Help Center

Stand on the outside of the door — the side you'd face when entering. If the hinges are on your left, it's a left-hand door. If the hinges are on your right, it's a right-hand door. For doors that swing toward you when opening, you'll need a reverse bevel designation. See our full Door Hardware Ordering Guide for detailed handing diagrams.

A reversible lock is designed to work on either a left-hand or right-hand door without modification — the latch can be flipped or rotated in the field to accommodate either handing. Most modern tubular locksets are reversible. Check the product description or contact us to confirm before ordering.

Backset is the distance from the edge of the door to the center of the borehole — the large hole where the knob or lever installs. The two most common backsets are 2-3/8" (standard on interior doors) and 2-3/4" (standard on exterior doors). Measure from your door edge to the center of the existing hole. Most locks on our site accommodate both backset sizes. See our full ordering guide for measuring instructions.

• Passage – Always unlatches from both sides. No locking. For hallways and closets.
• Privacy – Locks from inside with push-button or thumbturn. No key. For bathrooms and bedrooms.
• Entry / Keyed – Key from outside, thumbturn from inside. For exterior and security doors.
• Keyed Both Sides – Key required on both sides. For doors with glass near the lock.
• Dummy – Non-functional pull, no latch or lock. For inactive panels and decorative use.
• Storeroom – Always locked outside (key required), always free inside. For commercial storage.
• Classroom – Outside locked or unlocked by key only; inside always free. For school and office doors.

In a pair of double doors, the active door is the one used for everyday passage — it has the operating lockset or panic device and opens first. The inactive door remains closed during normal use and is held in place by flush bolts (top and bottom) or a surface bolt. Hardware like coordinators and astragals are often required to ensure the doors close in the correct sequence and seal properly.

Standard residential interior doors are 1-3/8" thick. Standard residential and light commercial exterior doors are 1-3/4" thick. Heavy commercial and fire-rated doors are typically 1-3/4" or thicker. Most locksets are designed for 1-3/8" to 1-3/4" doors. If your door is thicker, look for locks with extended spindles or contact us for options.

• Keyed Random – Lock ships with random keys. No relationship to other locks.
• Keyed Alike – Multiple locks that open with the same key.
• Keyed Different – Each lock has its own unique key.
• Master Keyed – One master key opens multiple different locks, each with its own individual key.
• Grandmaster Keyed – Hierarchical system with grandmaster, master, and individual keys.
• Construction Keyed – Temporary key for use during construction, disabled permanently when the owner's key is first used.

See our Lock Keying Service page for full details.

A single cylinder deadbolt uses a key on the outside and a thumbturn on the inside — the most common residential choice, allowing quick egress from inside without a key. A double cylinder deadbolt requires a key on both sides, making it useful where glass panels are located near the lock. However, double cylinder deadbolts can be a fire hazard if the key isn't readily accessible — always check local fire and building codes before installing. See our Deadbolt Guide.

A tubular latch is a spring-loaded bolt that installs through a round hole bored in the door face, with a smaller hole bored into the door edge for the latch face plate. It's the most common residential lock type. The term tubular lock (or bored lock) refers to the complete lockset — knob, lever, or handleset — that uses this installation method. Installation is fast and requires no special mortising of the door edge.

A dead locking latch bolt (also called an anti-shimming latch) features a small auxiliary plunger alongside the main latch bolt. When the door is fully closed, this plunger depresses against the strike plate, locking the latch bolt in the extended position so it cannot be pushed back with a card or shimming tool. This is a critical security feature on exterior doors — always look for dead locking latches on entry locksets.

A mortise lock installs inside a deep rectangular pocket (mortise) cut into the edge of the door. The lock body is housed entirely within the door, making it extremely strong and tamper-resistant. Mortise locks are standard in commercial and high-security applications and are far more durable than tubular locks. They typically include a latch bolt, deadbolt, and auxiliary features all in one unit. Professional installation is recommended if your door doesn't already have a mortise pocket.

