Zero 643A 3" X 1" Carpet Divider Threshold
Zero thresholds are designed to stand up to the demands of heavy traffic openings and those with extreme temperature differentials. The heavy-gauge material allows you to drill and screw our thresholds directly into concrete without the difficulties common when using lighter commercial materials, such as buckling under heavy loads or loose screws.
- Carpet divider thresholds
- Finish: Mill Finish Aluminum
- Length: 50"
- Width: 3"
- Height: 1"
- Thickness: .250"
- Fire Rated
- BHMA Certified
- ANSI: J33300, J33340
Manufacturer Resources
zero thresholds 643 data sheet
Product Specs
- Product Group:
- Door Trim and Accessories
- Product Subgroup:
- Door Thresholds
- Product Type:
- Threshold
- ADA Accessible:
- No
- Commercial/Residential:
- Commercial
- Product Finish:
- Aluminum Mill
- Performance Rating:
- Fire Rated-UL10c
- Product Height:
- 1"
- Product Width:
- 3"
- Department:
- Door Hardware
Zero International 643A 36 – Frequently Asked Questions
1) Is the Zero 643A carpet divider threshold ADA compliant for an accessible opening?
No. The 643A is a 1 inch high carpet divider, and it is not ADA accessible. ADA-compliant openings need a much lower profile with beveled edges. If your opening is on an accessible route, use a low-profile ADA threshold instead and save the 643A for transitions that don't fall under that requirement.
2) Can the Zero 643A be used at a fire rated door opening?
Yes. The 643A carpet divider threshold is fire rated and carries a UL10C performance rating, so it can go under a fire rated opening. It is also BHMA certified to ANSI J33300 and J33340.
3) What size is the Zero 643A carpet divider and what length does it come in?
The 643A profile is 3 inches wide by 1 inch high, with .250 inch thick aluminum stock. It's stocked in a 36 inch length, which covers a standard 3-0 single door opening. For a wider opening or a pair of doors you'd need to run two pieces or cut from a longer stock length.
4) Is the Pemko 61 interlocking J hook a substitute for the Zero 643A carpet divider threshold?
No. The Zero 643A is a finished carpet divider threshold in mill finish aluminum, 3 inches wide by 1 inch high, that sits in the opening as the transition itself. The Pemko 61 is an interlocking J hook threshold accessory in steel construction, 36 inches long - it is a companion piece that interlocks with a threshold rather than a standalone divider. If you need the transition member at the doorway, the 643A is the part; the 61 does not replace it.
5) I need a fire rated threshold for a commercial opening - does the Zero 643A qualify, or do I need a different part?
The Zero 643A is fire rated to UL10c and BHMA certified, tested to ANSI J33300 and J33340, and is specified for commercial use, so it can go into a rated opening. The Pemko 61 is a steel interlocking J hook threshold accessory rather than a rated threshold in its own right, so it is not the item to spec when the drawing calls for the rated threshold. One caution on the 643A: it is not ADA accessible, so if the opening has to meet accessible route requirements you need a low profile ADA threshold instead.
6) Can I screw the Zero 643A straight into a concrete slab?
That's what the heavy-gauge material is for. At .250 inch thick aluminum, the 643A can be drilled and screwed directly into concrete without the buckling under load or screws working loose that you get with lighter commercial stock. Anchors are not supplied, so pick fasteners to suit the slab.
7) What is a carpet divider threshold actually for, and how is it different from a saddle threshold?
A carpet divider handles the transition where carpet meets another flooring material at a doorway, capping the carpet edge so it can't fray or lift underfoot. A saddle or entrance threshold is aimed at weathersealing and taking a door bottom sweep or seal. The 643A is the divider type, 3 inches wide by 1 inch high in .250 inch aluminum, so specify it where you're solving a flooring transition rather than a weather seal.
8) What finish does the Zero 643A come in, and can it be painted or anodized on site?
It ships in mill finish aluminum, which is the raw untreated aluminum surface. That's the standard for thresholds hidden under a door, but if the transition is exposed in a lobby or corridor you may want to plan for a finished divider instead, since mill finish is the only option offered on the 643A.
9) Is the Zero 643A meant for commercial buildings or will it work in an apartment or house?
It's a commercial-duty part. Zero built the 643A for heavy traffic openings and openings with big temperature swings between the two sides, which is why the stock is so heavy. Nothing stops you putting it in a residential unit, but you're paying for durability aimed at schools, hospitals, and multi-family corridors.
10) Do I need any accessory to hold the carpet edge down at the Zero 643A?
The 643A is a one-piece aluminum divider and does not use a separate hook strip. If your detail calls for an interlocking edge instead, Pemko offers a 61 Series interlocking J hook threshold accessory in 36 inch steel that serves that role. Pick one approach or the other, don't mix them at the same opening.
How fast can I get the Zero International 643A 36 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the
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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 Zero International 643A 36 come with a warranty?
Absolutely. The Zero International 643A 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 Zero International 643A 36?
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