Written and maintained by CASRAI Editorial Board
Last updated
ASTM D2488 is the standard practice for describing and identifying soils for engineering purposes using non-laboratory, visual-manual procedures. It can optionally assign the same group symbols and names as ASTM D2487, but for precise classification D2488 itself says D2487 must be used. Its identification is limited to soil particles smaller than 3 in. (75 mm).
Definition and scope
The current designation on the ASTM store is D2488-26, titled “Standard Practice for Description and Identification of Soils for Engineering Purposes (Visual-Manual Procedures)”; the store page shows it as last updated 29 April 2026 (checked 29 October 2026). Section 1.1 states that the practice “covers procedures for the description of soils for engineering purposes through non-laboratory based methods.”
Section 1.2 adds a procedure for identifying soils, at the option of the user, based on the classification system described in Test Method D2487. Three points follow directly from the scope text:
- Section 1.2.1: for precise classification, “the procedures outlined in Test Method D2487 shall be used.”
- Section 1.2.2: assignment of a group symbol and group name is “limited to soil particles smaller than 3 in. (75 mm).”
- Section 1.2.3: “It shall be clearly stated in reporting, the soil identification is based on visual-manual procedures.”
The title has changed between editions. The 2000 edition (D2488-00) was titled “Standard Practice for Description and Identification of Soils (Visual-Manual Procedure)”, so reports should cite the edition they actually used. ASTM lists the standard under ICS 93.020 and Subcommittee D18.07 (Book of Standards Volume 04.08).
How it is used in practice
Because it relies on visual examination and manual tests rather than laboratory apparatus, D2488 is a practice for describing soil where it is found or received. A published summary of the standard from Geocomp describes use in the field, the office and the laboratory, and notes that the practice supplements D2487 and uses the same names and symbols. The scope requires that reporting state the identification is based on visual-manual procedures, which keeps readers from mistaking a description for a laboratory classification.
Because the method rests on visual examination and manual tests, the output is a documented description made by a person, not an instrument measurement; where a number is needed, a laboratory test applies.
D2488 versus D2487: which document answers which question
The comparison below is limited to what the D2488 scope text itself says.
| Question | What the D2488 scope says | Section |
|---|---|---|
| Describe a soil without laboratory methods | D2488 covers procedures for description of soils through non-laboratory based methods | 1.1 (current edition) |
| Assign a group symbol and name by eye and hand | Optional procedure in D2488, based on the D2487 classification system | 1.2 (current edition) |
| Obtain a precise classification | Use Test Method D2487 | 1.2.1 (current edition) |
| Identify a soil containing particles larger than 75 mm | Group symbol and name assignment is limited to particles smaller than 3 in. (75 mm) | 1.2.2 (current edition) |
| Identify a manufactured or non-natural material | Identification is limited to naturally occurring soils; the 2000 edition notes the practice may describe materials such as shale and crushed rock | 1.2.3 and Note 1 (2000 edition) |
Where it matters for labs, clinics and supply decisions
For a materials-testing or geotechnical laboratory, D2488 sits at the start of the sample workflow: it records what the soil looks like before test specimens are prepared. Where a result needs numbers, the lab-test standards take over. Two sibling CASRAI guides cover those tests: ASTM D4318 for liquid limit, plastic limit and plasticity index and ASTM D6913 for sieve analysis of soils. Documenting which method produced each result, whether visual-manual or laboratory, is the same discipline a standard operating procedure is meant to enforce. For background on the discipline that uses these descriptions, see what soil science is.
Reporting checklist drawn from the scope text
- State that the soil identification is based on visual-manual procedures (section 1.2.3, current edition).
- Cite the edition used, because the title differs between D2488-00 and D2488-26.
- Confirm the material is a naturally occurring soil (section 1.2.3, 2000 edition).
- Confirm that the symbol and name apply only to particles smaller than 75 mm (section 1.2.2).
- Use D2487 where precise classification is required (section 1.2.1).
Common misunderstandings
- It is not a laboratory classification. The practice describes soils by non-laboratory methods; precise classification belongs to D2487.
- It does not cover coarse material. Group symbols and names are limited to particles smaller than 75 mm.
- It is not for made materials. Identification is limited to naturally occurring soils.
- It is not a measurement. Results come from visual and manual examination, so use a laboratory test where a numeric result is required.
Sources
- ASTM International, D2488-26 store page (scope and abstract), checked 29 October 2026.
- ASTM International, D2488-00 historical edition page, checked 29 October 2026.
- Geocomp, test description for the visual-manual practice, checked 29 October 2026.
