NGP 520 Automatic Door Bottom ...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$158.00
$142.80
NGP NGP 520 Automatic Door Bottom with Neoprene Seal, Heavy Duty Surface NGP-520

NGP 520 Automatic Door Bottom with Neoprene Seal - Heavy Duty Surface Mount

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Model: 520NA-36
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$158.00
$142.80
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NGP 520 Automatic Door Bottom with Neoprene Seal - Heavy Duty Surface Mount

Professional Automatic Door Sealing Solution

The NGP 520 Automatic Door Bottom delivers professional-grade door sealing with BHMA certified performance to ANSI/BHMA A156.22 standards. Featuring aluminum alloy 6063 T5 temper construction with synthetic rubber polymer blend seal combining Chloroprene and EPDM materials, this heavy-duty surface mount unit provides reliable sealing across temperature ranges from -20 F to 200 F. Available in lengths from 11" minimum to 60" maximum with 7/8" maximum drop capability for versatile door applications.

Professional Features & Benefits

  • BHMA Grade 1 Certification: Certified to ANSI/BHMA A156.22 with 1,000,000 cycle testing for exceptional durability in high-traffic commercial applications.
  • Temperature Performance: BHMA certified performance testing for heat and cold with operational range from -20 F to 200 F for reliable year-round operation.
  • Heavy-Duty Construction: Aluminum alloy 6063 T5 temper housing provides superior strength and corrosion resistance for long-term commercial use.
  • Advanced Seal Technology: Synthetic rubber polymer blend combining Chloroprene and EPDM offers excellent abrasion resistance, tensile strength, and memory retention.
  • Weather Resistance: Flame resistant and moisture resistant materials with good resistance to ozone, sunlight, and aging for outdoor and demanding environments.
  • Flexible Sizing Options: Available in lengths from 11" to 60" with field cutting capability for 36" and longer units (up to 4" reduction) for custom fit applications.
  • Maximum Sealing Performance: 7/8" maximum drop with surface mount design on push side of door, recommended for use with threshold for optimal sealing.
  • Complete Installation Package: End caps furnished standard with options for half mortise applications and nylon brush for carpet applications without thresholds.

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
  • Retail Establishments
  • 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 aluminum alloy 6063 T5 temper construction and BHMA Grade 1 certification rated for 1,000,000 cycles. Advanced synthetic rubber polymer blend sealing technology provides superior performance across extreme temperature ranges from -20 F to 200 F. Engineered for demanding commercial applications where dependable weathersealing and long-term durability 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 520NA-36 – Frequently Asked Questions

