers, and inverters during development
• Educational: Physics and electronics lab experiments requiring temporary circuit connections
• Automotive diagnostics: Battery load testing, alternator output testing, voltage drop testing

Package Contents

40 pieces — 20× red alligator clips + 20× black alligator clips, each with screw terminal and 4mm binding post.