How to Break Into a Metal Filing Cabinet

Introduction

Metal filing cabinets are very common in offices and homes for securely storing important documents and valuables. However, there may come a time when you need to access the contents of a locked metal cabinet that you don’t have the key or combination for.

Breaking into a locked filing cabinet should only be done as a last resort and with authorization if it’s not your own. There are various legal and ethical issues to consider. That said, there are ways to gain entry with some simple tools and techniques. This guide will walk you through several methods, from least destructive to most invasive, to break into a metal filing cabinet without damaging its contents.

FAQ About Breaking Into Metal Filing Cabinets

Is It Illegal to Break Into a Filing Cabinet?

Technically, yes in most regions it is illegal to force open a locked container like a filing cabinet that you don’t own or have authorization for. You could be charged with criminal damage or trespassing. It’s best to get consent from the cabinet’s owner before attempting to open it without the key.

What’s the Easiest Non-Destructive Way Into a Locked Cabinet?

The easiest non-destructive method is to try picking the cabinet’s lock using lockpicking tools. This requires some skill but won’t damage the cabinet. Other simple options include trying known default combinations or looking for a factory-set bypass key hidden on the cabinet.

What are Some Ways to Get Into a Cabinet Without Picking the Lock?

You can drill out the cabinet’s lock mechanism; use a pry bar or jimmy tool to pop open the drawers; remove the drawer entirely to access the contents from the back side; or as a last resort, cut through the side, top or back panel using tin snips or a nibbler tool. All of these methods will damage the cabinet to some degree.

What Damage Can I Expect if I Have to Forcibly Open a Filing Cabinet?

Forced entry usually results in some cosmetic damage at minimum, such as scuff marks or small dents. Drilling the lock leaves visible holes. Severe prying can warp drawers and jamb the slides. Cutting access panels will leave obvious cut marks and require repairs for secure storage again. So damage is likely but can be minimized.

What About Fireproof/Waterproof Cabinets – Can Those Still Be Broken Into?

Yes, specialized safe-like cabinets can still be breached using most of the same techniques, but extra tools or force may be required. Fireproof cabinets have double walled, heat resistant construction that resists drilling and cutting. Waterproof safes may need to be opened underwater to equalize pressure. But with enough determination and the right tools, nearly any cabinet can be opened.

How Can I Resecure a Filing Cabinet After Breaking Into It?

If the cabinet is still functional after breaking in, you’ll want to replace any broken locking mechanisms and latches. Damaged drawers may need repair. Any cut access holes will need to be covered with metal plates and re-welded or professionally repaired for security. Scuffs can be masked with matching paint. So while it is possible to refurbish a filing cabinet after forced entry, extensive repairs may be required.

Tools Needed to Break Into Filing Cabinets

To minimize damage to the cabinet, start with simple non-destructive methods using the following basic tools:

• Lockpicking set – Including rakes, tension wrenches and lock picks to try manipulating the lock open through the keyway. A basic starter set can open many common locks with practice.
• Flashlight – For illuminating the lock mechanism while picking or viewing internal access points while drilling.
• Small mirror or inspection scope – Lets you view the lock pins and mechanism to see what you are doing while picking the lock.
• Tweezers or picks – Skinny tweezers, dental picks and lockpick extractors can reach into the keyway and serve as probes and manipulation tools for lifting pins.

If lockpicking efforts fail or prove too challenging, be prepared to drill or pry the cabinet open:

• Power drill with bits – A variable speed drill for metal makes quick work of drilling out most cabinet locks. Have small drill bits from 1/16″ to 1/4″ ready.
• Pry bar or jimmy tool – A strong pry bar gives good leverage for popping open drawer slides or bending panels. Automotive door jimmy tools work well too.
• Hammer – For driving in pry bars and forcing open seized drawers. A rubber mallet reduces noise and marking.

And for invasive but effective forced entry, have these metal cutting tools ready:

• Tin snips or nibbler – For cutting access holes in sheet metal. Aviation snips in straight, left and right profiles allow clean cuts.
• Hacksaw – A fine-toothed hacksaw blade for backup cutting. Goes slower but fits in tighter access spots.
• Dremel or rotary cutting tool – Small grinding or cutoff wheels cut thin gauge sheet metal quickly.
• Sheet metal shears – Compound leverage models can cut 18 gauge steel filing cabinets easily.
• Bolt cutters – For cutting off padlock hasps if cabinets use them instead of built-in locks.
• Pliers and screwdrivers – For removing access panels, locks and handle hardware. Needle nose pliers handy for reaching into tight spots.

Non-Destructive Entry Methods

Try these simple, non-damaging methods first to open a locked filing cabinet:

Look for Hidden Factory Key Overrides

Some filing cabinets have factory default keys hidden inside the cabinet, often taped up behind drawers. Check thoroughly for any small keys stuck up under slides, at back corners or inside the lock cavity itself. These will override the lock and allow full access if still in place.

