SOSS 218 Series Invisible Hing...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$70.86
$62.32
SOSS 218 Series Invisible Hinge 4-5/8" with 20 Minute UL Fire Rating

SOSS 218 Series Invisible Hinge 4-5/8" with 20 Minute UL Fire Rating

(1 review) Write a Review

Model: 218US26D
From the 218 Series Collection
Selected Finish is

In Stock (leaves warehouse same day if ordered before 3pm ET)

$70.86
$62.32
Adding to cart… The item has been added
Free Shipping on orders over $199
We price match and offer bulk discounts! Click Add to Quote. It's quick and easy.
✨
Earn points with this purchase! You can redeem points for giftcards, iPads, XBox's and more. View Rewards
Free Keying on all locks
You may also like

SOSS 218 Series Invisible Hinge 4-5/8" with 20 Minute UL Fire Rating

The SOSS 218 Series Invisible Hinge is a full size door style hinge measuring 4-5/8" and designed for wood or metal applications with a minimum door thickness of 1-3/4" to 2". Constructed of zinc and steel with nylon links for added strength and durability, this hinge opens a full 180° as a single action hinge. The model #218 now carries a 20 Minute UL Fire rating, making it suitable for hollow metal, sheet metal, tin clad, steel composite, or wood core swinging type fire doors and frames.

Key Features

  • Minimum Material Thickness: Designed for doors 1-3/4" thick, supporting full size entry applications in metal and wood.
  • Product Size: 4-5/8" hinge size delivers a flush fit and compact profile for superior appearance.
  • Heavy-Duty Construction: Made of zinc and steel materials with nylon links that add strength and durability for long-term reliability.
  • Full 180° Operation: Single action hinge design opens a full 180° for smooth, unobstructed door movement.
  • Fire-Rated Performance: Underwriters Laboratories labeled for use on hollow metal, sheet metal, tin clad, steel composite, or wood core swinging fire doors and frames with a 20 Minute rating.
  • Fire Door Hinge Requirements: Use at least one fire-rated hinge for every 20" of door height or portion thereof, or one hinge for every 60 lbs. or fraction thereof, whichever demands more hinges.
  • Hardware Included: Wood and machine screws are included for versatile installation on multiple substrate types.
  • Invisible Design: Flush fit and compact size make this hinge ideal for applications requiring smooth operation and minimal visibility when the door is closed.

Certifications & Compliance

  • UL Listed, 20 Minute Fire Rating

Technical Specifications

  • Subcategory: Hinges and Pivots
  • Commercial/Residential: Commercial
  • Product Group: Door Hinges and Pivots
  • Product Type: Hinges and Pivots
  • Duty Level: Heavy Duty
  • Electronic: No
  • Corner Type: Radius
  • Series: 218 Series
  • Collection: 218 Series
  • Product Size: 4-5/8"
  • Product Category: Door Hinges and Pivots
  • Department: Door Hardware
  • Application: Full Sized Entry, Metal, Wood
  • Min. Material Thickness: 1-3/4″
  • Fire Rating: 20 Minutes
  • Power Transfer: No
  • Closer: No
  • Counter Bored Screw Holes: No
  • Screws Included: Wood and Machine
  • Packaging: 1 / Box = 1 Each
  • Packages Per Container: 1 Each
  • Price Per: Each

Typical Applications

  • Commercial Office Buildings
  • Educational Facilities
  • Healthcare Institutions
  • Retail Establishments
  • Industrial and Warehouse Facilities
  • Multi-Tenant Residential Properties
  • Government and Municipal Buildings

Why SOSS 218?

SOSS 218 Series hinges combine zinc and steel construction with nylon links to deliver dependable strength and smooth, full 180° operation. With a 20 Minute UL Fire rating, this hinge is engineered for demanding commercial applications where fire door compliance, flush appearance, and compact size are essential.

Product Specs

Subcategory:
Hinges and Pivots
Commercial/Residential:
Commercial
Product Group:
Door Hinges and Pivots
Product Type:
Hinges and Pivots
Product Subgroup:
Invisible Hinges
Duty Level:
Heavy Duty
Electronic:
No
Corner Type:
Radius
Series:
218 Series
Collection:
218 Series
Product Function:
Invisible Hinges
Product Size:
4-5/8"
Product Category:
Door Hinges and Pivots
Product Substrate:
Zinc and Steel
Department:
Door Hardware

