Can angle grinders cut security chains?

Yes, most angle grinders can cut security chains but thicker, hardened chains significantly increase cutting time and make theft less likely.

The bottom line is that any security device, given enough time, can be cut - even anti-angle-grinder locks.

However, cutting a chain with an angle grinder is not instant, nor is it silent - or guaranteed. 

While angle grinders make for popular social media videos, they are not the most commonly used attack method by thieves. That's because angle grinders are loud and they create a lot of commotion, including a huge and obvious trail of sparks. When you're using an angle grinder, you lose awareness of what's around you. Most thieves don't want to take that risk.

In a nutshell:

• Yes — most angle grinders can cut motorcycle chains
• Cut time depends on chain thickness and construction
• The goal is to delay a thief long enough to deter them

Multiple factors are involved in a chain's effectiveness

A set of bolt-croppers can defeat a lot of the commonly used chains faster than an angle grinder and in relative silence.

See our range of motorcycle security chains designed to resist angle-grinder attacks

There are multiple factors affecting whether a thief can successfully cut your chain. The chain's thickness, hardness and shape all make a big difference to the tools that can be used and how much effort is required to defeat the security chain.

Independent tests show that heavier chains (16mm+) resist angle grinding much longer than lighter chains, often requiring multiple discs or battery changes and a longer attack time compared with smaller links.

That's why in this guide, we want to help you understand the best security chains to use and how to use them in order to slow down theft attempts.

Why angle grinders are a threat

While there's no reliable data on the tools that thieves are currently using to steal motorcycles, bicycles, and break into garages and sheds, it's easy to see why angle grinders are a threat and they're likely becoming more common.

Why bolt-cutters are limited against hardened chains

Once a chain is at 13mm thickness or thicker, bolt-cutters, even huge 36" ones, are limited in their effectiveness. It's impossible to crop our Protector 13mm security chain by hand. 

Using a quality security chain eliminates a large proportion of theft attempts, due to the fact most thieves don't possess the tools required to defeat a chain of this quality.

They might not get your bike, but unfortunately, we see a lot of substandard security when we're out and about, especially on bicycles and motorcycles. So they probably won't have to go far to get the next one.

Ditch your 10mm chain

If you have a chain that's sub-10mm thick, it'll prevent an opportunist thief but it's not going to put up much of a fight against a thief with a decent set of tools. If you take one thing from this article, it's that a 10mm security chain, especially one with flat-sided links, is not a good anti-theft device.

Why are grinders used instead

An angle grinder is an effective way of cutting metal. With the right disc, an angle grinder can cut hardened steel.

However, they create a lot of noise, sparks, and commotion. And to be honest with you, an angle grinder takes longer to defeat some chains than a set of bolt croppers. 

We've seen plenty of videos of angle grinders being used by thieves, when we think a different attack method would have been faster and more successful. Not all thieves are created equal.

Grinders are often used when a thief thinks that bolt croppers won't work. They may also think that an angle grinder is the only tool that has a chance of defeating the security being used. That's why a chain that's bolt-cropper proof and designed to resist cutting attacks means you're in the top tier when it comes to theft prevention.

What determines how easily a grinder can cut a chain?

There are multiple factors that affect a chain's ability to withstand an attack.

• The chain's thickness
• Steel quality / heat treatment
• The chain link shape
• The chain's positioning / access

Chain thickness

It might sound obvious, but usually, the thicker the chain, the more resistant it is to different attack methods, including angle grinders. 

However, not all chains are created equal, and thickness isn't the only factor that affects a chain's strength.

That said, most of the budget chain manufacturers don't produce chains thicker than 12mm, so it's easy to quickly rule out chains from these brands.

All of our chains require two cuts, so any thief trying to take on a Pragmasis Protector will need to try and crop it or cut it twice. Whereas some lesser chain links will shatter when bolt-cropped.

Steel hardness and construction

When the steel used in your security chain is hardened, it increases its ability to withstand an attack. An 11mm hardened steel chain will, most likely, perform better in attack tests than a 13mm chain that hasn't been hardened.

All of our Protector range of chains use quality European steel, which is then heat-treated and hardened. We also coat our chains with a layer that not only helps resist attack but also corrosion. This means your chain is ready to withstand an attack for years to come.

Chain link shape

Square-link chains are easier and cheaper to produce, but they are easier to attack than rounded chain links.

Hex or square links enable the jaws of a bolt-cutter to get purchase. The flat surface means they're easier to cut with an angle grinder, too.

As a general rule of thumb, if a chain doesn't have a round profile, it'll be easier to defeat. If you see a chain with a square or hex link, you know you can do better.

For more information, see our guide on how to choose the next security chain.

Access and movement

This is one of the key areas that we think is overlooked. 

If your chain is looped around your rear wheel and left on the floor, it's a lot easier for a thief to attack.

Forget about angle grinders for a minute. If the chain is on the floor, a thief can use a set of bolt-croppers in perfect conditions. One arm of the cropper is resting on the floor, with the chain in the jaws. The thief then hangs off the other arm, putting all their weight into it, to try and cut the chain.

If the chain is looped around the rear wheel but kept off the floor, a thief can't use the ground as a leverage point. They will have to hold both ends of the croppers. I'm not smart enough to do the maths on this, but effectively their cropping force will be halved.

