4 post frame rack 18U-58U

4-Post Open Frame Racks

4-Post Open Frame Racks combine the mounting security of a cabinet with the accessibility of a rack. Used in communication data centers and telecommunication room applications, these adjustable depth racks support deeper, heavier network equipment. They can be ganged with 2-Post Open Frame Racks or other 4-Post Open Frame Racks to expand existing systems.

4-Post Open Frame Racks are available with square holes or 12-24 tapped rails, in both 19” and 23” EIA panel widths. A variety of shelves and vertical cable managers are available to complete the setup. 4-Post Open Frame Racks ship flat. Assembly required.


Need a 4-Post Open Frame Rack Fast?

We stock the 7′ size. Call us and we can get your order processed immediately at 507-287-3535.

Need A More Robust Rack?

If you need a little more heavy-duty rack, check out our Security/AV Racks with sturdy construction capable of holding up to 1,000 lbs.

Features

4 Post Open Frame Rack Features

  • Available in six heights and two widths
  • Adjustable Depth Min/Max = 20.50″ / 32.50″ [521 mm / 826 mm]
  • Numbered rack spaces – front and rear
  • Channels constructed from heavy-duty aluminum extrusion
  • Heavy-duty base includes holes for securing to floor
  • Ships flat to save space
  • 50 pack of extra hardware included
  • UL listed

Rack Paint / Finish

  • Color: Black
  • Our products are finished in textured powder paint. Powder coating provides a durable high-quality finish.

4 Post Load Rating

  • 800 lbs. [363 kg.]

Industry Standards

  • EIA 310-D
  • RoHS compliant
  • UL listed

How to Order

  • Choose from a variety of  sizes – some of which are in stock.
  • Contact Us

Sizes Available

Adjustable Depth 4-Post Open Frame Racks – UL Listed

Includes: Rack with Square Hole Rails, Extra Black Rack Screws and Cage Nuts (50 pk), Assembly Instructions. Ships flat. Assembly required.

19″ EIA Part Number 24″ EIA Part Number Rack Units
RRD1903A-CN-BK* RRD2303A-CN-BK* 18U [3 ft.]
RRD1904A-CN-BK* RRD2304A-CN-BK* 24U [4 ft.]
RRD1906A-CN-BK* RRD2306A-CN-BK* 38U [6 ft.]
RRD1907A-CN-BK RRD2307A-CN-BK 45U [7 ft.]
RRD1908A-CN-BK* RRD2308A-CN-BK* 52U [8 ft.]
RRD1909A-CN-BK* RRD2309A-CN-BK* 58U [9 ft.]

*Minimum order quantity required.
Ask about tapped rail versions of the part number above.

Cable Management

4-Post Open Frame Cable Management Options

 

Besides helping improve airflow, cooling, and maintenance efficiency, superior cable management maximizes safety and increases your equipment’s performance. Efficient cable management allows workers to quickly access cables when troubleshooting and performing basic tasks. Choosing the most practical cable management organizers and accessories significantly impacts your network’s overall performance.

Emcor Enclosures offers a comprehensive range of cable management solutions, including:

  • Vertical cable management: Lacing panels and organizers with finger ducts
  • Horizontal cable management: D-ring organizers, organizers with finger ducts, cable troughs, rails, lacing panels, and lacing bars
  • Overhead cable management: Overhead cable trays
  • Other accessories: Cable ties, holders, clips, loops, and more

FAQs

How do I choose between a 2-post and a 4-post rack?

The primary differences between 2-post and 4-post racks are structure, size, and capacity, so knowing the exact type of equipment you need to house is critical. Two-post units are economical for mounting lighter-weight equipment like hubs, shelves, patch panels, and networking gear. Four-post racks have two additional posts and feature more robust construction, making them ideal for heavier equipment.

Are there specific industry standards that 4-post open-frame racks need to meet?

Emcor’s 4-post rack servers meet EIA-310-D standards, an initiative issued by the Electronic Industries Alliance. These standards outline various terms critical in the server rack industry, including front panel width, rack openings, and vertical and horizontal hole spacing. Our 4-post racks are also UL-listed and RoHS-compliant.

What are 4-post server racks used for?

Compared to 2-post designs, 4-post racks have higher load ratings, making them better suited for heavier and larger equipment. Four-post racks offer excellent cable management and are perfect for housing heavier, more valuable items like large servers, routers, switches, and patching frames. Four-post server racks also include features that can accommodate equipment with extended depths.

