Bike Locks: Hardened 420 vs Boron Steel Chains

 

Why hardened 420 shackles resist bolt cutters?
Heat-treated to 55 HRC, 420 shackles require >10,000N force to shear – defeating standard 36" cutters. Case-hardened surfaces (0.5mm depth) prevent hacksaw penetration. Double-ball bearings in locks prevent picking. Always secure both wheels + frame.

 

Boron steel chain advantages?
Boron-infused links (14mm thickness) absorb angle grinder heat, buying 5+ minutes versus standard steel. Interlocking design resists leverage attacks. Wrap in nylon sleeves to prevent frame scratches. Minimum 90cm length for proper securing.

 

Preventing lock freezing?
Spray dry Teflon lubricant into keyholes before winter. Cover locks with silicone caps when parked overnight. Never use oil – attracts dirt causing jams. Store indoors during extreme cold snaps.

 

Theft-deterrent positioning?
Elevate locks >1m off ground – harder to attack with tools. Secure to immovable objects (e.g., steel posts >100mm diameter). Avoid leaving slack – tension reduces cutting leverage.

 

Maintenance schedule?
Lubricate mechanisms quarterly with graphite powder. Inspect shackles for saw marks monthly. Replace after any visible attack attempts or key rotation stiffness.