A similar rule applies to angle grinders. If the chain is flat on the floor, the thief has a surface to work on. They can steady the chain and use the angle grinder.

However, if the chain is looped around the wheel and kept off the floor (looped around the seat on a motorcycle, for example), then the thief cannot get a steady surface to work on, nor can they apply pressure to the angle grinder while trying to cut the chain.

If you want an angle-grinder-resistant security chain, keep it off the ground!

Natural barriers

Following on from the mantra of keeping your chain off the ground, access is also an important factor.

If you secure your motorcycle in a garage, for example, you can fit a ground anchor to the floor in the corner of the garage and limit access to the chain by locating it between the ground anchor and the motorcycle.

With this approach, a thief will find it harder to get a set of bolt-croppers onto the chain and access will be limited for angle grinder attacks. Yes, they could lean over the bike and access the chain, however, they won't be ideally positioned and cutting a chain takes some considerable effort and time. Poor access reduces the effectiveness of an angle grinder or set of bolt croppers.

You can see our range of ground anchors here.

Are any motorcycle chains angle grinder proof?

No chain is truly angle-grinder proof. However, some are very angle-grinder resistant, which makes any attack slower, louder, and riskier.

Effective theft prevention is about making your asset hard to steal. This alone will deter a high proportion of would-be thieves. For those who do try, you're aiming to delay them as long as possible, so that their attack is unsuccessful.

Our 19mm and 22mm security chains are tough to defeat, even with an angle grinder.

How long does it take to cut a security chain with a grinder?

This depends on the brand of chain, the specification of your angle grinder and the disc being used.

 

Chain Type	Bolt Cutter Resistance	Grinder Resistance
Under 11mm	Low-Medium	Low
11mm hardened	Medium	Low–Medium
13mm hardened	High	Low–Medium
16mm hardened	High	Medium
19mm+ heavy	High	Higher

 

A lightweight chain, in ideal conditions, can have a link cut in under a minute. Heavy-duty chains will take longer and require multiple cuts and possibly multiple discs or battery changes.

As mentioned in the section above, if a chain is not left on the floor, it becomes much harder to attack, which makes a huge difference in the time required to try and defeat it.

A lightweight chain that could be defeated by an angle grinder in a couple of minutes will withstand an attack for over twice as long if positioned effectively with no links on the floor.

How to reduce the risk of angle grinder attacks

There are many things you can do to reduce the chances of your motorcycle, bicycle or garden equipment being stolen.

• Use a cover where possible
• Use the thickest chain you can manage
• Anchor the chain to the ground or structure
• Keep chains off the ground
• Combine with a second lock type
• When parking outside, choose a high-traffic location over a tucked-away spot

Frequently Asked Questions

Do insurers accept chains that can be cut with an angle grinder?
Insurers may offer discounts if you use quality security products. However, they do not expect anything to be grinder-proof. Most insurance companies recognise products that have been tested by Sold Secure.

Is a 16mm chain enough against angle grinders?
A 16mm security chain is a highly secure product. It can be defeated by an angle grinder, however, if kept off the floor, this attack method becomes a lot less effective.

Are battery angle grinders less effective?
A battery angle grinder doesn't have the power of a 240v wired one. However, the battery technology and power of portable angle grinders is improving, making them almost as effective as a wired grinder. 

Are square chains harder to cut than round ones?
No, a security chain with a flat surface is easier for some tools, such as bolt-croppers, to grip. Once an initial cut has been made into a chain, it becomes easier to locate the jaws.

Are disc locks safer against grinders?
Disc locks are another effective layer of security. However, there comes a point where the brake disc itself is easier to cut than a disc lock. We have seen many attacks where the thief cuts the brake disc, rather than the disc lock.

Does chain thickness make a real difference?
All chain brands differ as the manufacturers use different materials and processes to produce their chains. Here at Pragmasis, we use top-quality European steel, round links and our own hardening process to make our chains some of the toughest on the market. The thickness of the chain does make a difference to its cut resistance and also its visual deterrent.

Choosing a chain that resists angle grinder attacks

If you've read this article through, you'll now know that it's not just the thickness of a chain that matters. Where you position your chain is as important as its thickness.

You can view our heavy-duty security chains here.

If you're securing gardening equipment, we recommend looking at the highly portable 11mm and 13mm chains.

If you want portability for your bicycle or motorcycle, the 13mm is one of the most popular options.

The 16mm chain is a great blend of high security for relatively low weight and is popular with motorcycle riders, especially scooters, as you can carry the chain under the scooter's seat in the helmet storage compartment.

Our 19mm chain offers excellent angle grinder resistance and is a superb choice for static security. Pair this with a ground anchor in your garage and you've got a very secure setup for your motorcycles.

Our 22mm chain is a heavy beast and not for everyone but if you have to park your motorcycle outside, it's the strongest security chain we offer. We produce this in a single length (1.45m) but it has an oversized 'noose' ring at one end, meaning you effectively need a shorter chain. Paired with an anti-angle grinder D-lock and you've got a security setup that is very hard to defeat.

For improved theft resistance, shop our range of ground anchors here.