The Definitive Guide To Door Knob Screw Sizes: Understanding The Intricacies

door knob screw sizes

The size of a door knob screw depends on the type of door knob being installed. Standard interior door knobs usually require a screw measuring 1-1/2 in length, while exterior door knobs with a threaded spindle typically need a longer screw, measuring 2-1/2 or 3. Door knobs with a cylinder lock will often use much shorter screws, ranging from 1/2 to 2 in length.

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Standard interior door knobs

When choosing a door knob, the main thing to consider is what you need it for. There are two main categories: indoor and exterior door knobs. Interior door knobs are designed to be used inside the home and come in various shapes, sizes, and finishes.

Passage Knobs

Passage knobs are used in any room that does not need to be locked, such as storage or laundry rooms. They typically come without a lock and are meant to connect rooms.

Privacy Knobs

Privacy knobs are designed for rooms that require privacy, such as bedrooms and bathrooms. They have a locking mechanism located on the inside of the room to prevent outside access.

Dummy Knobs

Dummy knobs, also known as decorative knobs, are merely for decorative purposes or to provide the simple function of being a handle. They are often used on cabinets or closet doors.

Measurements

To ensure you get the right size of the door knob, you need to take three measurements: the diameter of the borehole, the distance from the hole to the door's edge (the backset), and the thickness of the door.

  • The borehole diameter for standard residential doors is typically 2 ⅜" or 2 ¾".
  • The backset is usually 2⅜ or 2¾ inches for interior doors.
  • Interior doors are generally around 1 3/8" thick.

With these measurements, you can choose a door knob that matches your specific needs and fits your door perfectly.

Styles and Finishes

When choosing a style for your interior door knob, consider the overall aesthetic of your home. You can opt for something utilitarian or more decorative, depending on the room. Common finishes include white metal, brass, iron, bronze, satin nickel, chrome, and oil-rubbed bronze.

It is also essential to keep a uniform appearance and consistent style throughout your home. You can achieve this by matching all your door knobs and hinges or opting for an eclectic look by choosing different door knobs for each door.

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Exterior door knobs

The size of door knob screws depends on the type of door knob being installed. For most exterior door knobs with a threaded spindle, the screws are longer, measuring 2-1/2" or 3" in length and between 5/32" and 3/16" in diameter. If the door knob has a cylinder lock, the screws will be much shorter, measuring between 1/2" and 2" in length and between 5/32" and 3/16" in diameter.

When choosing an exterior door knob, it is important to consider the size of the door knob diameter, which is typically either 2 3/8 inches or 2 3/4 inches. These knobs usually fit doors that are between 1 3/8 inches to 1 3/4 inches thick. Therefore, you should measure the diameter of the door knob opening and the width of the door to ensure that the selected door knob will cover the entire opening and reach across the door's width.

Some exterior door knobs may also come with specialty screws in varying sizes. For example, vintage-style door knobs may require set screws with a 32 TPI x 1/4" diameter width, which is a common thread size for holes in old-style door knobs. Additionally, it is always recommended to keep the original screws that come with the knobs and purchase additional screws of the same size in case any are lost or damaged.

When installing an exterior door knob, it is crucial to have the right tools, such as a screwdriver, drill, and a drill bit that is slightly bigger than the size of the screws. The process involves drilling a hole in the door, dividing the screws into two groups (one for the knob itself and the other for holding the knob onto the door), screwing in the knob, and then securing it with the remaining screws.

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Cylinder lock door knobs

Cylinder locks are a type of locking mechanism commonly used for doors. They feature pins of varying lengths inside the lock, which align correctly when the right key is turned, thus opening the door. These locks are easy to install and can be re-keyed without removing the entire lock.

When it comes to the screws used for cylinder lock door knobs, there are a few options. One type is the set screw, which typically has a size of 1/4-20 and can be purchased in packs of 20. These screws are often made of brass and are headless with a slotted head style. However, it's important to note that the length of the screws is crucial and can vary depending on the manufacturer. For interior doors, machine screws such as 8/32 or 10/24 round head screws are commonly used. The length of these screws can vary, but it's important to ensure they are not too long, as they may bottom out before the handle is tightened.

