Material selection
ABC MAG Spec vs Class II vs Non-Spec
Three crushed base-course products that look nearly identical in the truck but aren’t interchangeable on a plan sheet. The material is similar; the spec is what changes. Here is how to pick the right one for your project.
TL;DR
- MAG Spec — Phoenix municipal public works (City, County, sidewalks, curb & gutter).
- Class II — ADOT highways and state-route projects, plus commercial jobs that spec it.
- Non-Spec — Residential driveways, building pads, fill — anywhere no inspector is checking the spec.
- If your plan sheet calls out a spec, order the spec material. If it doesn’t, Non-Spec saves you money.
ABC MAG Spec
Phoenix public works standard
Spec
MAG Standard Specifications, Section 702 (Aggregate Base Course)
Grading
Tightly graded — passes MAG sieve curve
Fines
Controlled — 7 to 12 percent passing #200
Plasticity
PI ≤ 5 (low plasticity)
Cost
Highest of the three
What it is: Aggregate base course graded and screened to meet the Maricopa Association of Governments (MAG) standard. MAG is the spec that City of Phoenix, Maricopa County, and most municipal jurisdictions in Metro Phoenix call out on plan sheets. The gradation curve, fines content, and plasticity index are all controlled and verifiable by quarry test reports.
Why use it: Public works projects, sidewalks, curb-and-gutter, and most municipal road bases require MAG-spec ABC by ordinance. Engineers and inspectors specifically check for it. Substituting Non-Spec on a job that called for MAG is the kind of thing that gets a project red-tagged.
Avoid for: Residential driveways and casual fill — you're paying for documentation and quarry testing you don't need.
Common uses
- City of Phoenix road base (asphalt subbase)
- Maricopa County public works
- Sidewalks, curb, gutter base
- Municipal building pads
- Pipe trench backfill (MAG 601)
- Any plan sheet calling out MAG 702
ABC Class II
ADOT standard — state highway base
Spec
ADOT Standard Specifications, Section 303 (Aggregate Base Class 2)
Grading
ADOT Class 2 sieve curve — slightly different from MAG
Fines
Up to 12 percent passing #200
Plasticity
PI ≤ 5
Cost
Comparable to MAG, sometimes lower
What it is: Aggregate base course meeting Arizona Department of Transportation (ADOT) Class 2 specification. Same general material as MAG — crushed and graded with controlled fines — but the gradation curve and quality control documentation are written to ADOT's standard rather than MAG's. Sometimes labeled "Class 2 ABC" or "Type II base" on plan sheets.
Why use it: Required on ADOT highway projects, state-route work, and certain commercial jobs where the engineer specs Class 2. Some municipalities accept either MAG or Class 2 as equivalents — the plan sheet will say. If your project sheet says "Class 2" or "Type II," this is the material.
Avoid for: Residential work that doesn't reference the spec — you don't need the documentation overhead.
Common uses
- ADOT highway base layers
- State route shoulder material
- Commercial pads where engineer specs Class 2
- Some municipal work (check plan sheet)
- Caltrans Class 2 substitute jobs
- Anywhere "Class 2" or "Type II" appears on plans
ABC Non-Spec
Residential and uncontrolled fill
Spec
No published specification — quarry-graded base
Grading
Crushed and graded but not certified to MAG or Class 2
Fines
Variable — typically similar to spec products
Plasticity
Not certified
Cost
Lowest — no test-report overhead
What it is: Aggregate base course produced by the same crushing and grading process as MAG and Class 2, but without the test reports and gradation certification. The physical material is often nearly identical — same quarries run all three off the same crusher line — but no documentation backs it up. It's the right product when nobody is going to inspect it against a spec.
Why use it: Residential driveways, building pads with no engineer, retaining wall backfill, RV pads, sport courts, and general structural fill compact and perform well on Non-Spec ABC. You get the same compaction behavior at a lower cost because you're not paying for the testing program.
Avoid for: Any project where a plan sheet, building inspector, or engineer references MAG, Class 2, Type II, or any specific gradation. If it's going to be inspected against a spec, order the spec material.
Common uses
- Residential driveways
- Casual building pads (no engineer of record)
- Retaining wall backfill
- RV and trailer pads
- Sport court base (without spec callout)
- General structural fill
- Pavers / artificial turf base on residential
Why they look identical in the pile
All three are produced from the same crushed limestone, granite, or basalt — usually run off the same crusher line at the quarry. The visible material is gray-brown crushed gravel mixed with rock dust (the “fines”). To the eye, you cannot tell MAG, Class 2, and Non-Spec apart.
The difference lives in the test reports: which sieve curve was hit, what percentage passed the #200 sieve, what the plasticity index measured. Spec products travel with that documentation; Non-Spec doesn’t. That’s the entire pricing delta.
How to pick — fast version
- Open your plan sheet, spec book, or engineer’s notes. Search for “MAG”, “Class 2”, “Class II”, or “Type II”.
- If you find MAG 702 or any MAG callout → order ABC MAG Spec.
- If you find Class 2, Class II, or Type II → order ABC Class II.
- If there’s no plan sheet, no engineer, and no inspector — it’s residential or general fill → ABC Non-Spec is the right call and saves you money.
- Not sure? Call dispatch at (602) 730-0077 with the project type and we’ll route the right spec.
Have the plan sheet handy?
Tell us the spec callout and the tonnage — we’ll route it from the closest MAG- or Class-2-certified quarry.
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