Neenah Foundry CatalogR-Number Reference & Grates
A reference hub for the Neenah Foundry Construction Castings catalog — including a decoder for the R-number system that municipal and DOT engineers use to spec manhole frames, inlet grates, trench grates, and airport castings nationwide.
The National Reference Standard for Municipal Castings
Neenah Foundry Company (Neenah, Wisconsin; founded 1872) is one of the largest U.S. manufacturers of municipal and construction castings — manhole frames and covers, inlet frames and grates, trench grates, tree grates, airport and heavy-duty castings, bridge drainage, and access covers in gray and ductile iron.
Neenah's Construction Castings catalog (catalog "R")is so widely adopted that engineers spec castings by Neenah R-number even when buying from other foundries. That makes the R-number system the industry's lingua franca — and the reason this page leads with an R-number decoder. Like US Foundry, Neenah is a municipal/DOT castings vendor, distinct from the engineered drainage systems sold by NDS, ACO, and Josam.
The Neenah R-Number System
Every Neenah product carries an R-prefixed catalog number (e.g., R-1878, R-3067). The "R-" is a fixed Neenah designation; the digits cluster by product family, and trailing suffix letters denote the variant.
How to read an R-number
- Base series — the R-number itself (e.g., R-3067 is a combination inlet series). The digit range tells you the product family (see the table below).
- Suffix letter — the variant/configuration. For R-3067: -C (combination inlet without curb box), -L, -V, and -VB, each a different grate/curb-box configuration with a different open area (e.g., R-3067-V ≈ 2.4 sq ft, R-3067-VB ≈ 2.7 sq ft, R-3067-L ≈ 2.1 sq ft).
- Grate Type letters — Neenah grates carry Type designations defining the profile/pattern: Type A (Flat), Type B (Convex), Type C/D (Concave), Type G, Type R, and others.
- Distributor SKUs— resellers re-encode R-numbers (e.g., Ferguson "NR30670004" = Neenah R-3067 variant 0004; "NR18780052" = Neenah R-1878 variant 0052).
R-Number Range → Product Family
| R-Number Range | Product Family |
|---|---|
| R-1404 – R-1799 | Manhole Frames & Lids (covers) |
| R-1800 – R-1999 | Manhole Frames & Lids (covers), continued |
| R-2014 – R-2994 | Inlet Frames & Grates |
| R-3000 – R-3473 | Combination Inlets (catch basin + curb box) |
| R-3475 – R-3499 | Airport Castings |
| R-3501 – R-3808 | Roll & Gutter Inlets |
| R-3900 – R-4018 | Bridge Scuppers / Bridge Drainage |
| R-4028 – R-4976 | Drainage Grates |
| R-5000 – R-8580 | Valves, Gates, Access / Hatch Covers |
Ranges are approximate and aggregated from Neenah catalog data; use them to identify the family, then confirm exact dimensions and load class against the current Neenah Construction Castings catalog.
Common Neenah R-Numbers
18–19 in. manhole frame & lid (Manhole Frames & Lids range).
Cast iron manhole frame (Manhole Frames & Lids range).
Inlet frame & grate, approx. 35-7/16 x 25-3/4 in. (Inlet Frames & Grates range).
Combination inlet series (catch basin + curb box); variants -C / -L / -V / -VB.
Neenah Foundry Product Families
Neenah's Infrastructure Solutions taxonomy, with the R-number ranges that map to each family.
Manhole Frames & Covers
Gray and ductile iron frame-and-cover assemblies with pressure and watertight options. Spec range R-1404 – R-1999.
- Solid, vented & watertight
- Pressure-rated options
- R-1404 – R-1999
Inlet Frames & Grates
Catch basin grates, roll grates, combination inlets with curb box, and bicycle-safe / ADA patterns. Meets AASHTO M360.
- Combination inlets
- Bicycle-safe & ADA
- R-2014 – R-3808
Trench Frames & Grates
Cast iron trench and channel grate systems for linear surface drainage in roadways and industrial sites.
- Linear drainage
- Multiple grate types
- Traffic-rated
Airport Products
Ductile iron, heavy aircraft-load castings engineered for runway, taxiway, and apron drainage. Spec range R-3475 – R-3499.
- Ductile iron
- Aircraft-load rated
- R-3475 – R-3499
Bridge Drainage
Scuppers and bridge deck drains for structural deck drainage. Spec range R-3900 – R-4018.
- Deck scuppers
- Bridge drains
- R-3900 – R-4018
Tree Grates
Decorative cast iron tree grates for streetscape and pedestrian areas with ADA-compliant openings.
- Square & round
- Decorative patterns
- ADA openings
Detectable Warning Products
ADA detectable warning plates (truncated domes) for pedestrian crossings and transit platforms.
- Truncated domes
- ADA compliant
- Cast iron
Access & Hatch Covers
Utility access and hatch covers, plus valves and gates. Spec range R-5000 – R-8580.
