Parts of a Crib: Labeled Diagram and Crib Part Names

By Jan Bay

Published July 20, 2026

The main parts of a crib usually include the headboard, footboard, two side rails, slats or spindles, mattress support, support brackets, and the hardware that holds those sections together. Convertible cribs may also include a stabilizer bar, toddler guardrail, an optional daybed rail, or full-size bed rails. This labeled diagram uses common part names found in crib manuals and parts lists in the United States.

A crib diagram can help you name a part. It cannot confirm that a replacement part fits your crib.

How to Read the Labeled Crib Diagram

Start with the four large outside sections: the headboard, footboard, and two side rails. The mattress support sits inside that frame and connects at one of the crib’s available height positions.

Crib manuals have a habit of giving simple names to parts that look anything but simple. A support bracket may also be called a corner bracket, mattress hanger, mounting plate, hook, or support arm.

After years of sorting through crib-part questions, I would start with the model label before searching for a single screw, bracket, or rail. The part name gets you into the right section of the manual. The model number tells you whether you are looking at the right crib. Use the crib terminology glossary when the manual uses an unfamiliar name.

Parts of a Crib and What Each Part Does

A basic crib frame is made from several large sections joined by smaller pieces of hardware. Convertible cribs have extra parts because the frame can later be changed into another bed style.

A crib manual may use a plain name for a part that looks much more complicated in a photograph.

Headboard, Footboard and End Panels

The headboard and footboard form the two ends of the crib. On some models they look almost identical. On others, the headboard is taller, curved, paneled, or more decorative.

A convertible crib may reuse one or both end panels in a later bed stage. Depending on the model, the front side rail may be removed or replaced with a toddler guardrail. A full-size conversion may use the crib end panels with manufacturer-specific bed rails.

Older manuals do not always use the words headboard and footboard. You may see front panel, back panel, end panel, left end, or right end instead. Check the drawings carefully because the direction can change depending on which side of the crib is facing the reader.

Side Rails, Crib Slats and Spindles

The side rails run between the two crib end panels. Cribs sold under current United States federal standards do not use traditional drop-side designs. Older drop-side cribs use different tracks, rods, moving rails, and hardware, so those parts should not be treated like pieces from a modern fixed-side crib. See the CPSC crib safety tips for current consumer checks.

The narrow vertical pieces inside a rail may be called slats, spindles, bars, dowels, or rods. These words are often used loosely, but the original manual is the best source for the name assigned to a specific crib.

Do not confuse a decorative spindle with a removable rail rod or support rod. A long metal rod along the edge of an older crib can be part of a movable-rail system rather than a normal crib slat.

Older movable-side cribs can also have specialized hardware that is harder to identify. See drop-side crib hardware identification for help recognizing those older components.

For information about spacing and damaged rail sections, see the crib slat spacing guide and the drop-side crib safety guide.

Crib Mattress Support Parts

The mattress support is the section that holds the crib mattress. It may be a metal spring frame, a flat board, a wire platform, or a metal frame with fabric or metal supports.

Many cribs have more than one mattress-height position. Brackets, hooks, bolts, or support arms connect the mattress platform to holes or mounting points inside the crib frame.

The mattress support is not the same thing as the mattress. It is also not a standard household box spring, even though people sometimes use the phrase crib box spring when searching for this part.

If the missing piece belongs below the mattress, the crib mattress support guide explains common platform styles. The metal crib mattress support frame reference covers spring frames and similar metal supports.

Crib Hardware, Brackets and Fasteners

Crib hardware includes the smaller pieces used to join or support the main frame. These may include bolts, machine screws, barrel nuts, washers, brackets, hooks, pins, cam locks, and threaded inserts.

A missing barrel nut can stop the entire assembly, but a close visual match still does not make a replacement correct. Two bolts may differ in thread pattern, length, head style, grade, or intended location.

Before naming a piece, note exactly where it came from. A bolt used at the headboard may be different from one used on the mattress support or conversion rails.