SOSS 218US26D – Frequently Asked Questions

1) Will the SOSS 218 invisible hinge work on a 1-3/4 inch thick door?
Yes, and 1-3/4 inches is the floor. The 218 is a full size 4-5/8 inch invisible hinge built for wood or metal doors 1-3/4 to 2 inches thick. Below 1-3/4 inches it does not belong on the opening, because the hinge body has to bury inside the door edge and the jamb; a thinner leaf calls for a shorter SOSS invisible hinge sized for that thickness.
2) Is the SOSS 218 hinge approved for a fire rated door?
It is UL labeled at 20 minutes. The 218 carries a 20 Minute UL Fire rating and is listed for hollow metal, sheet metal, tin clad, steel composite and wood core swinging fire doors and frames. That 20 minute label is the limit of what it covers, so an opening whose assembly has to hold a longer rating needs hinges carrying that longer label instead.
3) Can I run wiring through a SOSS 218 invisible hinge for an electrified lock?
No. The 218 is a straight mechanical hinge with no power transfer and no electronic version, so there is no wire path through it. Power to the leaf has to come from a separate device: an electric power transfer, a concealed door loop, or a surface door cord, specified alongside the invisible hinges rather than in place of one of them.
4) Should I use an invisible hinge or a standard butt hinge on a commercial fire door?
Go invisible when nothing may show on the closed door. The 218 mortises fully into the door edge and jamb, so with the door shut there is no knuckle or barrel on the face of the opening, and it still holds a 20 Minute UL Fire label on wood core or hollow metal fire doors 1-3/4 to 2 inches thick. The trade-off is prep: a butt hinge sits in a shallow surface mortise and can be swapped with a chisel and a screw gun, while the 218 needs a routed pocket cut in both the leaf and the frame. On retrofit work with no ability to rout, the butt hinge is the practical choice.
5) Does a door on SOSS 218 hinges swing a full 180 degrees?
Full 180 degrees, yes. The 218 is a single action hinge, so the leaf swings one direction only and travels the full 180 on that side. A door that has to swing both ways is not a job for this hinge; that calls for a double acting hinge or a center pivot.
6) Do SOSS 218 hinges come with screws, or do I supply my own?
Both wood and machine screws ship with the hinge, so the same box covers a wood door and a hollow metal door or frame without a second trip to the counter. What is not included is the pocket. The 218 has to be routed into the edge of the leaf and into the jamb, so plan on the router and template setup as part of the install.
7) Do the mortises for a SOSS 218 hinge have to be chiseled square at the corners?
No, the 218 has radius corners. The pocket a router leaves matches the hinge as cut, so there is no squaring up with a chisel at each corner. Square corner butt hinges are the ones that force that step.
8) Is the SOSS 218 sold as a single hinge or as a pair?
Single. Each 218 is packed one per box as one hinge, so quantity is counted per hinge position, not per door and not per pair. A leaf taking four hinges is a quantity of four.
9) What finishes does the SOSS 218 invisible hinge come in for matching hardware across a building?
Eleven: unplated (UNP), 605 bright brass, 606 satin brass, 609 antique brass, 613L oil rubbed bronze lacquered, 618 bright nickel, 619 satin nickel, 622 matte black, 625 bright chrome, 626 satin chrome and white. Worth remembering that the hinge is concealed with the door shut, so the finish reads only on the open edge. For a fleet of openings that usually makes standardizing on one code, 626 or 619 in most commercial buildings, a stocking decision rather than an appearance one.
10) Will a concealed hinge hold up on a high traffic commercial door?
The 218 is built for it: heavy duty, commercial grade, with zinc and steel construction and nylon links in the linkage carrying the load through the swing. It is the size SOSS puts on full size entry doors in offices, schools, healthcare buildings, retail, industrial space, multi-tenant residential and government facilities, on both wood and metal leaves.
11) What is the SOSS part number for the 218 invisible hinge in satin chrome?
218US26D is the 626 satin chrome version. The model itself is the 218, a 4-5/8 inch full size invisible hinge, and the size is what separates it from the shorter models in the SOSS invisible hinge range.
How fast can I get the SOSS 218US26D delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the SOSS 218US26D come with a warranty?
Absolutely. The SOSS 218US26D is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the SOSS 218US26D?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the SOSS 218US26D from ZenSupply?
ZenSupply makes it easy to get the commercial door hardware you need—fast shipping, expert support, and rewards on every order. Our team is always ready to help you choose the right product for your project.

Product Reviews

  • 5
    Great Price & Quality

    Posted by Ashley Feldman on Jul 21st 2025

    Such quick shipping! Most affordable for a concealed hinge!

!