- Access & hatch
- Valves & gates
- R-5000 – R-8580
Downspout Boots
Cast iron downspout boots that protect and transition vertical downspouts at grade.
- Cast iron
- Grade transition
- Impact-resistant
AASHTO, H-20 & HS-20 Load Classes
Neenah castings are specified by proof load and highway loading class. Here is how the standards map to real traffic loads.
The proof-load specification for cast iron construction castings. Legacy products are produced to M306; Neenah engineers current products to the modern AASHTO M360 proof-load spec.
The standard highway design loading for traffic-bearing castings — 16,000 lb per wheel (32,000 lb axle). The default rating municipalities require for in-roadway frames, grates, and covers.
A 25% increase over HS-20 for interstate, heavy-truck, and high-traffic crossings, plus airport castings engineered to far higher aircraft wheel loads.
ADA-compliant detectable patterns and bicycle-safe grate openings, plus Buy America domestic melt and pour compliance for federally funded projects.
Related Product Categories & Applications
Neenah R-numbers translate into the everyday product categories we stock and the municipal, roadway, and aviation projects we help drain. Use these links to compare cast iron against other systems or to see how a frame, grate, or inlet specifies for a given job.
By product category
Neenah's inlet frames & grates, manhole frames & covers, and trench grates map directly to these buyer-facing categories, where cast iron is compared against polymer-concrete and plastic alternatives.
- Cast iron drainage grates— the R-4028–R-4976 grate ranges and more
- Catch basins & inlets— combination inlets (R-3000–R-3473) with curb box
- Trench drains— Neenah trench frames & grates for linear runoff
- Detention & conveyance— bridge scuppers & access covers for stormwater systems
Where Neenah castings are used
As the national reference standard, Neenah castings appear on nearly every traffic-bearing surface — from interstates to runways. These project pages cover the most common municipal, roadway, and aviation uses.
- Highways & roadways— inlet frames, roll grates & H-20/HS-25 covers
- Airports— ductile iron aircraft-load airport castings (R-3475–R-3499)
- Parking lots— traffic-rated grates & manhole frames
- Water works— access & hatch covers, valves and gates
Designing a pedestrian streetscape? Neenah's decorative tree grates and detectable warning plates also fit courtyards and plazas. When you need to confirm a class, our load-rating reference explains how AASHTO and H-20/HS-25 map to a Neenah R-number.
Neenah Foundry R-Number FAQ
What is a Neenah R-number?
A Neenah R-number is the catalog number Neenah Foundry assigns to every product in its Construction Castings catalog (e.g., R-1878, R-3067). The "R-" prefix is a fixed Neenah designation; the digits cluster by product family and trailing suffix letters denote the variant. Engineers spec castings by R-number nationwide, even when buying from other foundries.
How do I decode a Neenah R-number?
Read it in three parts: the base R-number identifies the product family by digit range (e.g., R-3000–R-3473 are combination inlets), the suffix letter (-C, -L, -V, -VB) gives the configuration and open area, and a Type letter (A flat, B convex, C/D concave) describes the grate profile. Distributors re-encode these as SKUs like Ferguson NR30670004 (= R-3067 variant 0004).
Which Neenah R-number range covers manhole covers?
Manhole frames and lids (covers) fall in the R-1404 – R-1999 range. Inlet frames and grates run R-2014 – R-2994, combination inlets R-3000 – R-3473, airport castings R-3475 – R-3499, roll & gutter inlets R-3501 – R-3808, bridge drainage R-3900 – R-4018, drainage grates R-4028 – R-4976, and valves/access/hatch covers R-5000 – R-8580.
What is the difference between R-3067-C, -L, -V, and -VB?
They are configuration variants of the R-3067 combination inlet series. -C is a combination inlet without curb box; -L, -V, and -VB are different grate/curb-box configurations with different open areas — roughly R-3067-L ≈ 2.1 sq ft, R-3067-V ≈ 2.4 sq ft, and R-3067-VB ≈ 2.7 sq ft of inlet open area.
Are Neenah castings AASHTO and H-20 rated?
Yes. Neenah construction castings are produced to the AASHTO proof-load standard (legacy M306, current M360), and traffic-bearing products meet H-20 / HS-20 highway loading (16,000 lb per wheel), with HS-25 and aircraft-load airport ratings available. Neenah also offers ADA-compliant and bicycle-safe patterns and Buy America domestic melt and pour.
How do I buy Neenah Foundry grates or covers?
Shop cast iron and ductile iron grates on DrainageConnect, our affiliated store, or send us a Neenah R-number for a wholesale quote. Spec-driven municipal and DOT buyers typically quote by R-number, which is exactly how our quoting process works.
Shop or Quote Neenah Castings
Browse cast iron and ductile iron grates on DrainageConnect, or send us a Neenah R-number and we'll specify and quote the matching casting for your project.