Lock bumping has been called a "universal key" by the media, capable of opening virtually any pin tumbler lock in seconds. While the threat is real, the panic is often overblown. Understanding how bumping works and what defenses exist helps you make informed security decisions.
What is Lock Bumping?
Lock bumping is a technique that uses a specially cut "bump key" to open pin tumbler locks. Here's how it works:
- A bump key is cut so all its valleys are at the maximum depth
- The key is inserted into the lock, then pulled back one notch
- While applying slight rotational pressure, the key is "bumped" with a mallet or screwdriver handle
- The impact momentarily bounces the pins to the shear line, allowing the lock to turn
When done correctly, bumping can open a standard pin tumbler lock in under 10 seconds, with minimal evidence of entry.
How Real is the Threat?
Let's put bumping in perspective:
- Most burglars don't use it - Kicking in a door is faster and requires no skill
- It requires practice - Despite what YouTube suggests, consistent bumping takes skill
- Better tools exist - Professional criminals use more reliable methods
- Bump keys leave evidence - Forensic analysis can detect bumping
That said, bump-resistant locks provide peace of mind and protection against this technique.
Important Reality Check
The vast majority of break-ins (about 30%) occur through unlocked doors and windows. Bumping is a concern, but basic security practices matter more.
Locks Vulnerable to Bumping
Standard pin tumbler locks without security features are vulnerable. This includes:
- Most builder-grade deadbolts (Defiant, Generic brands)
- Standard Kwikset and Schlage locks without security pins
- Many older locks from any manufacturer
- Padlocks with standard pin tumblers
Bump-Resistant Lock Technologies
Security Pins
Spool, serrated, and mushroom pins are designed to bind at the shear line when bumped, requiring additional manipulation to open. These are the most common defense.
Side Pins/Sidebar Locks
Locks like Medeco and Mul-T-Lock use pins that must also rotate to a specific angle, not just reach the correct height. Bumping can't replicate this rotation.
Electronic Locks
Smart locks and electronic deadbolts have no traditional key mechanism to bump. They're immune to this technique (though have other considerations).
Magnetic Locks
Locks using magnets instead of or in addition to pins cannot be bumped.
Best Protection
Locks rated ANSI/BHMA Grade 1 with UL 437 certification for high security provide the best bump resistance. Look for brands like Schlage Primus, Medeco, ASSA, or Mul-T-Lock.
Recommended Bump-Resistant Locks
Budget-Friendly Options
- Schlage B60N - Features anti-pick security pins, good bump resistance
- Kwikset SmartKey - Side-locking bar makes bumping very difficult
Mid-Range Security
- Schlage B660P - ANSI Grade 1, security pins, reinforced strike
- Medeco Maxum - Rotating pins that must align in addition to height
High-Security Options
- Medeco M3 - UL 437 rated, virtually bump-proof
- Mul-T-Lock Interactive+ - Telescoping pins, highly pick and bump resistant
- ASSA Abloy - Used in high-security applications worldwide
Additional Protective Measures
Beyond upgrading locks, consider these layered security measures:
- Reinforced strike plates - A bump-proof lock in a weak frame is still vulnerable to kicking
- Door reinforcement kits - Products like Door Devil protect the entire door
- Security cameras - Deter criminals and provide evidence
- Alarm systems - Even if entry occurs, alarm response limits damage
- Motion lights - Criminals avoid well-lit areas
Ready to Upgrade Your Locks?
Our security experts can assess your current locks and recommend the best bump-resistant options for your home and budget.
Testing Your Current Locks
Want to know if your locks are vulnerable? Look for these indicators:
- No security markings - High-security locks usually have branding visible
- Standard keyway - If any hardware store key blank works, it's likely vulnerable
- Age - Locks over 10 years old likely predate common bump resistance
- Builder-grade appearance - If it looks cheap, it probably is
A qualified locksmith can definitively assess your locks and identify the most cost-effective upgrades.
Final Thoughts
Lock bumping is a real technique, but it's just one of many ways a determined criminal could attempt entry. The good news is that protection is affordable and widely available. Even mid-range locks from reputable manufacturers now include bump-resistant features.
Focus on a layered security approach: good locks, reinforced doors, visibility deterrents, and alarm systems. No single measure is perfect, but together they make your home a significantly harder target.
