NGP 423N Heavy-Duty Mortise Au...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$145.00
$83.23
NGP 423N Heavy-Duty Mortise Automatic Door Bottom with Neoprene Seal - Mill Aluminum Finish

NGP 423N Heavy-Duty Mortise Automatic Door Bottom with Neoprene Seal - Mill Aluminum Finish

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Model: 423N-36

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

$145.00
$83.23
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NGP Heavy-Duty Mortise Automatic Door Bottom with Neoprene Seal - Mill Aluminum Finish

Professional Automatic Door Bottom Sealing Solution

The NGP Heavy-Duty Mortise Automatic Door Bottom delivers superior sealing performance with BHMA certified construction rated for 1,000,000 cycle testing. Featuring aluminum alloy 6063 T5 temper construction with advanced neoprene seal technology, this automatic door bottom provides reliable moisture and air sealing for commercial applications. Available in lengths from 11" to 48" with mortise dimensions of 15/16" x 1-5/8" and maximum 3/4" drop capability.

Professional Features & Benefits

  • Heavy-Duty Durability: BHMA certified for ANSI/BHMA A156.22 with 1,000,000 cycle test-grade rating for long-term reliability in high-traffic applications.
  • Advanced Seal Technology: Synthetic rubber polymer blend of PVC, Nitrile rubber (NBR), and Chloroprene closed cell elastomeric foam provides superior sealing performance.
  • Temperature Performance: Operates effectively in temperature range from -20 F to 200 F with excellent resistance to ozone, sunlight and aging.
  • Professional Construction: Aluminum alloy 6063 T5 temper with mill aluminum finish provides exceptional durability and corrosion resistance.
  • Flexible Installation: Available 11" to 48" in length with field cutting capability for 36" and longer units (up to 4" reduction).
  • Fire Door Compatible: Fits wood fire door mortise restrictions with precise 15/16" x 1-5/8" mortise requirements.
  • Enhanced Sealing Options: Use with threshold for maximum sealing capability or nylon brush for carpet applications without threshold.
  • Professional Accessories: Anodized aluminum end caps furnished standard with DKB end caps available upon specification.

Technical Specifications

  • Commercial/Residential: Commercial
  • Department: Door Hardware
  • Product Category: Door Trim and Accessories
  • Product Group: Door Trim and Accessories
  • Product Subgroup: Door Bottom Sweeps and Door Shoes
  • Product Type: Automatic Door Bottoms
  • Subcategory: Gaskets & Weatherstripping

Professional Applications

  • Commercial Office Buildings
  • Educational Facilities
  • Healthcare Institutions
  • Fire-Rated Door Applications
  • Industrial and Warehouse Facilities
  • Multi-Tenant Residential Properties
  • Government and Municipal Buildings

Why Choose NGP Quality?

NGP automatic door bottom products deliver professional-grade reliability with BHMA certified construction rated for 1,000,000 life cycles and ANSI/BHMA A156.22 performance testing for heat and cold conditions. The advanced synthetic rubber polymer blend seal technology provides exceptional abrasion resistance, tensile strength and memory for consistent sealing performance. Engineered for demanding commercial applications where dependable environmental sealing and fire door compliance are essential.

Product Specs

Product Group:
Door Trim and Accessories
Product Subgroup:
Door Bottom Sweeps and Door Shoes
Product Type:
Automatic Door Bottoms
Subcategory:
Gaskets & Weatherstripping
Commercial/Residential:
Commercial
Product Category:
Door Trim and Accessories
Department:
Door Hardware