Try Known Master Combinations

Many cabinet manufacturers set them to simple to remember combinations that are rarely changed after delivery. Common factory standards include:

• 25-25-25 or 50-25-50
• 10-20-30
• 35-45-55
• 0-0-0 or 1-1-1

Cycle through trying several of these combinations first before attempting any forced entry. You may get lucky with one of the common defaults still in use.

Manipulate the Lock with Lockpicking Tools

With some practice and skill, many filing cabinet locks can be manipulated open using lockpicking tools without causing any damage. This is done by lifting the lock’s internal pins to the shear line where they will allow the lock to open.

Follow these steps to safely attempt picking a filing cabinet lock:

1. Examine the lock face and keyway first. Look for signs of security pins that complicate picking. Most will use standard pin tumblers though.
2. Slide in a tension wrench to apply rotational tension, keeping pins at shear line. Light tension only to start.
3. Insert pick and scrub across pins back and forth, tapping gently to set them. Feel for pins binding.
4. Once binding pin is felt, lift gently and apply more tension to hold pins set. Repeat for each pin stack.
5. When all are set, the lock should turn open if in proper shear alignment. Ease off tension.
6. If needed, a second pick can be used to rake pins quickly while applying tension.

With practice locks can be “raked” open very quickly. But be cautious forcing. Stop if pins won’t set right to avoid damage.

If you don’t have formal lockpicking training, consider hiring a professional locksmith to attempt non-destructive entry before you cause damage trying to pick it open yourself. Their experienced skills may open the cabinet immediately.

Low Impact Destructive Entry Methods

If you’ve exhausted the simple non-destructive methods and need to gain access, try these techniques that will cause some minor repairable damage to the cabinet:

Drill the Lock Cylinder

Drilling a lock cylinder is a quick way to disable the locking mechanism. This will damage the lock itself but not the surrounding cabinet if done carefully. Follow these steps:

1. Examine the lock’s shape and measure spacing around cylinder. Pick small drill bit accordingly.
2. Mark drill point on face of the lock down center above the keyway. This is where the locking pins are.
3. Use eye protection and gently drill pilot hole, letting drill do the work. Don’t push too hard.
4. Drill slowly through inner mechanisms and then into lock cylinder. Bits may catch and snap.
5. When cylinder spins freely, lock disabled! Insert flathead screwdriver and turn lock open.
6. Cabinet will now open but lock is destroyed. It can be replaced or just left empty if needed.

Be very gentle drilling to avoid damage beyond just the lock cylinder itself. Most filing cabinet metals are thin and the sides of the lock collapse easily with too much force.

Bypass the Locking Rods

Many filing cabinets use sliding locking rods behind the drawers to hold them locked. These can be disengaged:

1. Identify where lock bars are using a flashlight. Look inside lock chamber if needed.
2. Use a bent-tip wire or hook tool to pull rods back towards lock to disengage.
3. Alternately can pry forward and outwards gently to pop unlocked. Don’t bend them fully.
4. May need pliers or picks to reach in and manipulate rods. Pull firmly but gradually.

Once the sliding lock bars are retracted, the drawers will be freed up to pull open even with broken lock. The rods can be bent back in place after to resecure cabinet.

Pop Drawers Open with Pry Bar

For stone-like security, filing cabinets are rarely this strong, so persistent prying can flex the metal frames and pop stubborn stuck drawers open:

1. Examine drawer frame and slide rails, looking for lock bars. Also check for spots with wiggle-room to pry.
2. Insert pry bar tip into seam between drawer front and cabinet frame. Protect surface with cloth.
3. Firmly but slowly increase prying force with smooth, constant pressure. Don’t bend too far.
4. Drawer will suddenly pop free when it un-sticks or flexing metal fatigues. Be prepared and pull open.
5. May need to pry both sides to free fully. Don’t damage slides by bending them.

Some minor scuffs or small dents may happen, but the drawer will be opened. Bent slides may need replacement or realignment if the prying is too aggressive though. Go slowly to avoid worse damage.

Remove Entire Drawer to Access Contents

With no way into a stubborn tight lock, removing the entire drawer gives full access:

1. Fully extend drawer and examine rails to see where attached. Look for clip points.
2. Release any clips present by prying or cutting carefully. Protect surfaces.
3. Support drawer up into cabinet and out past rails, like lifting it off a shelf.
4. Drawer will detach from slides once pulled totally free, giving you full access.
5. Reattaching may require new drawer clips or sliders. Rivets may need drilling out.

Again protect surfaces and use care, but with some effort the drawer will separate and grant access. Use this method as a last resort before cutting, as the drawer will likely not easily reattach without repairs.

Destructive Forced Entry Methods

When less invasive methods fail or are not feasible, destructive forced entry using cutting tools is an assured way to get into a metal filing cabinet. Damage will obviously result, sometimes severe, but contents will be accessed. Be prepared to need extensive repairs afterward. Use common sense – don’t damage more than necessary.

