Slide Locks

Complete Selector Guide

15+ Types · Sizes in Inches & mm · Materials · Installation · Security Ratings

Doors · Gates · Windows · Cabinets · Bathrooms · Patio · Garages · RVs — 2025 / 2026 Edition

A slide lock is one of the oldest and most reliable locking mechanisms in human use — a rod or bar that moves horizontally or vertically into a fixed receiver to hold a door, gate, window, or panel closed—no keys required, no batteries, no complexity. Pull back the bolt, open the door. Push it forward; you are locked in—or locked out. The simplicity is the genius.

But within that simplicity lies remarkable variety. There are more than fifteen distinct slide lock types, each engineered for a specific application, load requirement, security level, and environment. The barrel bolt that suits a garden gate is wrong for a bathroom door. The heavy-duty pad bolt is overkill and impractical for a kitchen cabinet. The chain slide lock, appropriate for a front door, provides no useful security on an outdoor shed.

This guide is the complete selector for every slide lock type. It covers all 15+ lock types, with exact sizes in both inches and millimetres, materials by environment, security ratings, installation requirements, and a precise decision guide that tells you which lock type is correct for each specific application — from bathroom privacy to farm gate security, from RV slide-out locks to child-safety cabinet latches.

1. What Is a Slide Lock? — Mechanisms & Terminology

A slide lock (also called a slide bolt, sliding latch, or sliding bolt lock) is any locking mechanism in which a bolt, rod, bar, or plate moves linearly — horizontally or vertically — into a fixed receiver (strike plate, keep, or staple) to secure a door, gate, window, drawer, or panel in the closed position. The movement is the defining feature: unlike a rotating deadbolt or a latch that pivots on a spring, a slide lock moves in a straight line.

ey Parts of a Slide Lock

Slide vs Rotate — Why Slide Locks Are Chosen

2. Master Slide Lock Selector — All 15 Types at a Glance

🔒  Category summary: Interior Slide Locks — Types 1, 2, 5, 6, 12, 13, 14 (7 types). Exterior / Gate Slide Locks — Types 3, 4, 7, 11, 15 (5 types). Speciality & Sliding Surface Locks — Types 8, 9, 10 (3 types). Total: 15 main types with additional sub-variants bringing the full range to 15+ configurations.

🔩  1. Barrel Bolt (Tower Bolt)  —  The Universal Standard

The barrel bolt — also widely known as a tower bolt in the UK and Commonwealth countries — is the most common slide lock in the world. It earns that title through a combination of simplicity, reliability, availability, and unmatched versatility. The cylindrical bolt slides horizontally through a barrel guide mounted to the door face and engages a strike plate fixed to the door frame, jamb, or floor.

Barrel bolts are found on virtually every type of door: bathroom and toilet doors for privacy, garden gate doors for containment, external door bolts for additional security on outward-opening doors, shed and garage doors, and warehouse loading doors. Their surface-mounted installation requires no specialised carpentry — a drill, screwdriver, and spirit level are sufficient. The range of sizes and finishes available makes them compatible with both utilitarian and decorative applications.

💡  Barrel bolt sizing rule: choose a bolt length that is at least 1.5× the door width in inches divided by 10. For a 36-inch door: 36 ÷ 10 × 1.5 = 5.4 — round up to a 6-inch bolt. Heavier doors and more exposed applications require longer bolts for greater engagement depth.

🪄  2. Flush Bolt  —  The Hidden Door Lock

The flush bolt is the architect’s choice for double doors and French doors — it disappears completely into the inactive door leaf’s edge, making the hardware virtually invisible when the doors are closed. Unlike a surface-mounted barrel bolt (which is always visible on the door face), a flush bolt is mortised into the door edge — typically routed into a shallow channel — so that its face plate sits completely flush with the door edge surface.

Flush bolts operate vertically: one bolt engages the floor (floor receiver) and one the door head (top jamb receiver), holding the inactive door leaf firmly at both the top and bottom. This top-and-bottom engagement is what gives flush bolts their structural advantage over single-point surface bolts on tall, heavy door pairs. The mechanism is operated by a finger-lift or sliding tab recessed into the plate.

