He says the thicker a lock's shackle and the less it's exposed, the more secure the lock is from bolt cutters. And the kind of locking mechanism makes a difference in how easily a lock can be picked. The Master Lock Magnum keyed padlock and the Master Lock ProSeries Combination Lock both resist bolt cutters.
Abloy Protec2 PL 330 Padlock
It is one of the only locks in the world that has never been picked. It has a hardened boron alloy steel shackle to provide resistance to bolt cutters (but is not bolt cutter proof). The padlock body is brass and the shackle and body are chrome plated, so it is very rust-resistant.
The Stronghold SS100CS is a testament to this heritage. Our strongest padlock to date and the first-ever padlock to achieve LPCB Level SR4 accreditation, this is the world's strongest padlock.
Closed Shackle Padlocks
The shackles are typically thicker than average and made from hardened steel or even boron steel, which is 80% stronger. This is a bolt cutter-proof lock by design.
The Master Lock No. 185D Shrouded Padlock features a 1-15/16in (49mm) wide stainless steel body for maximum strength, reliability and corrosion resistance. The fully shrouded design minimizes shackle exposure and protects against bolt cutter attacks.
Unfortunately no lock is unbreakable or fully protective.
The Uncuttable Lock redefines theft protection with brute strength and defiance against any attempt at tampering. Secure your cargo containers and trailers with the Uncuttable Lock, and make vulnerability a thing of the past.
There are also industrial high-strength welded steel chains that are through-hardened. The larger diameters of these chains, especially the 5/8-, ¾-, and 7/8-inch sizes, are extremely difficult to cut due to their girth and hardness.
A Bramah key is made of stainless steel and has a round appearance with a crown on the top with a nib to one side. Each key comes with a protective cap to keep lint and dust from accumulating in the centre or in the cuts - both of which must be kept clear of dirt at all times.
Anti-pick locks are, conventionally, unable to be picked even by a professional locksmith. However, plenty of tools can still disable and break a lock. Nothing is ever truly impossible, just highly improbable. That said, you should feel pretty safe from being lockpicked with an anti-pick lock.
Other Lock Types That Locksmith Technicians Won't Open
Thumbprint locks or visual recognition locks are similar to smart locks because they require some IT experience to open. Some expert locksmith technicians in cybersecurity may offer services that involve opening thumbprint locks, most will not.
The Kryptonite Keeper has a combination lock, so you don't need a key. There are two lengths available and you benefit from Kryptonite's insurance offer. The Hiplok Spin is unrated for security, but it's much lighter than other chain locks and still wearable, making it a good solution for low risk environments.
As the only padlock to achieve LPCB Level SR4 and CEN6 ratings, the SS100CS is truly the world's strongest padlock, trusted across industries requiring unbeatable security solutions.
Hidden Shackle Locks
Also called puck locks, these locks have a hidden shackle. This provides higher security since the concealed shackle makes it almost impossible to pry or cut the lock. Hidden shackle locks are often installed on property gates and doors, especially where there are valuable items to be protected.
1. Litelok X3: The most angle grinder resistant bike lock overall. In my tests, the Litelok X3 was the lock that took the longest to cut on both sides. It provides very good resistance (if not quite the best), against diamond discs.
With a circular design and a closed shackle, disc padlocks are one of those locks that will likely deter any attacks using drills or cutters. Crafted from high-grade, reinforced stainless steel, it's an option that offers a high degree of safety & security.
All ABLOY® locks are based on the unique operating principle of rotating detainer discs, regarded by experts as a more secure system then pin-based locks. Inside the ABLOY cylinder, a series of discs rotate and function like those in a safe.
The Pewag security chain in particular stands as one of the strongest options available. Known for its unmatched resistance to cutting tools, this chain is built to provide maximum protection in both commercial and personal applications.
If you need to cut a bolt or you need to cut a pad lock this is the tool for you.
Try watching this video on www.youtube.com, or enable JavaScript if it is disabled in your browser. The biggest bolt cutters (36 and 42″) are usually only used by serious bike thieves. But they can crop mid-range u-locks and chains, and sometimes even the higher end locks.