What Is a Door Latch Shim and Why Every Locksmith Needs One

If you've spent any time in the locksmithing trade, you've almost certainly faced the frustration of a spring latch lockout. The customer is locked out, the clock is ticking, and the last thing you want to do is drill out a perfectly functional lock. That's exactly where a door latch shim becomes your most valuable weapon, a low-cost, non-destructive entry tool that every professional should have within arm's reach.

In this guide, we'll break down exactly what a door latch shim is, how it works, which material separates professional-grade tools from the junk, and why the Pro Door Latch Shim 6pc System by Axiom Entry has become a go-to kit for entry specialists across North America.

What exactly is a door latch shim?

A door latch, also called a latch bypass tool, latch slip, or loiding tool, is a thin, flexible strip of material designed to slide between a door and its frame, push back the angled spring latch bolt, and allow the door to open without using a key. The technique mimics the old "credit card trick" that most people have heard of, but uses purpose-built materials engineered for the task.

Spring latch bolts are the most common residential and commercial door hardware in use today. Unlike a deadbolt, which requires a key or thumb-turn to retract, a spring latch automatically retracts when the door closes and holds the door shut under spring pressure. This design is convenient for everyday use, but it also creates a predictable vulnerability: if you can press the angled face of the latch back into the door, the lock disengages.

A shim exploits exactly that mechanism. Inserted at the correct angle into the door-to-frame gap and slid toward the latch, it applies gradual pressure to the latch's sloped face, compressing it back into the door body until the door swings free. In trained hands, the whole operation takes seconds with zero damage to the door, frame, or hardware.

Why material matters more than people think

Not all latch shims are built equal. The material determines everything: how thin the tool can be, how it flexes under pressure, how many times it can be reused before it fails, and whether it can navigate tight tolerances without snapping or cracking on the job.

Three materials dominate the market:

Super Mica is the key differentiator in the Axiom Entry kit. It's a high-performance synthetic mineral composite that is simultaneously thinner, more flexible, and tougher than either shim steel or standard plastic. It bends without cracking, slides without binding, and bounces back to its original shape after use, making it a genuinely reusable professional tool rather than a disposable consumable.

Spotlight: Pro Door Latch Shim 6pc System by Axiom Entry

When it comes to choosing a latch shim kit for serious professional use, the Pro Door Latch Shim 6pc System (SKU: AXE-6) by Axiom Entry is one of the best values on the market. This kit delivers professional-grade performance that makes it an easy addition to any locksmith's toolkit.

The kit ships with six reusable shims across two precision thicknesses: three at .015 inches and three at .020 inches. This dual-thickness design is a deliberate and practical choice. Tighter residential door frames with narrower gaps call for the thinner .015-inch shims, which can slip into spaces where a thicker tool simply won't fit. Older or slightly warped commercial door frames, which tend to have looser tolerances, are easily handled by the .020-inch variants. Having both thicknesses in your bag means fewer situations where you arrive on a job and find yourself reaching for a tool you don't have.

All six shims are made from the premium-grade Super Mica material described above, and the kit includes a carry case to keep them organized and protected between calls. Field professionals who have used this kit consistently praise the balance between thinness and structural rigidity. The shims feel almost impossibly slim in the hand but hold their shape under real working pressure without any flex fatigue.

Who is this kit designed for?

• Locksmiths performing residential and commercial lockout calls who need a fast, non-destructive first option before escalating to picks or drills

• First responders and emergency services who need rapid, clean entry to premises where every second counts

• Security consultants and penetration testers are assessing the physical access vulnerability of spring latch hardware

• Property managers and facility teams who need a non-destructive entry option when tenant keys go missing

• Tactical and law enforcement entry professionals who require tools that leave zero trace behind

Pro tip: Always carry at least one shim of each thickness. Door gaps vary enormously even within the same building, and having the wrong size can add minutes to a job that should take seconds.

When should you use a latch shim vs. other bypass methods?

Latch shims are not a universal solution; they work specifically on spring latch bolts (the type that automatically latch shut when the door closes). They will not work on deadbolts, which require key retraction, or on latches protected by a latch guard or security plate. Understanding this distinction is critical to using the tool correctly and professionally.

Here's a quick decision framework for the field:

1. Spring latch, accessible gap, no guard plate → reach for the shim first. It's the fastest and cleanest option available.

2. Spring latch with a latch guard → shims won't work here; consider lock picks or bump keys as the next step.

3. Deadbolt only → shims are not applicable; move to picking or destructive entry as appropriate.

4. Misaligned or sticky latch that won't fully retract → shims can also help here as a mechanical assist to free a malfunctioning latch bolt.

Why quality tools protect your reputation

In the locksmithing trade, your reputation is your business. A scratched door frame, a bent latch bolt, or a cracked plastic card stuck in a customer's door gap is unprofessional and avoidable. Investing in proper bypass tools like the Axiom AXE-6 system isn't just about convenience; it's about delivering a clean, damage-free result every single time.

Real users in the field agree. Reviews consistently praise the shims as "very thin but also very strong," with one entry specialist noting they are "a must-have in your entry specialist bag" that work "extremely well" straight out of the box.

Final thoughts

A door latch shim might be one of the smallest tools in a locksmith's kit, but it frequently earns its place as one of the most-used. The ability to open a spring latch door quickly, cleanly, and without any damage is a skill that separates a reactive tradesperson from a polished professional, and having the right tool to execute that technique every time is what makes the difference in the field.

The Pro Door Latch Shim 6pc System by Axiom Entry gets the fundamentals exactly right. Super Mica construction that genuinely outperforms plastic and steel alternatives, two precision thicknesses that cover the full range of residential and commercial door types, six reusable shims that will last through hundreds of jobs, a carry case for organized transport, which makes adding it to your toolkit a complete no-brainer.

Whether you're a seasoned locksmith looking to upgrade from improvised bypass tools, a first responder building out your entry kit, or a security professional who needs reliable non-destructive access tools on demand, this system belongs in your bag. Don't wait for the job that exposes a gap in your toolkit. Pick up the Axiom Entry AXE-6 from CLK Supplies today and be ready for whatever comes next.