⛓  3. Slide Bolt Latch  —  Heavy-Duty Outdoor

The slide bolt latch is the workhorse of outdoor shed and gate security — heavier in construction than a standard barrel bolt, with a larger bolt diameter, thicker body casing, and more robust fasteners. Where a barrel bolt is appropriate for a garden gate or bathroom door, a slide bolt latch is designed for a timber garden shed door, a metal panel fence gate, or a heavier garage pedestrian door where greater physical resistance is needed.

🔐  4. Hasp & Staple Lock  —  The Padlock Partner

The hasp and staple is not a complete lock itself — it is the mounting system that enables a padlock to secure a door, gate, lid, or panel. The hasp is a hinged steel plate that swings over the staple (a looped steel ring fixed to the frame). When the hasp is folded over the staple, the padlock passes through the staple loop, securing both elements together. Remove the padlock, open the hasp, and the door is free.

The security of a hasp-and-staple installation is only as strong as three things: the padlock quality, the hasp material and thickness, and — critically — the length and quality of the fixing screws. A cheap hasp fixed with short wood screws into a soft timber door frame can be defeated by a single sharp kick. Quality hasps use hardened steel, close-shackle padlock compatibility, and hidden or shielded screws that are only accessible when the lock is removed.

⚠️  Hidden screw security: on a standard hasp, the fixing screws are exposed when the hasp is open — making them easy to remove by an intruder. Choose hasps with a security plate that covers the screws when the hasp is closed, or use a close-shackle padlock that sits so low it physically covers the screws. This is the single most important hasp security consideration.

⛓️  5. Chain Slide Lock  —  Partial-Open Security

The chain slide lock — commonly called a door chain or security chain — allows a front door to be opened a few inches to see and speak with a caller while preventing the door from being pushed fully open. The mechanism consists of a sliding bolt attached to a short chain: the chain end is fixed to the door frame, and the bolt slot is fixed to the door. When engaged, the chain limits door travel to approximately 2 to 4 inches, regardless of the force applied to open it.

🚪  6. Door Slide Latch  —  Simple Interior Privacy

The door slide latch is the most compact and basic slide lock for interior doors — a simple horizontal bolt in a minimal housing that mounts to the door face. It provides privacy rather than security, making it appropriate for bedrooms, home offices, laundry rooms, and secondary interior spaces where you want the ability to indicate occupancy and prevent casual entry without needing a keyed lock or a lock with a hold-open indicator.

🌀  7. Spring-Loaded Slide Bolt  —  Auto-Lock Gates

The spring-loaded slide bolt addresses one of the most common gate security failures: the gate that was meant to be latched but was left open because the user forgot, or because a child passed through and did not engage the latch. The spring-loaded mechanism eliminates this risk — when the gate is pushed closed, the spring automatically drives the bolt into the strike plate, requiring no manual engagement. The gate is always latched when closed, unless deliberately held open.

🪟  8. Sliding Patio Door Lock  —  Glass Door Security

Sliding patio doors — the glass panel doors that slide on tracks — present a unique security challenge. The standard latch mechanism built into most sliding patio doors is a handle-operated hook latch that provides only basic resistance to forced entry. A sliding patio door lock is an additional or replacement lock device that improves security substantially by adding a bolt, pin, or bar mechanism to the door frame, preventing the panel from being slid open or lifted off the track.

📐  Sliding patio door size: There is no single standard size for sliding patio door locks because they must match specific door frame profiles. Always measure the depth and height of your door frame channel before purchasing any aftermarket lock. Many manufacturers provide universal models that adjust within a range — verify the range covers your specific door.

🪟  9. Window Slide Lock  —  Sash & Sliding Frame Protection

Window slide locks secure sliding windows — both horizontal sliding sash windows and vertical double-hung sash windows — in the closed position or at a controlled ventilation opening. Unlike casement or tilt-and-turn windows (which use different locking mechanisms), sliding windows are inherently vulnerable to being pushed open from outside if the standard handle latch is the only securing device.

