No. 57, No. 67 and No. 8 are aggregate gradation designations, not one particle dimension. ASTM D448 covers size-number designations and size ranges for mechanical sieve analysis.1 A shorthand range such as “1 inch to No. 4” does not mean every piece must fall between those limits. Compare the permitted percentages passing each sieve, then confirm the governing specification and supplier product.
Quick comparison: No. 57, No. 67 and No. 8
| Aggregate designation | Common shorthand from a secondary summary | Metric shorthand |
|---|---|---|
| No. 57 | 1 in to No. 4 sieve | 25.0 to 4.75 mm |
| No. 67 | 3/4 in to No. 4 sieve | 19.0 to 4.75 mm |
| No. 8 | 3/8 in to No. 8 sieve | 9.5 to 2.36 mm |
These shorthand ranges are from US Made Supply’s D448 summary, not a substitute for the full sieve requirements.2 “No. 8 aggregate” is the product gradation; “No. 8 sieve” is a sieve opening. They are not the same kind of number. The summary identifies No. 4 as 4.75 mm, No. 8 as 2.36 mm and No. 16 as 1.18 mm.2
Percent passing explains the actual mix
The FHWA research report below reproduces selected AASHTO M43-05 (ASTM D448) aggregate designations in its Table 4.3 This is a published reference table from that report, not verification of the current contract specification or of your delivered batch. Selected rows for the three products are shown here:
| Sieve | No. 57: % passing | No. 67: % passing | No. 8: % passing |
|---|---|---|---|
| 1.5 in | 100 | Not listed | Not listed |
| 1 in | 95–100 | 100 | Not listed |
| 3/4 in | Not listed | 90–100 | Not listed |
| 1/2 in | 25–60 | Not listed | 100 |
| 3/8 in | Not listed | 20–55 | 85–100 |
| No. 4 | 0–10 | 0–10 | 10–30 |
| No. 8 | 0–5 | 0–5 | 0–10 |
| No. 16 | Not listed | Not listed | 0–5 |
Source: FHWA Table 4.3 “Not listed” preserves a blank cell in the reference; it does not mean zero passing. Notice that No. 57 can include some material smaller than the No. 4 opening, and not every particle must pass the 1-inch sieve. Likewise, No. 8 has a 100%-passing requirement at 1/2 inch, despite the commonly quoted 3/8-inch shorthand. Do not present shorthand endpoints as absolute minimum and maximum particle dimensions.
Other common shorthand designations
| Designation | Secondary summary shorthand | Metric shorthand |
|---|---|---|
| No. 1 | 3 1/2 to 1 1/2 in | 90 to 37.5 mm |
| No. 2 | 2 1/2 to 1 1/2 in | 63 to 37.5 mm |
| No. 3 | 2 to 1 in | 50 to 25.0 mm |
| No. 4 | 1 1/2 to 3/4 in | 37.5 to 19.0 mm |
| No. 5 | 1 to 1/2 in | 25.0 to 12.5 mm |
| No. 6 | 3/4 to 3/8 in | 19.0 to 9.5 mm |
| No. 7 | 1/2 in to No. 4 | 12.5 to 4.75 mm |
| No. 68 | 3/4 in to No. 8 | 19.0 to 2.36 mm |
| No. 78 | 1/2 in to No. 8 | 12.5 to 2.36 mm |
| No. 89 | 3/8 in to No. 16 | 9.5 to 1.18 mm |
| No. 9 | No. 4 to No. 16 | 4.75 to 1.18 mm |
Shorthand reproduced from US Made Supply.2 This table is not the full ASTM classification and does not supply all acceptance limits. The designations are labels, not a numeric ranking of average diameter or a universal list of suitable uses.
Size number, rock type and local product name are different
The FHWA study tested No. 8 aggregates from different sources, including limestone and diabase, illustrating that one gradation designation does not name one rock type.3 Ask separately about the rock, grading, fines and intended specification. Names such as “3/4-inch stone,” “crusher run” and state DOT numbers need their own supplier or governing-specification definition. Similar names are not proof of equivalent products.
ASTM’s public scope covers highways and bridges, and its significance section notes that contract documents may require closer grading limits.1 A size designation alone does not approve a product for your concrete mix, drainage system, pavers, shed or driveway. Use the project’s material specification rather than selecting a number solely from a web chart.
Three checked examples
1. A shorthand range is not a uniform stone size
For a selected 100-lb representative sample, No. 57’s published 25–60% passing the 1/2-inch sieve corresponds to 25–60 lb passing. Its 0–10% passing No. 4 corresponds to 0–10 lb passing.3 These are nested cumulative passing amounts, not independent buckets to add together. One sieve result cannot verify the complete gradation.
2. One sieve can show a mismatch, not a complete pass
If a hypothetical No. 8 sample has 20% passing the No. 8 sieve, that exceeds the reference table’s 0–10% interval by 10 percentage points.3 That is a mismatch with this table, not a substitute for an official acceptance decision under the current project specification. Conversely, 5% passing that sieve would fall within this one interval but would not prove all other requirements are met.
3. Quantity is separate from gradation
A selected 12 × 20-foot rectangle with a selected 6-inch loose layer contains 120 cu ft = 4.444444 loose cu yd. A hypothetical chosen 10% handling reserve gives 132 cu ft = 4.888889 loose cu yd. If the supplier confirms 1.4 US short tons per matching loose yard, mass with that reserve is 6.844444 short tons. The density and reserve are example inputs, not properties implied by No. 57, No. 67 or No. 8. A finished/compacted target needs its own defined conversion.
What to ask the supplier
- Which specification and edition does this exact product meet? Is a recent gradation report available?
- What is the rock type and actual product name? Is it washed, clean or supplied with fines under a defined specification?
- What material does the project require for each layer or use?
- What volume state and moisture basis does the quoted density use? Which ton unit and sales increment apply?
FAQ
Is 3/4-inch stone always No. 67?
No. A trade description does not establish the full permitted percent-passing distribution. Ask for the product specification.
Is No. 8 stone the same as material passing a No. 8 sieve?
No. One is a gradation designation; the other is an individual sieve opening. The reference No. 8 product allows only 0–10% passing the No. 8 sieve.3
Can I identify compliance with a ruler?
A ruler can describe individual pieces, not the full sample’s sieve distribution. The FHWA study used sieve analysis to check its samples against the appropriate requirements.3
Does the size number tell me tons per yard?
No. It does not establish the matching bulk density, moisture condition or loose/installed volume basis. Use a supplier-confirmed factor for the actual material.
Related tools and guides
Gravel quantity calculator | Density reference chart | Yards and US short tons converter | Gravel quantity guide | Regional driveway stone names
Sources
- ASTM International: D448-12(2022) public standard page (scope and significance only; full paid standard not purchased)
- US Made Supply: ASTM D448 summary (secondary shorthand ranges and sieve opening sizes)
- FHWA: Strength Characterization of Open-Graded Aggregates, Chapter 3 (Table 4 percent-passing requirements and tested aggregate sources)