A strike plate is the metal plate installed on the door frame that the latch bolt and/or deadbolt extend into when the door closes. It reinforces the frame and provides a secure pocket for the bolt to engage. Standard strikes are mortised flush into the frame. Extended lip strikes protect against shimming. Security strikes use longer screws (3" or more) reaching the wall stud for significantly greater kick-in resistance. Upgrading to a security strike is one of the most cost-effective security improvements you can make.

An ADA compliant door closer must be set so that the door requires no more than 5 lbs of force to open on interior doors and accessible routes. The door must also take a minimum of 5 seconds to close from 90° open to the latch position. Most commercial adjustable closers can be set to meet ADA requirements by adjusting the spring tension and sweep speed valves. Look for closers with a Size 1–4 spring range for maximum ADA adjustability.

Door closer hinges — sometimes called pivot hinges used with floor closers — are a specialized product listed separately in the hinge section of our store. If you're looking for a concealed floor closer system, contact us and we'll help you find the complete assembly including the pivot set, floor closer, and top pivot required for your door.

A tri-pack door closer includes three complete sets of mounting hardware in the box — one for regular arm (standard) mounting, one for parallel arm mounting, and one for top jamb mounting. This allows the installer to choose the most appropriate mounting method on-site based on the door and frame configuration, without ordering a separate mounting package.

• Regular arm (standard) – Closer body mounts on the door, arm bracket on the frame. Most common installation. Best for outswing doors. Provides the strongest mechanical advantage.
• Parallel arm – Closer body on the door, arm runs parallel to the door face when closed. Best when frame space above the door is limited or when a sleeker appearance is desired.
• Top jamb – Closer body mounts on the frame, arm attaches to the door face. Required for some inswing doors and situations where door-face mounting isn't possible.

When in doubt, regular arm mounting delivers the best performance for most standard commercial applications.

Back check is a hydraulic feature that slows the door when it is opened too quickly or too forcefully, engaging typically between 60–80° of the opening swing. It cushions the door to prevent it from slamming into a wall, damaging the closer arm, or injuring someone standing nearby. Back check is especially critical on exterior doors exposed to wind and on doors in high-traffic areas where people may push the door open hard.

Sweep speed (also called main speed or closing speed) controls how fast the door travels from the fully open position to approximately 10–15° before the latch engages. It is adjusted with a flathead screwdriver on the sweep speed valve on the closer body — clockwise to slow, counterclockwise to speed up. For ADA compliance on accessible routes, the door must take at least 5 seconds to close from 90° open to the latch position.

Latch speed controls the final 10–15° of door travel — the speed at which the door closes the last few degrees to positively engage the latch bolt in the strike. It is a separate adjustment from sweep speed on most commercial closers. Setting latch speed too slow can result in the door not fully latching; too fast can cause the door to slam or bounce back. Adjust carefully in small increments after setting sweep speed.

A hold open arm is an optional closer arm that includes a ratcheting or friction mechanism that holds the door open at a fixed position — typically 90° or at whatever angle the door is opened to. It's useful in high-traffic situations like loading docks or service corridors where doors need to stay open during deliveries. Important: hold open arms should never be used on fire-rated doors, which must self-close at all times per fire code.

The key is matching the mounting hole pattern on your existing closer body. Measure the distance between the mounting holes and compare to replacement models. Many major brands — LCN, Norton, Corbin, Sargent, Yale, Rixson, and Dorma — share compatible hole spacing, making direct bolt-up swaps common. Use our Door Closer Mounting Holes Chart or contact us with your existing closer's brand and model number and we'll identify the best drop-in replacement.

The power size (or spring size) indicates the closing force of the door closer, typically ranging from Size 1 (lightest) to Size 6 (heaviest). A higher number means more spring tension and more opening force required to open the door. Factors that determine the right size include door width, door weight, and whether the door is exposed to wind pressure. For ADA-compliant interior doors, use the minimum size that reliably closes and latches the door. Many commercial closers are adjustable across 2–3 spring sizes. Consult the manufacturer's sizing chart or contact us for a recommendation.