When replacing door knob screws, it is recommended to bring a matching screw from another door in your house to the hardware store to find an exact match. This ensures that the new screws will fit properly and are of the correct length.

Additionally, when purchasing cylinder locks, it is important to consider the level of security required. Basic cylinder locks may not provide adequate security for exterior doors, and it might be necessary to pair them with deadbolts or opt for more secure options such as double-cylinder deadbolts or smart locks.

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Antique door knobs

One popular style is the classic round door knob, which is both versatile and timeless. These knobs are typically made from solid forged brass and can come in a range of finishes, such as antique brass, oil-rubbed bronze, or satin nickel. You can also find hollow wrought brass versions that are more economical but still sturdy.

For a touch of sparkle, crystal door knobs are a cheerful and elegant option. Octagonal crystal knobs, for example, were popular in the late 1800s and are now available as high-quality reproductions, usually paired with a solid brass base. Round crystal knobs, on the other hand, bring a Victorian style to any space.

If you're looking for something more understated, small colonial door knobs in antique brass or unlacquered cast brass can be perfect for a colonial interior or any setting where you want the hardware to be more subtle.

Porcelain door knobs are another option, offering a rustic or refined look depending on how you style them. You can find these in pure white or jet black, often paired with plain iron rosettes. The iron shanks are typically powder-coated to resist rust.

When installing antique door knobs, it's important to keep in mind that the size of the screws will depend on the type of door knob and door. Standard interior door knobs typically use screws that are 1-1/2" in length, while exterior door knobs with a threaded spindle usually require longer screws of 2-1/2" or 3". Door knobs with a cylinder lock will often use much shorter screws, ranging from 1/2" to 2" in length.

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Door knob installation

Installing a door knob is a simple DIY project that can be done by following a few easy steps. Here is a comprehensive guide to help you through the process:

Step 1: Remove the Old Door Knob

If you are replacing an existing door knob, start by removing the old knob, latch, and strike plate. The strike plate is the rectangular metal piece on the door side with a hole for the latch. Use a screwdriver to remove the screws holding the strike plate and carefully lift it out.

Step 2: Install the Latch and Latch Plate

Place the new latch plate on top of the latch. The latch plate can be round or rectangular, depending on the door mortise (the hole for the latch). Slide the latch into the edge of the door, ensuring the flat or beveled side faces the door jamb. Use a wooden block and a hammer to gently tap the latch into place if needed. Secure the latch with screws—most latches require screws at the top and bottom.

Step 3: Attach the First Half of the New Door Knob

The new door knob will have two halves. One half will have a square steel peg protruding from its side. Insert this half of the knob first, ensuring the peg goes through the latch mechanism.

Step 4: Align and Attach the Second Half of the Door Knob

Lift the other half of the door knob and align it with the first half, ensuring the screw holes are aligned. Push the two halves together and secure them to the door with screws. Most door knobs have two screws at the top and bottom.

Step 5: Test and Make Adjustments

Test the door knob by opening and closing the door to ensure the latch functions correctly. Turn the handle to check for looseness. If the door knob feels loose, tighten the screws or use wood putty to fill any gaps around the screws.

Choosing the Right Screw Size:

The size of the screws required for your door knob installation will depend on the type of door knob and the thickness of your door. Standard interior door knobs typically use 1-1/2" screws, while exterior door knobs with threaded spindles usually require longer screws, such as 2-1/2" or 3". Door knobs with cylinder locks use shorter screws, typically ranging from 1/2" to 2" in length.

It is always recommended to keep the original screws that come with your door knob as replacements. If you need to purchase new screws, ensure they match the size and type of the original screws.

Frequently asked questions

The size of doorknob screws depends on the type of doorknob being installed. For standard interior door knobs, the screws usually measure 1-1/2” in length and can vary in diameter. For exterior door knobs with a threaded spindle, the screws are generally longer, measuring 2-1/2” or 3” in length and between 5/32” and 3/16” in diameter.

Interior door knobs typically use standard 8-32 machine screws, which can vary in length depending on the manufacturer.

You can find replacement screws for door knobs at your local hardware store or online at sites like Amazon or eBay. If you have the original screw, it is recommended to take it with you to the store to find a match.

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