Carabiners

Direct Answer

Climbing carabiners and connectors are certified under European standard EN 12275 and UIAA 121. Major certifications specify minimum breaking strength across three loading axes: Major Axis Closed (standard Type B ≥ 20 kN / Type H HMS ≥ 20 kN / Type K Via Ferrata ≥ 25 kN), Minor (Cross) Axis (≥ 7 kN), and Open Gate (≥ 7 kN for Type B/H, ≥ 8 kN for Type K). Locking mechanisms include Screw-Lock, Auto-Lock (twist-lock 2-stage), and Triple-Lock (lift-twist-open 3-stage).

Source: EN 12275 (Mountaineering equipment–Connectors) / UIAA 121 / EN 362 (Industrial connectors) · Last reviewed Aug 28, 2026

Specs

Type B (Basic) Major Axis Closed	≥ 20.0 kN (minimum 4,496 lbf breaking strength)
Type B Minor / Cross-Axis Strength	≥ 7.0 kN (minimum 1,574 lbf)
Type B Open Gate Strength	≥ 7.0 kN (strength when gate is forced open)
Type H (HMS / Pear Shape) Major Axis	≥ 20.0 kN (designed for Munter hitch belaying)
Type K (Klettersteig / Via Ferrata)	≥ 25.0 kN (reinforced for heavy steel cable shear loads)
Type D (Directional / Quickdraw)	≥ 20.0 kN (integrated webbing retention)
Gate Opening Clearance (Type B)	≥ 15.0 mm minimum gate clearance
Gate Opening Clearance (Type H)	≥ 20.0 mm minimum gate clearance
Locking Mechanism Tiers	Screw-Lock, Twist-Lock (2-action), Triple-Lock (3-action) Safety Mechanisms
Primary Material	Hot-Forged 7075-T6 Aircraft Aluminum Alloy or Heat-Treated Steel Standard

Tri-Axial Strength Markings & The Danger of Cross-Loading

Laser-Etched kN Ratings: Every certified carabiner is permanently engraved on its spine with three ratings: Major Axis Closed (e.g. ↔ 24 kN), Minor Axis Cross-Loaded (e.g. ↕ 8 kN), and Gate Open (e.g. ⎕ 8 kN). 1 kN equals approximately 224.8 pounds-force (100 kg under Earth gravity = ~1 kN).
Cross-Loading Hazard: When a carabiner shifts sideways and is loaded across its narrow minor axis against the gate barrel, its breaking strength plummets from 24 kN to just 7–8 kN, well below the peak shock forces generated in severe leader falls.