NGP 423N-36 – Frequently Asked Questions

1) What mortise size does the NGP 423N automatic door bottom need cut into the door bottom?
The 423N drops into a 15/16 inch by 1-5/8 inch mortise, and it will drop up to 3/4 inch onto the sill. Those mortise dimensions are what let it go into a wood fire door, where the amount of material you can remove from the bottom rail is restricted. Rout the pocket to that size, not larger, or you lose the fit and the fire door prep.
2) Should I use a mortise automatic door bottom or a surface mounted one?
A mortise unit like the 423N hides inside a pocket routed into the bottom rail of the door, so nothing shows and there is nothing to knock off. It costs you a rout, and on a wood fire door the pocket has to stay within the 15/16 by 1-5/8 inch mortise limit. Surface mount is the retrofit answer when you cannot or will not machine the door: it screws to the face of the door bottom. ZenSupply carries the Pemko SA Series surface mount automatic door bottom in 36 inch for that case. Same job, different install.
3) Do I need a threshold with the NGP 423N, or will it seal on carpet?
Both work, but they are different setups. Run the 423N down to a threshold when you want the tightest air and moisture seal. On carpet with no threshold, use the nylon brush version instead of the neoprene seal, since a solid seal drags and will not close down onto pile. Decide that before you order, because it is the seal insert that changes.
4) Is the NGP 423N automatic door bottom rated for a high traffic commercial opening?
It is BHMA certified to ANSI/BHMA A156.22 with a 1,000,000 cycle test grade rating, and it is a commercial product, not a residential one. That cycle count is the number that matters on a school corridor, a hospital door, or a multi-tenant entry that swings all day. Body is 6063 T5 aluminum in mill finish.
5) Can the NGP 423N go on a wood fire door?
Yes. The 423N is built to fit wood fire door mortise restrictions, using the 15/16 by 1-5/8 inch pocket. That small a mortise is the whole point on a fire rated leaf, where you cannot take a deep cut out of the bottom rail. Confirm the opening's own rating requirements with the door manufacturer's listing before you machine it.
6) Can a door bottom sweep be used instead of the NGP 423N mortise automatic door bottom?
Only if the opening does not need the seal to lift when the door swings. The NGP 423N is an automatic door bottom: the seal drops up to 3/4 inch when the door closes and retracts when it opens, so it clears carpet and floor transitions. The Pemko 345 Series 36 inch door bottom sweep is a fixed sweep with a PemkoPrene insert, so the seal rides at a constant height whenever the door moves. The 345 Series sweep also carries a rain drip, which the 423N does not, making it the choice on an exterior opening where water running down the door face has to be thrown clear. On an interior opening over finished flooring, the retracting seal of the 423N is what keeps the seal off the floor during swing.
7) What is the closest automatic door bottom to the NGP 423N if the door cannot be mortised?
Use the Pemko SA Series surface mount automatic door bottom, SA3-36, in 36 inch. The NGP 423N is a mortise automatic door bottom that requires a 15/16 inch by 1-5/8 inch pocket cut into the door edge, so it is ruled out on a door you cannot machine, on a hollow metal door already filled, or on an existing door being retrofitted in place. The Pemko SA3-36 performs the same job, an automatic drop seal at the bottom of the door, but mounts to the face of the door rather than into it, so no mortise pocket is needed. Both are 36 inch units.
8) Will an automatic door bottom with a neoprene seal hold up on an exterior door in cold or hot weather?
The seal runs from -20 F to 200 F and resists ozone, sunlight, and aging. It is a synthetic rubber polymer blend of PVC, nitrile rubber (NBR), and chloroprene closed cell elastomeric foam, so it takes UV and weather better than a plain foam. Pair it with a threshold on an exterior opening for the full seal.
9) Which length of NGP 423N do I order for a 36 inch door?
Take the 36 inch unit for a standard 36 inch leaf, and the 48 inch for a wider opening. If your leaf falls between sizes, both of those cut down as much as 4 inches in the field. NGP builds this one from 11 inches to 48 inches, so short openings are covered by ordering to size rather than trimming.
10) For a wood fire door, is the mortise NGP 423N or a surface mount automatic door bottom the right choice?
The NGP 423N is built to fit wood fire door mortise restrictions, with a 15/16 inch by 1-5/8 inch mortise and BHMA certification to ANSI/BHMA A156.22 at a 1,000,000 cycle test grade, so it is the unit specified when the pocket can be cut within what the fire door manufacturer permits. Where the fire door label does not allow machining the bottom edge, the Pemko SA Series SA3-36 surface mount automatic door bottom is the alternative form, since it fastens to the door face instead of into the edge. Confirm the drop seal is accepted on the specific door label either way.
11) What is the difference between a PemkoPrene sweep insert and the neoprene seal on the NGP 423N?
The NGP 423N carries a neoprene seal, a synthetic rubber polymer blend of PVC, nitrile rubber and chloroprene closed cell elastomeric foam, rated from -20 F to 200 F with resistance to ozone, sunlight and aging, and it is carried on a retracting mechanism inside a 6063 T5 aluminum housing. The Pemko 345 Series sweep uses a PemkoPrene insert, and the Pemko SA Series SA3-36 uses a GREENGUARD Gold certified Eco-V insert, which is the one to quote when the project has an indoor air quality or low emitting materials requirement on the submittal. All three are the wearing part that meets the floor, so match the insert to the environment before matching the housing.
12) What finish does the NGP 423N come in, and will it match my other door hardware?
Mill aluminum only on the 423N, which is the raw unfinished aluminum look. It is nearly invisible in service anyway, since the housing sits mortised inside the bottom rail of the door with only the seal edge below. The end caps supplied are anodized aluminum.
13) Which automatic door bottom can be cut down on site, the NGP 423N or the Pemko SA3-36?
The NGP 423N can be field cut on units 36 inches and longer, by up to 4 inches, so a 36 inch or 48 inch unit can be trimmed to an odd door width without reordering. The Pemko SA3-36 is supplied as a 36 inch surface mount automatic door bottom. On a job with a mix of nonstandard widths, the field cutting allowance on the 423N is what lets one length cover several openings.
How fast can I get the NGP 423N-36 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 NGP 423N-36 come with a warranty?
Absolutely. The NGP 423N-36 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 NGP 423N-36?
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 NGP 423N-36 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.
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