What is the benefit of having a 4-post open frame rack with cable management?

The open sides of a 4-post rack are highly beneficial when installing new equipment or removing old equipment for maintenance, particularly with cable management. These racks enable you to route and organize your cables quickly and efficiently. Cable management organizers and accessories compatible with 4-post units offer increased efficiency and maximum organization.

What makes a 4-post server rack more robust than other rack designs?

The extra posts make 4-post racks much more stable than their 2-post counterparts. Four-post units also contain a durable base with holes, enabling a secure connection to the floor. Heavy-duty aluminum channels add durability.

Product Type

Style

Preconfigured

Used Where

Requires Rear Attach Point

Material

Finish

Details

Sold As

Fits Rail to Rail Setting

U

Side Flange Style

Usable Space Front

Usable Space Rear

Usable Space Top

Usable Space Bottom

Usable Space Slope

Door Structure

Fits Frame Depth

Fits Frame Height

Max Usable Space Width

Max Usable Space Depth

Adds to Overall Height

Adds to Overall Width

Adds to Overall Depth

Fasteners Required

Overall Height

Overall Width

Overall Depth

Weight Load Capacity

Wedge Degree

CFM

dBA

Volts

kW

Amps

Phase

Recepticals

Plug Type

Cord Length

Airflow Direction

Locking

Hinge Side

Number of Monitors

Range of Motion

Mounting Hardware Included

Requires Laminate

Laminate

Paint Color

Shipping Weight

UL Listed

RoHS Compliant

REACH Compliant

EIA Standard

MIL Standard

Meets Attenuation Levels

Seismic Compliance

4-Post Open Frame Racks Compatible Parts

Select Part Number Description Files Read More
CMA-001-C
459281
Velcro Cable Ties (20 pk) Cable Manager Accessory Style C [Universal] STP

Files: STP

Product Type Cable Managers

Used Where Internal

Requires Rear Attach Point No

Style Accessory

Material Velcro

Fits Frame Depth Any

Mounting Hardware Included Included - If not installed prior to shipment.

Requires Paint No (Not Painted)

Requires Laminate No

UL Listed No

RoHS Compliant Yes

REACH Compliant Yes

HCMC1901-BK
464062
1U Single Sided Horizontal Cable Manager - 19” EIA UL Listed | Includes: Metal Rings and Snap-On Hinging Cover N/A

Files: N/A

Product Type Cable Managers

Used Where Front, Rear

Requires Rear Attach Point Yes

Style Horizontal Single Sided

EIA Width 19

U 1

Fits Frame Depth Any

Mounting Hardware Included Not Included

Requires Paint No (Black Only)

Requires Laminate No

UL Listed No

RoHS Compliant No

REACH Compliant No

HCMC1901D-BK
464063
1U Double Sided Horizontal Cable Manager - 19” EIA UL Listed | Includes: Metal Rings and Snap-On Hinging Cover N/A

Files: N/A

Product Type Cable Managers

Used Where Front, Rear

Requires Rear Attach Point Yes

Style Horizontal Double Sided

EIA Width 19

U 1

Fits Frame Depth Any

Mounting Hardware Included Not Included

Requires Paint No (Black Only)

Requires Laminate No

UL Listed No

RoHS Compliant No

REACH Compliant No

HCMC1902-BK
464064
2U Single Sided Horizontal Cable Manager - 19” EIA UL Listed | Includes: Metal Rings and Snap-On Hinging Cover N/A

Files: N/A

Product Type Cable Managers

Used Where Front, Rear

Requires Rear Attach Point Yes

Style Horizontal Single Sided

EIA Width 19

U 2

Fits Frame Depth Any

Mounting Hardware Included Not Included

Requires Paint No (Black Only)

Requires Laminate No

UL Listed No

RoHS Compliant No

REACH Compliant No

HCMC1902D-BK
464065
2U Double Sided Horizontal Cable Manager - 19” EIA UL Listed | Includes: Metal Rings and Snap-On Hinging Cover N/A

Files: N/A

Product Type Cable Managers

Used Where Front, Rear

Requires Rear Attach Point Yes

Style Horizontal Double Sided

EIA Width 19

U 2

Fits Frame Depth Any

Mounting Hardware Included Not Included

Requires Paint No (Black Only)

Requires Laminate No

UL Listed No

RoHS Compliant No

REACH Compliant No

HW-RSL100-PURPLE
461333
Rackstud - Mounting Hardware Purple Color for 12 Gauge Square Rails (100 pk) N/A

