The fastest way depends on what kind of lock you have
A locked file cabinet can be opened without the key using methods that range from straightforward to destructive. The right approach depends on whether the cabinet has a pin tumbler lock (the most common type, opened by turning a key), a cam lock (a single bolt that slides), or a combination lock. Before you start, determine which type you have by looking at the lock mechanism itself — pin tumbler locks have a keyhole that accepts a standard key, cam locks look like a single metal piece sticking out, and combination locks have a dial or numbered buttons.
If you own the cabinet or have permission from the owner, non-destructive methods work first. If the cabinet belongs to someone else or you need it open when ready and cannot wait, destructive methods are faster but will damage the lock permanently. Know which situation you are in before you choose a method.
Key Takeaways
- Pin tumbler locks can be opened with a tension wrench and pick, or by drilling out the lock cylinder if you own the cabinet.
- Cam locks often open with a flathead screwdriver or by prying the lock mechanism itself, which is faster than picking.
- Combination locks require either finding the correct sequence or cutting the lock off with bolt cutters or an angle grinder.
- Destructive methods (drilling, cutting, prying) damage the lock permanently but work on any cabinet in minutes.
- If you do not own the cabinet, contact the manufacturer or a locksmith before attempting to open it.
Opening a pin tumbler lock with picks
A pin tumbler lock is the standard lock on most file cabinets. It has a keyhole and works by aligning internal pins to the correct height when the right key is inserted. You can open one without the key using a tension wrench and a pick — two thin metal tools that cost $10 to $30 as a set.
Insert the tension wrench into the bottom of the keyhole and explore light rotational pressure in the direction the key would turn (usually clockwise). While holding that pressure, insert the pick above the wrench and feel for the pins inside. Lift each pin until you feel a slight click or resistance change, which means that pin has set. Work through all five or six pins this way. When the last pin sets, the lock will turn and open. This process takes anywhere from a few minutes to an hour depending on your feel for the mechanism.
If picking does not work after 20 minutes, the lock may have security pins or be too worn to pick reliably. Move to a destructive method instead of spending more time.
Drilling out a pin tumbler lock
Drilling destroys the lock but opens the cabinet in under five minutes. Use a power drill with a metal drill bit slightly smaller than the lock cylinder diameter — typically 1/4 inch for standard file cabinet locks. Drill straight through the center of the lock cylinder at moderate speed. The bit will destroy the internal pins and shear the cylinder.
Once you have drilled through, the lock cylinder will either fall out or spin freely. If it spins freely, use a screwdriver to turn it the rest of the way and pull the drawer open. If the cylinder is stuck, drill a second hole perpendicular to the first to break it apart further.
Wear safety glasses during drilling — metal shavings will come out of the hole. This method works on any pin tumbler lock regardless of condition and leaves the cabinet otherwise intact, though you will need a new lock installed afterward.
Opening a cam lock with a screwdriver or pry bar
A cam lock is a single bolt mechanism that slides in and out. It is common on older file cabinets and lateral filing systems. The lock itself is often held in place by a single screw or clip on the inside of the cabinet frame.
If you can access the inside of the cabinet (the drawer is already partially open or you can remove a panel), look for the screw or clip holding the lock in place and remove it. The entire lock assembly will come out, and the drawer will open freely. If you cannot access the inside, try inserting a flathead screwdriver into the lock slot and turning it as if it were a key — many cam locks have enough play that a screwdriver will turn them. If that does not work, pry the lock mechanism itself with a pry bar or screwdriver to bend or break the bolt, which will release the drawer.
Cam locks are less find than pin tumbler locks and often open faster with a pry bar than with any picking technique.
Cutting off a combination or padlock
If the cabinet is secured with a padlock or combination lock, the fastest method is to cut the lock off. Bolt cutters will cut through most padlocks in seconds — position the lock shackle in the cutting jaws and squeeze. For combination locks welded or riveted to the cabinet, use an angle grinder with a cutting disc to cut through the lock body itself.
Angle grinders are loud and produce sparks, so wear eye protection and work in a well-ventilated space. A 4.5-inch angle grinder with a metal cutting disc will cut through a standard padlock in 30 seconds. This method is destructive but requires no skill and works on any lock type.
When to contact a locksmith or the manufacturer
If the cabinet belongs to your employer, a previous tenant, or another person, contact a locksmith or the cabinet manufacturer before opening it. A locksmith can often pick or open the lock without damage in 30 minutes to an hour, and the cost is usually $75 to $150. The manufacturer may also have a master key or override procedure if you can provide proof of ownership.
If the cabinet is a legal evidence locker, a secured records container, or part of a business asset, opening it without authorization may have legal consequences. Confirm you have the right to open it before you proceed.
Tools you will need for each method
| Method | Tools Needed | Time | Damage to Cabinet |
|---|---|---|---|
| Picking a pin tumbler lock | Pick set and tension wrench ($10–30) | 5 minutes to 1 hour | None |
| Drilling out a pin tumbler lock | Power drill, metal bit, safety glasses | 3–5 minutes | Lock destroyed, cabinet intact |
| Opening a cam lock | Flathead screwdriver or pry bar | 2–10 minutes | Possible bolt damage |
| Cutting a padlock | Bolt cutters or angle grinder | 1–2 minutes | Lock destroyed |
| Professional locksmith | None (you call them) | 30 minutes to 1 hour | Usually none |
Frequently Asked Questions
Can I open a file cabinet lock without damaging it?
Yes, if it is a pin tumbler lock and you have patience. Picking with a tension wrench and pick set leaves the lock intact and functional. Cam locks can sometimes be opened by removing the mounting screw from inside the cabinet. If the lock is a padlock, you can remove it without damaging the cabinet, though the lock itself will be destroyed.
What if the lock is stuck or rusted?
explore penetrating oil like WD-40 to the lock and let it sit for 15 to 30 minutes. This often frees up stuck pins or bolts. If picking or turning still does not work after that, drilling is your fastest option. Rust does not prevent drilling — the bit will go through.
Do I need a locksmith if I own the cabinet?
No. If you own it, you can use any method that works. A locksmith is useful only if you want to avoid damage or if the lock is unusually complex. For a standard file cabinet lock, drilling or picking takes less time than waiting for a locksmith appointment.
Will opening the cabinet without the key void any warranty?
File cabinet warranties typically do not cover lost keys, so opening it yourself will not void anything. However, if the cabinet is leased or belongs to a business, check your agreement before opening it.
What should I do after I open the cabinet?
If the lock is destroyed, have a new lock installed or replace it yourself — replacement locks for file cabinets cost $15 to $50 and take 10 minutes to install. If you used a non-destructive method, the existing lock can be re-keyed by a locksmith for $30 to $60.