Made in the USA • Patented • 100% No Breakage Money Back Guarantee
What Is the JAWS® RailFin Screed Chair?
JAWS® RailFin is a stay-in-place concrete screed chair designed to support a 1/4″ (0.25″ / 6 mm) flat rolled metal screed rail (commonly 0.25″ x 2″).
The patented “fins” inside the barrel hug the mounting structure so the chair will not bounce off rebar or rod during concrete placement.
Designed For
- Slab-on-grade construction
- Vapor barrier slabs
- Elevated slabs and metal decks
- Precast and sand-base applications
- Bridge decks and infrastructure projects
- Super flat floors requiring FF/FL compliance
Ideal for use on projects requiring compliance with ACI 302.1R-04, ACI 117 and ASTM E1155. Iowa DOT approved.
Key Specifications
-
Product Number: 08244JAW25
-
Overall Height: 2.75″
-
Supports: 0.25″ x 2″ flat rolled metal rail (1/4″ flat rail screed)
-
Fits Mounting Structures: 3/8″–5/8″ (10–16 mm), 1/2″ ideal
-
Minimum Height (example rail): 4-1/4″ (108 mm) from bottom of chair to finished elevation using 1/4″ x 2-1/2″ flat rail
-
Load Capacity: Holds up to 1,000 lbs
-
Spacing: Every 3–4 ft depending on rail length and sub-grade conditions
-
Coverage: 100 JAWS RailFins per bag (approx. 3,000 sq ft / 278 m²)
-
Material: Impact-resistant medical grade polypropylene
-
Non-conductive / Non-corrosive: Will not corrode in extreme environments
-
Adjustability: Fully adjustable when used with MAKO FinStand and Base Plate 4.5
-
Country of Origin: Made in USA
Compliance, Approvals & Patents
-
Standards: ACI 302.1R-04, ACI 117, ASTM E1155
-
Approvals: Iowa DOT approved (other states pending)
-
Patents: 8,096,182 | 8,544,182 | Patent Pending
How It Works
- Insert mounting structure (rebar, rod, stake, etc.) between 3/8″–5/8″.
- Slide JAWS RailFin onto mounting structure until seated.
- Place the 1/4″ flat rolled rail into the JAWS “teeth” to secure.
- Set chairs approximately every 3–4 feet (adjust based on rail length and sub-grade).
- Pour and strike concrete using hand or mechanical screeds.
JAWS RailFin is designed as a stay-in-place form and remains in the slab after placement.
Rail Recommendation (Stability Tip)
For best stability, we recommend using a T-rail with the JAWS RailFin. The T-rail acts as a backbone for the screed and increases stability. A typical 1/4″ thick T-rail is 1-1/2″ to 2″ tall with a 1″ to 1-1/2″ wide “T” welded on top.
Why Contractors Choose JAWS RailFin
- Designed specifically for 1/4″ flat rail screeds
- JAWS “teeth” hold rail securely yet release easily as you move down the pour line
- Will not bounce off rebar or rod during placement
- Non-conductive and non-corrosive for bridge decks, waterways, and power plant projects
- Fully adjustable support when used with FinStand and Base Plate 4.5
Common Applications
- Bridge decks and infrastructure slabs
- Vapor barrier slabs
- Precast setup and sand-base applications
- Metal decks and elevated slabs
- Industrial and commercial floors
Frequently Asked Questions
What rail does the JAWS RailFin support?
JAWS RailFin is designed to support a 1/4″ (0.25″) flat rolled metal rail (commonly 0.25″ x 2″).
What mounting structures can be used?
Fits mounting structures from 3/8″ to 5/8″ including rebar, threaded rod, stakes, dowels, PVC, or conduit.
How far apart should JAWS RailFins be spaced?
Typically every 3–4 feet depending on rail length, thickness, and sub-grade conditions.
Can JAWS RailFin be left in the slab?
Yes. JAWS RailFin is a stay-in-place form made from medical grade polypropylene and will not corrode.
Does the MAKO Driver work with JAWS RailFin?
No. The MAKO Driver is not designed to work with the JAWS RailFin chairs.
Downloads