Files: N/A

Product Type Hardware

Requires Rear Attach Point No

Style Hardware Kit

Requires Paint No (Not Painted)

Requires Laminate No

UL Listed No

RoHS Compliant No

REACH Compliant No

HW-RSL100-RED
461332
Rackstud - Mounting Hardware Red Color for 14 Gauge Square Rails (100 pk) N/A

Files: N/A

Product Type Hardware

Requires Rear Attach Point No

Style Hardware Kit

Requires Paint No (Not Painted)

Requires Laminate No

UL Listed No

RoHS Compliant No

REACH Compliant No

RRD1903A-BK
463213
4-Post Adjustable Depth Open Frame Rack (3') - 18U, 19" EIA HxWxD = [36.00" x 20.25" x 44.50"] [914mm x 514mm x 1130mm] Usable Depth Min/Max = [20.50" https://www.emcorenclosures.com/ 32.50"] [521mm / 826mm] Weight Capacity = [800 lbs.] [363 kg.] UL Listed | Ships Flat, Assembly Required Includes: Rack with 12-24 Tapped Rails, Extra Black Rack Screws (50 pk), Assembly Instructions N/A

Files: N/A

Product Type Open Frame Racks

Requires Rear Attach Point No

Style 4-Post Rack with Tapped Rails

Material Aluminum Extrusion

Finish Textured Powder Paint

EIA Width 19

U 18

Front Flange Style 12-24 Tapped

Side Flange Style No Flange

Rail to Rail Depth Min 20.500"

Rail to Rail Depth Max 32.500"

Overall Height 36.000"

Overall Width 20.250"

Overall Depth 44.500" (Max)

Weight Load Capacity 800 lbs. Static Load

Requires Paint No (Black Only)

Requires Laminate No

UL Listed Yes

RoHS Compliant Yes

REACH Compliant No

EIA Standard EIA-310-D

RRD1903A-CN-BK
464072
4-Post Adjustable Depth Open Frame Rack (3') - 18U, 19" EIA HxWxD = [36.00" x 20.25" x 44.50"] [914mm x 514mm x 1130mm] Usable Depth Min/Max = [20.50" https://www.emcorenclosures.com/ 32.50"] [521mm / 826mm] Weight Capacity = [800 lbs.] [363 kg.] UL Listed | Ships Flat, Assembly Required Includes: Rack with Square Hole Rails, Extra Black Rack Screws and Cage Nuts (50 pk), Assembly Instructions N/A

Files: N/A

Product Type Open Frame Racks

Requires Rear Attach Point No

Style 4-Post Rack with Square Hole Rails

Material Aluminum Extrusion

Finish Textured Powder Paint

EIA Width 19

U 18

Front Flange Style Square Hole

Side Flange Style No Flange

Rail to Rail Depth Min 20.500"

Rail to Rail Depth Max 32.500"

Overall Height 36.000"

Overall Width 20.250"

Overall Depth 44.500" (Max)

Weight Load Capacity 800 lbs. Static Load

Requires Paint No (Black Only)

Requires Laminate No

UL Listed Yes

RoHS Compliant Yes

REACH Compliant No

EIA Standard EIA-310-D

RRD1904A-BK
463214
4-Post Adjustable Depth Open Frame Rack (4') - 24U, 19" EIA HxWxD = [36.00" x 20.25" x 44.50"] [914mm x 514mm x 1130mm] Usable Depth Min/Max = [20.50" https://www.emcorenclosures.com/ 32.50"] [521mm / 826mm] Weight Capacity = [800 lbs.] [363 kg.] UL Listed | Ships Flat, Assembly Required Includes: Rack with 12-24 Tapped Rails, Extra Black Rack Screws (50 pk), Assembly Instructions N/A

Files: N/A

Product Type Open Frame Racks

Requires Rear Attach Point No

Style 4-Post Rack with Tapped Rails

Material Aluminum Extrusion

Finish Textured Powder Paint

EIA Width 19

U 24

Front Flange Style 12-24 Tapped

Side Flange Style No Flange

Rail to Rail Depth Min 20.500"

Rail to Rail Depth Max 32.500"

Overall Height 48.000"

Overall Width 20.250"

Overall Depth 44.500" (Max)

Weight Load Capacity 800 lbs. Static Load

Requires Paint No (Black Only)

Requires Laminate No

UL Listed Yes

RoHS Compliant Yes

REACH Compliant No

EIA Standard EIA-310-D