Use the crib hardware identification reference for common hardware names. The crib screw measurement reference explains the measurements commonly shown in manuals and parts lists.

Do not substitute a similar-looking fastener unless the crib manufacturer or original manual identifies the exact part and intended location.

Convertible Crib Parts

A convertible crib may include parts that are not needed during the crib stage. These pieces can include a toddler guardrail, stabilizer bar, full-bed rails, slats for the later bed, or brackets used only during conversion.

The words convertible crib do not mean that every required conversion piece came in the original carton. Some manufacturers package toddler rails or full-bed conversion kits separately.

A conversion rail is not automatically interchangeable with one from a similar-looking crib. Hole placement, rail length, fasteners, and connection points can vary between models from the same brand.

Keep the crib model number and manual with any unused conversion pieces. That small step makes the parts much easier to identify after the crib has been stored for several years.

Why Crib Part Names Vary

Crib manufacturers do not all use the same names. A mattress support bracket may also be called a hanger, hook, corner support, mounting bracket, or support arm. A stabilizer bar may appear in a manual as a crossbar, stretcher, support rail, or bottom bar.

Names can also change between production years. A newer manual for a familiar crib name may show different hardware from an earlier version.

Start with the label attached to the crib. Look for the manufacturer, model number, date of manufacture, and any style or lot number. Then match that information to the correct manual before relying on a generic parts name.

The crib parts identification guide explains how manufacturers group similar parts. You can also use the crib instructions and manuals hub when the original paperwork is missing.

What a Crib Parts Diagram Cannot Confirm

A general diagram can identify the likely name and location of a crib part. It cannot confirm thread size, strength, length, mounting angle, hole spacing, or compatibility with a particular crib.

Photographs can hide the differences that matter. A bracket may look correct from the front while having a different bend, thickness, slot length, or hole pattern on the back.

Do not use a crib with missing, loose, broken, substituted, or unverified structural parts or mattress-support hardware.

For cribs used in the United States, review the CPSC crib safety tips. To check a manufacturer or model, use the CPSC recalls and product safety warnings.

For brand-specific references, missing hardware, screws, mattress supports, and older crib models, return to the baby crib parts guide.

Questions About Crib Part Names

What are the main parts of a crib?
The main outside sections are usually the headboard, footboard, and two side rails. The crib also has slats or spindles, a mattress support, support brackets, and connecting hardware.

What is the complete side of a crib called?
The complete side section is usually called a side rail, crib side, side panel, or stationary rail. The narrow vertical pieces inside it are the slats or spindles.

What is the top horizontal piece of a crib called?
It is commonly called the top rail. A manual may also call it an upper rail or top bar.

What is the part under a crib mattress called?
It is usually called the mattress support, mattress platform, spring frame, or mattress board. The correct name depends on the crib design and the manufacturer’s manual.

What holds the mattress support inside a crib?
Depending on the design, the support may attach with brackets, hooks, bolts, hangers, mounting plates, or support arms.

What is a crib stabilizer bar?
A stabilizer bar is a horizontal piece used on some crib frames to connect or support larger sections. A manual may call it a crossbar, stretcher, bottom bar, or support rail.

Are crib parts universal?
No. Crib parts can vary by manufacturer, model number, production date, hardware design, measurements, and intended location.

What information should I collect before comparing a crib-parts listing?
Record the manufacturer, model number, production date, original manual part number, exact part location, and measurements. A matching photograph or listing title does not confirm compatibility.

Can I use a universal crib hardware kit?
A kit labeled universal is not proof that its screws, bolts, barrel nuts, brackets, or other pieces match a particular crib. Compare the crib manufacturer, model number, production date, original manual, part location, thread details, and measurements before treating any listing as relevant.

Can a labeled crib diagram identify the exact replacement part I need?
No. A diagram can help identify the general name and location of a part, but it cannot confirm that a replacement piece fits a specific crib.