Cut or Grind Access Hole

Cutting a small access hole either gives a view inside or a way to reach in to open the lock:

1. Pick spot for hole based on viewing needs or ease-of-access to lock. Near top or back best to hide later.
2. Mark cut lines with marker and magnet to contain hole. Protect nearby surfaces from damage.
3. Use an approved cutting method – tin snips, nibbler, Dremel etc – based on available tools and metal thickness. Go slow.
4. Penetrate top layer gradually, then cut hole outline deeper through layers carefully. Smooth edges when able.
5. Hole should give either visual access or a way to insert tools to disengage lock and open cabinet.
6. Any cut metal filing cabinet will need repair plates welded over holes and repainting to restore security.

Be very cautious cutting near lock mechanisms or slides to prevent worse damage. Start small holes only as needed – they can always be enlarged if not enough access.

Cut Hasp to Remove Padlock

If the cabinet uses an external padlock on a hasp:

1. Examine padlock and hasp thickness to determine best cutter option – bolt cutters, hacksaw etc.
2. Most hasps are relatively thin and easily cut with good bolt cutters in one snip.
3. Cut cautiously through full thickness of hasp until padlock separates. Pry remains free.
4. The cabinet will now open but hasp and padlock remnants will need replacing and repairing holes created.

Padlocks provide only minimal security on filing cabinets. Cutting them is quick but beware ‘- the hasp damage may allow the cabinet to be opened even when “relocked” until repairs are made.

Cut Door Handle to Open latched Cabinet

If cabinet has simple handle latches only keeping it closed:

1. Examine handle shape and attachment method – likely spot welds or simple screws.
2. Pick a point between handle and door to cut metal with aviation snips or a hacksaw. This only needs to go through outer skin.
3. Make cuts to slice handle exterior free from door. Penetrate carefully toward any hidden fasteners.
4. The handle will eventually detach completely, allowing the unlocked door to be pulled open.
5. Handle will need repairs and holes created will need filling and paint touch up to make secure again.

Latching handles usually just attach on the outside only and can be cut apart relatively easily. Have patience and go slow to limit damage spread.

Severe Damage Methods (Avoid if Possible)

These methods risk ruining the cabinet and should only be used as an absolute last resort:

• Using an abrasive chop saw or large angle grinder to cut through multiple sides and access contents. Will require extensive repairs and replacement panels.
• Heavy pry bars and hammers to bend panels and brute force open. High risk of frame damage.
• Thermo torches to literally burn a hole through very sturdy safes. Uses intense heat so potential for fire and interior damage.

Avoid ruining the cabinet entirely if other methods are available. Try to minimize the damage only as needed to actually get inside and remove the contents safely.

Protecting Contents and Cleanup

• Once open, carefully remove all contents to a secure area before attempting repairs.
• Use drop cloths and surface protection when cutting or prying to minimize scuffs and marks.
• Wear gloves handling sharp cut metal edges and safety glasses for eye protection.
• Drilling and cutting will produce metal shavings and dust. Vacuum thoroughly before replacing contents.
• Repair any disabled locks, latches or handles to restore security after accessing the cabinet.
• Fill holes from cutting or drilling with epoxy or metal plates welded over. Sand and paint with matching color.
• Attempt to repair any bent slides, frames or misalignments before returning contents.
• Consider upgrading security measures, like adding a high security lock, to compensate for any lasting damage.

Final Thoughts

Breaking into a metal filing cabinet should only be done with the authorization of the owner, or by legal intervention in extreme cases. Minimize damage only as needed to gain access to contents. Be prepared for extensive repairs afterward to safely re-secure the cabinet. Whenever possible, work with professional locksmiths and follow legal processes.

FAQ

Is picking a filing cabinet lock illegal?

In most regions manipulating open a lock is considered illegal without ownership or consent, as it allows access similar to breaking in. Filing cabinet locks are generally not considered secure enough to exempt from lockpicking laws.

What method usually works to open old cabinets in storage?

For cabinets that have been sitting untouched, trying factory default combinations is most effective, since many are never reset after first installation. Failing that, drilling the old lock is least destructive.

How do I open a 3-drawer vertical cabinet that’s locked?

Vertical cabinets have distinct access points. Trying all default combos first. Then inspect the drawers for locking bars to release via the sides. Finally drill or pry the central lock itself keeping the drawers secured.

What if I can’t repair the damage after breaking into my cabinet?

Damaged components like locks and bent frames may need complete replacement if unable to be fixed or straightened out. Cut panels often require professional welding and refinishing. Consider buying a replacement cabinet if repairs exceed replacement cost.

What can I fill holes with and repaint so they’re not noticeable?

Small holes can be filled with metal epoxy for a durable fill and touch up painted. Larger holes are best repaired by welding in clean metal patches, grinding smooth, then painting with an exact matching color.