🗄️  10. Cabinet Slide Lock  —  Drawer & Cupboard Control

Cabinet slide locks secure kitchen cabinets, bathroom vanity drawers, medicine cabinets, filing cabinets, and display cupboards. They serve two distinct purposes in residential settings: child safety (preventing access to hazardous contents) and privacy or mild security (preventing casual access to valuable or confidential items). They are the smallest slide lock type by a significant margin.

🏗️  11. Pad Bolt (Cross Bolt)  —  Farm Gate & Heavy-Duty

The pad bolt — sometimes called a cross bolt — is the heavy-duty cousin of the barrel bolt, engineered for gates, doors, and panels that require substantially greater mechanical strength. The bolt diameter is noticeably larger than that of a standard barrel bolt; the barrel guides are heavier and more numerous; and the entire assembly is designed to withstand significant lateral force. The name ‘pad bolt’ comes from its traditional use on paddock gates, but it is equally appropriate for agricultural buildings, farm sheds, industrial storage, and heavy timber garage doors.

✨  12. Decorative Tower Bolt  —  Style With Security

The decorative tower bolt is a barrel bolt elevated to a design element. While a standard barrel bolt is a purely utilitarian piece of hardware, a decorative tower bolt is crafted with aesthetic intent — ornate finials on the bolt knob, scrollwork on the mounting plates, hand-applied antique finishes, or contemporary sculptural forms that complement high-end interior doors, bespoke cabinetry, and design-led architectural joinery. The function is identical to a barrel bolt; the execution is entirely different.

👶  13. Child Safety Slide Lock  —  Baby-Proof Protection

Child safety slide locks are engineered for one specific purpose: to prevent access by children aged 1 to 5 who have not yet developed the two-step operational dexterity required to open them, while remaining freely operable by adults. They are mandatory equipment in households with young children for securing access to hazardous cabinets (cleaning products, medications, sharp utensils), windows (to prevent falls), and exits (to prevent outdoor access without supervision).

⚠️  Window restrictor legal requirement: in the UK, building regulations require window restrictors on any openable window above 2 metres from the ground in dwellings with children. Many other jurisdictions have equivalent requirements. A child safety slide lock on windows is not optional — it is a safety-critical installation in any home with young children.

🚽  14. Bathroom Privacy Slide Lock  —  Indicator Locks

The bathroom privacy slide lock — most familiar from toilet cubicle partitions and domestic bathroom doors — provides occupancy indication as much as security. The mechanism slides to lock the door from the inside. For public toilet partition versions, this action changes an external indicator from ‘Vacant’ (green) to ‘Engaged’ (red), indicating occupancy without requiring a knock. Domestic versions prevent the door from being opened from the outside.

🔒  15. Heavy-Duty Gate Slide Bolt  —  Maximum Outdoor Security

The heavy-duty gate slide bolt is the maximum-security slide lock for external applications — the final word in slide-bolt construction for gates, barn doors, shipping containers, and perimeter-fencing gates that must withstand sustained, deliberate force, adverse weather, and potentially years of heavy use without maintenance failure. These are not domestic hardware store items — they are commercial and agricultural-grade components engineered to a completely different standard.

3. Slide Lock Sizes — Complete Reference (Inches & Millimetres)

4. Slide Lock Materials — By Environment & Application

📐  Material selection rule: match material to the wettest and most chemically aggressive condition the lock will ever encounter. A barrel bolt that is ‘mostly indoor but occasionally exposed to rain’ requires a minimum of stainless steel 304. A gate bolt in a coastal garden needs to be 316 stainless steel or hot-dip galvanised. Interior bathroom locks need to be at a minimum satin nickel or brass — not zinc alloy, which will develop white corrosion in humid bathrooms within 2 to 3 years.

