SMC Extra Large Heavy Duty Steel Screw Locking Carabiner

This SMC large steel carabiner is an extra large heavy duty carabiner for connections that see abuse: rigging, anchors and setups where several slings or a thick rope have to fit. Heat-treated steel resists wear from rope and hardware far better than aluminum.

Why steel

Steel carabiners weigh more than aluminum, but they shrug off the grooving that rigging rope and steel hardware cause. That makes them a smart choice for rigging connections, anchors and gear that sits in the truck bed between jobs.

The large size gives room for bigger rope, several slings or a block and a sling together.

Heat treatment hardens the steel so it resists wear, which is why steel carabiners last longer on rigging lines that carry grit and sap. The trade-off is weight, so most climbers keep steel off the saddle and in the rigging bag.

Use and inspection

Read the ratings on the spine and keep loads within them, remembering that rigging forces can far exceed the weight of a piece of wood. Lock the screw gate and check it every time. Retire it if it shows cracks, bending or deep wear. For life-support use, confirm the carabiner is rated for it and follow the applicable standard. See more in screw gate carabiners.

When stacking several connections in the basket, keep the loads near the spine and avoid three-way loading unless the manufacturer allows it. Screw the gate closed, then squeeze the gate to confirm it is locked, and recheck after rope has been running past it.