1) Will the NGP 520 automatic door bottom close the gap under my door if the undercut is close to an inch?
The 520 drops a maximum of 7/8 inch, so it seals an undercut up to that. Anything wider than 7/8 inch stays open and you need a different approach, either a threshold to raise the sill or a sweep sized to the gap. NGP recommends using the 520 with a threshold anyway for the best seal, since the drop bar seals against whatever surface is under it.
2) Does the NGP 520 mount on the surface of the door or does it have to be mortised in?
Surface mount, and it goes on the push side of the door. No routing of the door bottom is required, which is why it works on existing doors that were never prepped for a seal. A half mortise option is offered if you want the housing partially let into the door instead.
3) Is the NGP 520 rated for a high traffic commercial entrance or is it a light duty seal?
It is BHMA certified to ANSI/BHMA A156.22 at Grade 1, tested to 1,000,000 cycles. That is the durability tier a facility buyer wants on a door that swings all day, and it is why the 520 gets specified on office, school, healthcare and government openings rather than residential ones. The housing is 6063 T5 aluminum alloy.
4) I have carpet under the door and no threshold. Will the NGP 520 still seal?
There is a nylon brush option for exactly that case, carpet applications without a threshold. The standard neoprene blend seal is meant to bear against a hard surface, and NGP recommends a threshold with it. Over carpet, specify the brush insert instead when you order.
5) What is the closest surface mount automatic door bottom to the NGP 520?
The Pemko SA Series is the direct counterpart. The SA3-36 is a 36 inch surface mount automatic door bottom, the same mounting style and function as the NGP 520, which is also a surface mount automatic door bottom applied to the push side of the door. The difference is in the seal material: the NGP 520 carries a synthetic rubber polymer blend of Chloroprene and EPDM rated from -20 F to 200 F, while the Pemko SA carries a GREENGUARD Gold certified Eco-V insert. If a project is chasing indoor air quality credits, the Eco-V insert is the one to specify; if the opening sees extreme heat or cold, the NGP 520 seal is the one rated for that span.
6) Is the Pemko 3345PK a replacement for an NGP 520?
No. The 3345PK is a Pemko 345 Series door bottom sweep with a rain drip and PemkoPrene insert; the NGP 520 is an automatic door bottom with a mechanism that drops the seal up to 7/8 inch on closing. Even at a matching 36 inch length, swapping one for the other changes how the door seals, how it clears the floor, and what the undercut has to be. If the existing part retracts when the door opens, replace it with an automatic door bottom such as the NGP 520 or the Pemko SA Series, not with a sweep.
7) Will an NGP 520 automatic door bottom hold up on an exterior door through winter and summer?
The 520 is BHMA performance tested for heat and cold and carries an operating range of -20 F to 200 F. The seal is a synthetic rubber polymer blend of chloroprene and EPDM, which resists ozone, sunlight and aging along with moisture, and the 6063 T5 aluminum housing resists corrosion. That combination is what makes it usable on an exterior opening rather than interior only.
8) What is the difference between the NGP 520 and the Pemko SA Series automatic door bottom?
Both are surface mount automatic door bottoms, so either drops a seal only when the door closes. The 520 uses a chloroprene and EPDM synthetic rubber seal and is BHMA Grade 1 certified to A156.22 at 1,000,000 cycles, in 36, 48 and 60 inch lengths and three finishes. The Pemko SA3-36 is a 36 inch surface mount unit with a GREENGUARD Gold certified Eco-V insert, which is the one to look at if the project is chasing indoor air quality credits. On durability specs the 520 is the one with a published cycle rating.
9) Do I have to order end caps separately for the NGP 520?
End caps come with the unit as standard, so the 520 arrives ready to install. What is not in the box is the threshold, and NGP recommends running one under the door for the seal to bear against.
10) Does the NGP 520 automatic door bottom need handing, and does it matter which way my door swings?
No handing to specify. The 520 is surface applied to the push side of the door, so the only thing to get right is that the actuator plunger lands against the jamb the door closes into. Order by length and finish alone.
11) I need a 48 inch or 60 inch automatic door bottom - what are my options?
The NGP 520 covers lengths from 11 inch minimum to 60 inch maximum and is stocked in 36 inch, 48 inch and 60 inch, in Anodized Aluminum, Gold and Dark Bronze. Units 36 inch and longer can be field cut up to 4 inch for a custom fit. The Pemko SA Series automatic door bottom comparable is the SA3-36, a 36 inch unit. For wide openings, double doors, or anything past a standard 36 inch leaf, the NGP 520 is the part that reaches the full width.
12) Which automatic door bottom should I standardize on for a high traffic commercial facility?
For a facility standard, the NGP 520 is the one carrying a published cycle rating: it is BHMA Grade 1 certified to ANSI/BHMA A156.22 with 1,000,000 cycle testing, in aluminum alloy 6063 T5 temper, and it is a commercial product. That cycle number is what a facility standard is written against for corridor, stairwell and entry doors that swing all day. The Pemko SA Series is the alternate automatic door bottom to evaluate alongside it, and the Pemko 345 Series is a fixed sweep rather than an automatic door bottom, so it is not a like-for-like line item on the same spec.
13) The door has no threshold and opens onto carpet - what do I use?
The NGP 520 is the right family for that opening. It is recommended for use with a threshold for optimal sealing, but it is offered with a nylon brush option specifically for carpet applications without a threshold, and the automatic action lifts the seal clear of the carpet on every swing. A fixed sweep like the Pemko 345 Series, which rides on the floor continuously, is the part to avoid over carpet because it drags with every cycle.
14) What finishes does the NGP 520 automatic door bottom come in, and do they all come in every length?
Three finishes: anodized aluminum, gold and dark bronze. All three are made in 36, 48 and 60 inch lengths, so you can match a whole run of doors in one finish regardless of door width. Anodized aluminum is the usual pick against aluminum storefront, dark bronze against bronze storefront or dark frames.
How fast can I get the NGP 520NA-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 520NA-36 come with a warranty?
Absolutely. The NGP 520NA-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 520NA-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 520NA-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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