5. How to Choose the Right Slide Lock — Decision Guide

6. Installation Guide — Door, Gate, Window & Cabinet

Installing a Barrel Bolt on a Door — Step by Step

• Step 1 — Choose position: typically 6 to 12 inches from the top of the door for a standard privacy bolt; 12 to 18 inches from the bottom for a bottom bolt; or both for doubled security
• Step 2 — Mark the body position: hold the bolt body against the door face at the chosen height; use a pencil to mark the screw holes through the body plate; use a spirit level to confirm the body is perfectly horizontal before marking
• Step 3 — Pilot holes: drill pilot holes at each marked position using a drill bit slightly smaller than the screw diameter — this prevents timber splitting and ensures the screws bite cleanly
• Step 4 — Mount the body: fix the bolt body with the provided screws; do not overtighten — the body must sit flat, and the bolt must slide freely after mounting
• Step 5 — Mark strike position: close the door and slide the bolt fully forward; the bolt tip will mark the door frame at the exact position where the strike must be fixed; mark this position with a pencil
• Step 6 — Mount the strike plate: fix the strike at the marked position with 2 screws; test that the bolt enters the strike cleanly with the door fully closed — adjust strike position by 1mm to 2mm if needed
• Step 7 — Test operation: slide the bolt 10 times in each direction; it should operate smoothly with no binding or catching; a small amount of candle wax or spray lubricant on the bolt barrel resolves minor friction

Installing a Hasp & Staple — Security Considerations

• Use coach bolts (carriage bolts) rather than wood screws wherever the door or frame material allows through-bolting — this multiplies pull-off resistance by a factor of 5 to 10
• Position the hasp so that when it is closed and padlocked, the screw heads are covered by the closed hasp body — preventing screw removal by an intruder with a screwdriver.
• Use a close-shackle padlock on any hasp that is exposed to outdoor attack — a standard open-shackle padlock can be cut with bolt croppers in seconds; a close-shackle padlock makes this significantly harder.
• If mounting into masonry or metal, use appropriate masonry anchors (M6 rawl bolts) or self-tapping metal screws; wood screws into a timber batten that is itself anchored to masonry.

Installing a Flush Bolt — Door Edge Mortising

• Mark the bolt body position on the door edge: the centre of the bolt body typically sits 6 to 8 inches from the bottom of the door for the lower bolt, and 6 to 8 inches from the top for the upper bolt.t
• Route the mortise: Use a router with a straight bit or a sharp chisel to cut the recess for the bolt body — the recess depth must equal the bolt body thickness, so the face plate sits flush with the door edge.e
• Chisel the receiver channel: the bolt must travel into a small channel cut in the door frame edge — mark this by closing the door and marking through the bolt ho..le.
• Install the floor receiver: for the lower bolt, install a brass or steel flush cup receiver in the floor — position precisely by extending the lower bolt with the door closed and marking the floor at the bolt tip; drill and chisel the cup receiver. ess.
• Install the head receiver: a surface-plate or mortised receiver in the door head captures the upper bolt — same marking process as floor receiver.

Replacing a Slide Bolt on a Gate Lock — Common Issues

• Most gate slide bolt replacements fail because the replacement is a different size than the original — always measure the existing bolt body length, bolt diameter, and fixing hole centre-to-centre distance before ordering a replacement. ement
• Gate bolt misalignment: if the existing strike is corroded or the gate has settled, the bolt and strike may no longer align — the strike is adjustable; slot the strike screw holes with a file or replace with an oversized strike plate before reinstalling
• For galvanised gate bolts: coat all fixing screws with zinc-rich primer, or use stainless screws, after installation,n to prevent galvanic corrosion between steel screws and the galvanised body.

7. Slide Lock Security Ratings — What They Mean

🔒  Important security reality: no slide lock type is a complete external security solution on its own. A barrel bolt on an exterior door supplements a keyed deadbolt — it does not replace it. For exterior door security, a slide bolt adds a second line of resistance only when the primary keyed lock has already been engaged. Any slide lock on an exterior door should be used in conjunction with, not instead of, a quality keyed deadbolt.

