NGP 321 Thermal Bridge Thresho...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$34.85
NGP 321 Thermal Bridge Threshold, Includes Spline

NGP 321 Thermal Bridge Threshold with Spline - 2" x 1/2" Aluminum Alloy Construction

(No reviews yet) Write a Review

Model: 321-36
Selected Finish is

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

$34.85
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

NGP 321 Thermal Bridge Threshold with Spline - 2" x 1/2" Aluminum Alloy Construction

Professional Thermal Break Door Threshold Solution

The NGP 321 Thermal Bridge Threshold delivers professional-grade thermal break performance with precision-engineered aluminum alloy 6063, T5 temper construction. Measuring 2" wide x 1/2" tall with a fluted top design, this threshold provides ADA compliant installation when the non-beveled edge is flush with flooring or where no greater than 1/4" vertical rise occurs. The included spline and mill finish construction ensure reliable thermal barrier performance for commercial door applications.

Professional Features & Benefits

  • Precise Dimensions: 2" wide x 1/2" tall profile designed for standard door applications with optimal thermal break performance.
  • Premium Construction: Aluminum alloy 6063, T5 temper provides exceptional durability and corrosion resistance for long-term commercial use.
  • ADA Compliant Design: Meets accessibility requirements when installed with non-beveled edge flush with flooring or where no greater than 1/4" vertical rise occurs.
  • Thermal Break Engineering: Specifically designed for thermal break applications to reduce energy transfer and improve building efficiency.
  • Fluted Top Surface: Textured top provides enhanced traction and slip resistance for safe pedestrian traffic.
  • Complete Installation Package: Includes spline and #10 x 1-1/2" FH zinc plated wood screws for immediate installation readiness.
  • Lightweight Construction: At .34 lbs./ft. weight, provides easy handling and installation while maintaining structural integrity.
  • Standard Wall Compatibility: Typical wall thickness .110" accommodates most commercial door frame configurations.

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: Door Shoes
  • 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 thermal bridge thresholds deliver professional-grade reliability with aluminum alloy 6063, T5 temper construction engineered for demanding commercial applications. The precision 2" x 1/2" profile with fluted top design provides both thermal performance and ADA compliance capabilities. Engineered for demanding commercial applications where dependable thermal break performance and accessibility compliance are essential.

Manufacturer Resources

NGP Threshold Catalog

Product Specs

Product Group:
Door Trim and Accessories
Product Subgroup:
Door Thresholds
Product Type:
Thresholds - Saddle
Subcategory:
Thresholds
Commercial/Residential:
Commercial
Product Category:
Door Trim and Accessories
Department:
Door Hardware

