Commercial Door Closers
for Hollow Metal and Wood Doors

Hollow Metal Doors: The Commercial Standard

Hollow metal doors, steel faces over an internal core in a steel frame, are the default for corridors, stairs, mechanical rooms, back-of-house and many exterior openings. They are durable and often fire rated, but they have one installation rule that matters for closers: the closer must be fastened into reinforcement, not just into the thin steel face.

Reinforcement and fasteners

• Door: commercial hollow metal doors are usually ordered with a closer reinforcement in the top of the door. Confirm it is there before ordering the closer.
• Frame: parallel arm and top-jamb installations fasten into the frame head or soffit, which also needs reinforcement.
• No reinforcement? Use the fastening method recommended by the door manufacturer, such as through-bolts, or add a reinforcement. Screws in thin sheet steel alone will pull out over time.
• Fire-rated doors: do not field-modify a labeled door beyond what its listing allows; use the prepared reinforcement.

Wood Doors

Solid-core wood doors hold closer screws well. Fire-rated wood doors with mineral cores are often installed with through-bolts so the fasteners do not loosen in the core; follow the door manufacturer's instructions. Hollow-core residential doors are not suitable for a commercial closer. The DRIWON DN-9500 and DN-8220 are UL listed for rated wood or metal door assemblies.

Choosing Between the DN-9500 and the DN-8220

Both are Grade 1 and adjustable 1–6. Choose the cast iron DN-9500 for heavy-gauge steel doors, stair doors, exterior doors and high-abuse areas. Choose the aluminum DN-8220, supplied with a parallel arm bracket, for interior office, retail and healthcare doors with moderate traffic.

Under the 2010 ADA Standards for Accessible Design (section 404), interior hinged doors must open with no more than 5 lbf, and a closer must be adjusted so the door takes at least 5 seconds to swing from 90° to 12° from the latch. Fire doors are the exception on opening force: the authority having jurisdiction sets the minimum. Always check local code and your AHJ.

More on installation: installation and adjustment guide, mounting types and stairwell door closers.

DRIWON DN-9500 Specifications

Need the lighter-duty option for interior doors? See the DRIWON DN-8220 Grade 1 door closer. Full details on the DN-9500 product page.