8. Speciality Applications

Garage Door Slide Lock Installation

• A garage door slide lock is a horizontal or vertical bolt mounted internally on the garage door panel that engages a bracket or slot on the door frame or guide rail — preventing the door from being raised even if the overhead door mechanism is unlocked or overridden. en
• Horizontal garage door slide bolt: mounts on the side panel of a sectional or tilt-up garage door; bolt slides into a bracket on the vertical guide rail; operated from inside; 8″ to 12″ bolt is standard
• Vertical drop bolt: drops down into a socket in the garage floor when engaged; suitable for panel-lift and tilt-up doors; prevents lift from outside
• Installation requirement: the bolt must clear the door panel guides when the door is fully closed,d but must not interfere with the door’s travel when raised — mount above the guide rail level or with a bracket that swings clear when unlocking

RV Slide-Out Locks

• RV and motorhome slide-outs are room extensions that extend from the vehicle side to increase interior space — slide-out locks secure the extended room in place and prevent retraction while parked.
• Purpose-designed RV slide-out locks mount to the slide-out frame and body junction; they are not generic barrel bolts — the geometry and mounting points are specific to the slide-out mechanism.m
• Most RV slide-out locks are either a manual pin-lock (inserted through matching holes in the slide frame) or a dedicated locking bracket designed for specific RV manufacturers’ systems.
• Generic slide lock for RV: a secondary lock for the entry door of an RV is typically a barrel bolt or chain slide lock mounted on the interior door face — a standard 4″ to 6″ barrel bolt is appropriate for RV door thickness

French Door Slide Lock

• French doors present a specific challenge: two leaves that meet in the centre with no fixed centre post. One leaf (the active leaf) has the main handle and lock. The other (the inactive leaf) must be secured independently.
• Best solution: flush bolts at the top and bottom of the inactive leaf — these engage the floor and head, holding the inactive leaf firmly without any visible hardware when the doors are closed.
• Alternative: a surface-mounted barrel bolt at the top of the inactive leaf (6″ or 8″) plus a flush foot bolt at the bottom — less neat than full flush bolts but significantly easier to install
• Double door slide lock: when both leaves must be secured simultaneously from the inside, a centre-mounted slide bolt or cremone bolt (multi-point locking rod mechanism) running vertically locks both leaves with one operation

Slide Locks for Double Doors — Both Leaves

• For double doors that both need to be lockable independently from inside: fit a barrel bolt on the inside face of each leaf — one at the top, one at the bottom of the inactive leaf; standard handle lock on the active leaf
• For double doors secured with a single mechanism: a cremone bolt (a vertical sliding rod system with top and bottom catches) operates both catch points from a single centre handle — the most elegant solution for large double doors
• Slide locks for double doors from the outside: require either a hasp and padlock on the face of the door pair, a keyed cam lock through the door face, or a mortised key-operated mechanism — surface slide bolts alone cannot be engaged from the outside.

9. FAQs: Slide locks selector

Q:  What is the most common slide lock for a bathroom door?

The most common bathroom door slide lock is the barrel bolt (tower bolt), available in 4-inch and 5-inch sizes, fitted horizontally at mid-door height (approximately 54 to 60 inches from the floor). For shared family bathrooms, a bathroom privacy slide lock with a red/green external indicator and a coin-slot emergency release is the more functional choice. Material should be satin nickel, brass, or chrome — not zinc alloy, which corrodes in bathroom humidity within a few years.

Q:  How do I replace a slide bolt on a gate?

Measure the existing bolt body length, bolt diameter, and the centre-to-centre distance between fixing holes on the existing body plate before ordering a replacement. Remove the old bolt body and strike plate. If the gate has settled and the bolt and strike are misaligned, adjust the strike position (elongate the screw holes with a file) before fitting the new bolt. For galvanised gate bolts, use stainless steel screws to avoid galvanic corrosion between the screws and the galvanised body.

Q:  What is the difference between a barrel bolt and a pad bolt?

A barrel bolt is a lighter-duty slide lock with a slender cylindrical bolt, typically 5 to 10mm in diameter, suitable for doors, bathroom doors, and garden gates. A pad bolt (cross bolt) is a heavy-duty version with a significantly larger bolt diameter (12 to 20mm), more barrel guides, heavier body construction, and through-bolt fixing — designed for farm gates, agricultural buildings, and high-load outdoor applications. Both types typically include a padlock eye, but the pad bolt is designed for a larger padlock shackle.

Q:  What size slide bolt should I use for a garden gate?