NGP 321-36 – Frequently Asked Questions

1) Will the NGP 321 threshold meet ADA requirements at my door opening?
The NGP 321 is ADA compliant when the non-beveled edge sits flush with the flooring, or where the vertical rise is no greater than 1/4 inch. The saddle stands 1/2 inch tall overall, so if you set it on top of finished flooring with a full 1/2 inch exposed on the non-beveled side, you are over the 1/4 inch limit and out of compliance. On an accessible opening, plan the floor height so the flat edge comes up flush.
2) Does the NGP 321 come with fasteners, or do I need to order screws separately?
Screws are in the box. Each piece ships with the spline and #10 x 1-1/2 inch flat head zinc plated wood screws. Note the screw type: those are wood screws, so they land in a wood subfloor or wood sill. Over concrete you will need your own anchors and machine screws, which are not included.
3) Should I use a thermal break threshold or a plain saddle threshold on an exterior door?
Use a thermal break saddle like the NGP 321 on any opening where conditioned space meets outside air. The spline interrupts the aluminum so the threshold is not conducting cold to the interior side, which is what causes condensation at the sill in heating climates. On an interior opening, a floor transition, or a closet, the break buys you nothing and a plain flat saddle is the simpler part: the Pemko 272 Series is a flat 1/4 inch x 6 inch aluminum saddle for that job. If the opening is a fire rated door assembly, look at a rated saddle instead, such as the Cal-Royal CR3700 Series with its 3-hour positive pressure fire rating.
4) What is the closest equivalent to the NGP 321 threshold if the opening needs a fire rating?
The NGP 321 is a 2 inch wide by 1/2 inch tall thermal bridge saddle threshold in aluminum alloy 6063, T5 temper, and its published strengths are the thermal break and ADA compliance when the non-beveled edge sits flush with the flooring or the vertical rise is no greater than 1/4 inch. For a fire-rated opening, the Cal-Royal CR3700 Series is a saddle threshold carrying a 3-hour positive pressure fire rating, and the Cal-Royal CR2000 Series is a saddle threshold described as both fire rated and ADA compliant. A locksmith or institutional buyer working a rated door assembly should specify from those two series rather than substituting a thermal break saddle.
5) The NGP 321 is only 2 inches wide. What saddle threshold covers a wider sill?
The NGP 321 profile is 2 inches wide by 1/2 inch tall with a fluted top, which suits a narrow sill where a thermal break is wanted. Where the sill is wider and needs to be bridged, the Pemko 272 Series is a flat saddle threshold at 1/4 inch by 6 inches in heavy-duty aluminum, giving six inches of bearing surface at a low flat height. A contractor measuring an existing sill cut should confirm the width of the opening before choosing between the 2 inch and 6 inch profiles.
6) What lengths does the NGP 321 threshold come in?
Four cut lengths: 36, 48, 72, and 84 inches, and each one is offered in both mill aluminum and dark bronze. A 36 inch piece covers a standard single door opening, 72 and 84 inch pieces are for pairs or for a frame you intend to cut down on site. Aluminum 6063-T5 cuts cleanly with a carbide blade, so ordering long and trimming to the frame is normal practice.
7) What is the spline on the NGP 321 threshold for?
The spline is the insert that fills the groove running the length of the 321, and it is what makes this a thermal bridge threshold: it separates the interior side of the aluminum from the exterior side so heat does not conduct straight across the metal. On a plain saddle with no break, the aluminum carries cold right through to the inside face and sweats in winter. The 321 ships with the spline included, so nothing extra is required to get the break.
8) I am standardizing thresholds across a property. Can I get the NGP 321 to match bronze door hardware?
Dark bronze is a stock finish on the 321, in all four lengths (36, 48, 72 and 84 inches), so you can run the same profile across every exterior opening and still match bronze frames and hardware. Mill aluminum is the other choice for clear anodized or aluminum storefront openings. Ordering one profile in two finishes keeps the spec and the install detail identical building-wide.
9) Is the Pemko 272 a direct substitute for the NGP 321 thermal bridge threshold?
They are both aluminum saddle thresholds and both are described as ADA compliant, but they are different parts. The NGP 321 is a 2 inch by 1/2 inch thermal bridge profile supplied with a spline, engineered to interrupt energy transfer through the threshold. The Pemko 272 Series is a flat saddle at 1/4 inch by 6 inches in heavy-duty aluminum. On a job where the specification calls for a thermal break, the 272 is not the same item; where the requirement is simply a flat aluminum saddle across a wide sill, it is the broader profile.
10) For standardizing thresholds across a facility with a mix of rated and non-rated exterior doors, how do the NGP 321 and the Cal-Royal CR2000 divide up?
The NGP 321 is the thermal break choice on exterior openings, a 2 inch by 1/2 inch aluminum alloy 6063, T5 temper saddle with a fluted top for traction, offered in mill aluminum and dark bronze in 36, 48, 72 and 84 inch lengths, which lets one finish run across an elevation. The Cal-Royal CR2000 Series is a saddle threshold described as fire rated and ADA compliant, which is the series to carry on the rated openings in the same facility. An MRO or institutional buyer can standardize on the 321 for thermal exterior doors and the CR2000 where the door assembly is rated.
11) Will the NGP 321 threshold hold up to heavy foot traffic in a commercial building?
It is built as a commercial part: aluminum alloy 6063 in T5 temper, with a fluted top that gives traction underfoot rather than a smooth face that gets slick when wet. Typical wall thickness in the extrusion is .110 inch. That is the profile NGP puts into offices, schools, hospitals, retail and municipal buildings. Mill aluminum is the bare extrusion finish; dark bronze is the option when it has to match bronze frames or hardware already in the building.
12) What is the difference between the Cal-Royal CR2000 and CR3700 when the NGP 321 will not work on a rated door?
Both are Cal-Royal saddle threshold series. The CR2000 Series is described as fire rated with an ADA compliant design. The CR3700 Series carries a 3-hour positive pressure fire rating. Where the drawing calls out a positive pressure assembly or a 3-hour rating specifically, the CR3700 is the series that states it; where the requirement is a fire-rated saddle with accessibility compliance, the CR2000 covers it.
How fast can I get the NGP 321-36 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 321-36 come with a warranty?
Absolutely. The NGP 321-36 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 321-36?
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 321-36 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.
!