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The Lincoln Electric K910-2 is a heavy-duty spring ground clamp, also sold as the GC-500, rated at 500 amps at a 60 percent duty cycle with jaws that open about 2-1/2 inches. It suits MIG, TIG and stick welders who want a reliable work clamp for gripping edges, bars and fixtures. If you mostly weld on flat sheet and need a one-handed clamp, consider a magnetic ground instead.
K910-2 Ground Clamp at a Glance
| Item | Detail |
|---|---|
| Model | Lincoln Electric K910-2 (GC-500 work clamp) |
| Rating | 500 A at 60% duty cycle, per Lincoln and retailer listings |
| Jaw opening | About 2-1/2 inches (63 mm) |
| Construction | Copper-plated jaw with braided copper shunt, per the listing |
| Weight | About 14.9 oz per the listing |
| Cable connection | Verify the lug type and cable size range on the current listing |
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What It Is and Who It Suits
A ground (work) clamp completes the welding circuit. A poor one causes unstable arcs, heat at the clamp, and wasted current. A spring clamp with a copper contact surface and a braided shunt that carries current around the spring is a standard way to build a durable, low-resistance connection.
The K910-2 suits shop and field welders using 200 to 400 amp machines who need a robust replacement for a worn clamp. It is probably more clamp than you need for a small 120 V machine, but it works if the cable connection fits.
How to Check the K910-2 Fits Your Setup
- Cable size: match the clamp to your ground cable gauge. Confirm the accepted range before ordering.
- Connection: check how the cable attaches to the clamp, and whether you can crimp or bolt it. Use the correct lug and insulation.
- Ratings: a 500 A rating is the clamp’s capability. The cable and machine duty cycle still limit your use.
- Workpiece shapes: 2-1/2 inch jaw opening covers most plate edges, bars and tube. Wider stock needs a different approach.
- Spring tension: a loose or weak spring needs replacing, as does a clamp with pitted jaws.
Pros and Limitations
Pros
- 500 A rating suits heavy machines
- Spring operation without tools to tighten the grip
- Braided shunt for current flow around the spring
- Lincoln brand and a standard part number
Limitations
- Jaw opening limited to about 2-1/2 inches
- Cable fit and lug style need checking
- Needs clean contact surface to perform
- Not a magnet clamp for quick placement on flat sheet
Using and Maintaining a Ground Clamp
- Clamp as close to the weld as practical, on clean bare metal.
- Grind off paint, rust and mill scale at the clamp spot.
- Check that the cable-to-clamp connection is tight and the insulation is intact.
- Replace clamps that show burn marks, loose springs or damaged cable ends.
- Never ground through bearings, hydraulic parts or electronics; connect directly to the workpiece.
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Alternatives and Related Guides
- Compare a lighter clamp: Qwork 300 amp welding ground clamp review.
- Prefer a magnet? Read the magnetic welding ground clamp review.
- Building a lead? See the heavy-duty welding cable lead reel review.
- Need an electrode holder? Compare the 500 amp electrode holder review.
Frequently Asked Questions
What is the Lincoln K910-2 ground clamp rated for?
Lincoln lists the K910-2, also sold as the GC-500 work clamp, at 500 amps with a 60 percent duty cycle and jaws that open about 2-1/2 inches. Those are the clamp’s ratings, so your welding cable and machine still set the real limit.
Will it fit my welding cable?
The clamp has to accept the cable size and connection style of your ground lead, commonly a bolted or set-screw lug on heavier cables. Check the cable gauge range in the current listing or Lincoln documentation before buying, and follow the instructions to make a tight, clean connection.
Why does my ground clamp get hot?
Heat usually means poor contact, a loose cable connection, a clamp that is undersized for the current, or dirty jaws on rusty or painted metal. Clean the contact spot to bare metal, tighten the cable connection and use a clamp rated for your amperage and duty cycle.
Is a spring ground clamp better than a magnetic one?
Spring clamps like this grip tubing, bars, edges and tables firmly, and they handle high current well. Magnetic clamps are fast on flat steel but can lose grip, may heat up at high amps and are not for every job. Many shops keep both types.
Verdict
The K910-2 is a solid, no-frills ground clamp for heavy stick, MIG and TIG work. Confirm that your cable and lug fit, then keep the contact surface clean for best results. Check the current listing for details.
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