A 6-inch (152mm) barrel bolt is the standard recommendation for a residential timber garden gate. For heavier timber or metal panel gates, choose an 8-inch (203mm) slide bolt latch with a larger bolt diameter. For a farm paddock gate or a heavy driveway gate, a 10-inch to 12-inch (254 to 305mm) pad bolt with a coach-bolt fixing is appropriate. The key rule: gate bolt length should be a minimum of 15% of the gate height — a 40-inch tall gate needs a bolt with at least 6 inches of bolt travel.

Q:  Can a slide lock be used as the main exterior door lock?

No — a slide lock (barrel bolt, slide bolt latch, or similar) should never be used as the only locking mechanism on an exterior door. Slide locks are surface-mounted hardware that can be defeated by forced door flex or by attacking the strike plate screws. They are appropriate as supplementary security alongside a primary keyed deadbolt — adding a second point of resistance when used in combination. For exterior security, the primary lock must be a quality mortised deadbolt with a full-box strike plate fixed with 3-inch screws into the structural stud.

Q:  What slide lock is best for a sliding patio door?

A two-device approach is recommended: a security bar or ‘Charlie bar’ placed in the lower track prevents the door from being slid open even if the handle latch is defeated — this is the most effective primary measure. A secondary pin lock through the track frame, in the closed position, adds a second barrier. For patios accessed from outside, a keyed sliding door lock in the handle assembly is also necessary. The standard handle latch on most sliding patio doors is not a security device — it is an operational latch only.

Q:  How do I make a slide lock childproof on a cabinet?

The most effective childproof cabinet solution is a magnetic cabinet lock — the latch mechanism is entirely hidden inside the cabinet and is released only by holding a magnetic key against the outside of the cabinet door. Children cannot feel or see the mechanism, cannot operate it without the key, and cannot defeat it by pulling. A two-action slide lock (requiring simultaneous press-and-slide) is the best surface-mounted option if you prefer visible hardware. Simple single-action slide bolts mounted out of a child’s reach (at the top of a door) also work well for doors rather than cabinets.

Q:  What is a flush bolt, and when do I need one?

A flush bolt is a slide lock mortised into the edge of a door so that its face plate sits completely flush with the door edge surface — invisible when the door is closed. It is used on the inactive leaf of double doors (French doors, double entry doors) to secure that leaf at the top (into the door head) and bottom (into the floor) while the main lock secures the active leaf. If you have two-panel French doors and one panel needs to be secured without any visible hardware, flush bolts are the correct solution.

Q:  What slide lock should I use for the top of a door to keep children in?

Mount a 4-inch to 6-inch barrel bolt at the very top of the door — at approximately 78 inches from the floor or higher. This height is completely out of reach for children under 6 years old. Use a barrel bolt in chrome or brass to match the door’s existing hardware. This is the simplest and most reliable method for preventing a child from opening a door to an exterior, garage, or stairwell. The slide operation is immediately obvious to adults without any special knowledge.

10. Disclaimer

The information in this guide covers standard residential and light-commercial slide lock types and is intended for general reference and product selection. Security ratings provided are indicative only — they do not represent certified security ratings and should not be relied upon for insurance, legal compliance, or professional security specifications. For insurance-compliant security, consult your insurance provider for their specific lock requirements.

Child safety lock information is for general guidance only. Always verify that any child safety product meets the applicable safety standards for your country (ASTM F1821 in the US; EN 14428 in the EU; BS EN 14428 in the UK). A child safety lock is one component of a broader childproofing strategy — it is not a substitute for direct adult supervision.

Pool gate locking requirements vary by jurisdiction. Always verify local building codes and pool fencing regulations before selecting and installing pool gate hardware — non-compliant pool fencing and gate latching are legal liabilities in most jurisdictions and pose serious child safety risks.

Installation guidance is provided for general information — always follow the specific manufacturer’s instructions for the product you purchase. For structural or security-critical installations, consult a qualified locksmith, joiner, or building professional.

Right lock. Right size. Right material. Right installation. The simplest hardware, done correctly, delivers decades of reliable security.