12.5mm crushed stone aggregate — commonly sold in the trade as 12mm — for RCC, precast and specified road work, supplied by OM Group across North and South Goa through its own stone-crushing operation.
12.5mm aggregate is the intermediate coarse aggregate size, used where a 20mm nominal size does not suit the member geometry or reinforcement while 10mm would be smaller than the design requires. In Indian trade it is almost always referred to as 12mm; IS 383:2016 lists the nominal size as 12.5mm. OM Group produces 12.5mm aggregate through its own stone-crushing operation and supplies it across North and South Goa to RCC contractors, precast manufacturers, road contractors and builders.
Aggregate is the stone fraction of concrete and accounts for most of a mix by volume. The 4.75mm sieve divides fine aggregate, such as sand, from coarse aggregate. 12.5mm is a coarse aggregate, and it is one of the nominal sizes IS 383:2016 tabulates — alongside 10, 16, 20, 40 and 63mm.
The figure refers to nominal size, not a guarantee that every particle measures 12.5mm. Nominal size describes the sieve the bulk of the material passes, with a defined distribution above and below.
12.5mm exists as a distinct grade for a practical reason. Larger aggregate generally requires less cement paste and tends to be more economical, but it has to suit the member being cast. Where member geometry, reinforcement spacing or cover make a 20mm nominal size unsuitable, moving straight to 10mm can be finer than the design requires. 12.5mm can provide an intermediate option in that situation.
The two designations come from different places. IS 383:2016 sets out nominal coarse aggregate sizes of 10, 12.5, 16, 20, 40 and 63mm — there is no 12mm nominal size in the standard. Suppliers, quotations, site vocabulary and search behaviour almost universally say 12mm.
Three things follow from that, and they matter commercially:
The trade name is a label, not a grading. Two suppliers both describing "12mm" may be screening to different sieve ranges. The name alone does not tell you what you are receiving.
A specification naming 12.5mm is naming the IS 383 nominal size, and the grading envelope attached to that designation is what applies.
Comparison between quotations needs the grading, not the label. If rate differs noticeably between suppliers quoting "12mm," the sieve range is the first thing worth checking.
If your specification requires a particular grading or sieve range, state it with your enquiry and it can be confirmed against the material being supplied.
There is no 12mm nominal size listed in IS 383:2016. The standard tabulates 10, 12.5, 16, 20, 40 and 63mm, and 12.5mm is the nominal designation commonly represented in trade as 12mm.
IS 383:2016 sets grading limits for coarse aggregate by sieve analysis, defining the percentage of material expected to pass each sieve for a given nominal size, with separate limit sets for single-size and graded material. The standard also covers particle shape including flakiness and elongation, cleanliness and freedom from deleterious material, water absorption and specific gravity, and mechanical performance assessed through crushing, impact and abrasion testing. Test methods sit in the IS 2386 series.
Crushing plants generally produce single-size grades, which are blended in proportion at mix design to reach the combined grading a concrete design requires. A 12.5mm product is normally one component of that blend rather than the whole coarse fraction.
The main use. Members where geometry, reinforcement spacing or cover make a 20mm nominal size unsuitable, but where a smaller size than 12.5mm is not required by the design.
Where section geometry allows more than 10mm, and mould fill and finish still matter.
Combined with other sizes in proportion at mix design, where the target combined grading calls for an intermediate fraction.
Crushed aggregate in this size band can be used in specified bituminous and surface-dressing applications. Road specifications are governed by the applicable grading envelope and sieve requirements, so the project clause should be checked against the material being supplied.
12.5mm can be used as an intermediate coarse-aggregate fraction in ready-mix and other designed concrete mixes where the approved mix design calls for it. The required grading and proportions should follow the project mix design.
12.5mm may be appropriate in foundations, footings or other concrete members where the approved design requires an intermediate aggregate size between 10mm and 20mm. Selection depends on member geometry, reinforcement, cover and the project specification.
For thin sections and heavily congested reinforcement, 10mm aggregate is generally more appropriate. For conventional slabs, beams and foundations, 20mm aggregate is typically more economical where it fits.
If your engineer or approved mix design has specified the aggregate size, follow that specification. Aggregate size is a design decision and nothing on this page substitutes for it.
Where the size is still being worked out, IS 456:2000 constrains the maximum nominal size of coarse aggregate against the member being cast. The limits generally applied are:
12.5mm may become relevant where the applicable member, reinforcement, cover and project requirements rule out a 20mm nominal size but do not require a smaller size. For example, where the applicable clear spacing limits the maximum nominal aggregate size below 20mm, 12.5mm may become an appropriate intermediate option, subject to the approved structural design and mix requirements.
The general trade-off: 20mm tends to be the most economical where it fits, 10mm is the most accommodating of tight placement, and 12.5mm can sit between the two. Share the member details and application with your enquiry and OM Group can discuss the material requirement and quantities with you.
Based on IS 383:2016 nominal size classifications, IS 456:2000 size limits and general concrete technology practice. Final aggregate selection should follow the project specification and approved mix design.
| 10mm | 12.5mm | 20mm | |
|---|---|---|---|
| Nominal size (IS 383:2016) | 10mm | 12.5mm | 20mm |
| Common trade name | 10mm | 12mm | 20mm |
| Typical role | Useful where tighter placement or smaller sections require it | Intermediate option where 20mm does not suit the member but 10mm is finer than needed | Commonly used for conventional RCC slabs, beams, columns and foundations |
| Reinforcement & placement | Accommodates the tightest bar spacing | Suits members where the applicable limits rule out 20mm | Suits conventional spacing and cover |
| Relative paste demand | Generally highest of the three | Between 10mm and 20mm | Generally lowest of the three |
| Relative economy | Generally least economical per m³ | Intermediate | Most economical where it fits |
| Blending | Commonly blended with 20mm | Used as an intermediate fraction within a blend | Commonly the primary fraction |
| Typical bulk density (industry estimate) | Not published | ≈ 1,580 kg/m³ | ≈ 1,550 kg/m³ |
Pairwise comparisons sit on the sibling pages: 10mm vs 20mm · 20mm vs 40mm.
Aggregate buyers order in different units depending on local trade practice and project documentation. In Goa and Maharashtra, brass and trips are common, while specifications and quotations often run in cubic metres or tonnes.
| Unit | Approximate equivalent |
|---|---|
| 1 brass | 100 cubic feet ≈ 2.83 m³ |
| 1 m³ of 12.5mm aggregate | ≈ 1.58 tonnes |
| 1 brass of 12.5mm aggregate | ≈ 4.5 tonnes |
| 1 tonne of 12.5mm aggregate | ≈ 0.63 m³ |
| 1 cubic foot (CFT) of 12.5mm aggregate | ≈ 45 kg |
If you know your requirement in one unit only, send it in that unit. OM Group can work from brass, cubic metres, tonnes or number of trips.
OM Group operates a vertical shaft impactor (VSI) stone-crushing facility at Banda Wafoli, producing multi-grade crushed stone aggregate from in-house quarried source rock. VSI crushing accelerates stone against stone rather than compressing it, and is generally associated with a more cubical particle shape than compression crushing.
OM Group operates its own transport fleet, including tippers, haulers and transit mixers, with operational bases at Kundaim and Thivim in North Goa and Sancoale in South Goa. Because 12.5mm is usually one fraction within a blended grading rather than a standalone requirement, it is commonly ordered alongside other sizes and can be quoted and dispatched on the same order.
OM Group crushes its own aggregate from its own quarried source rock. Grading and specification questions go to the people producing the material.
12.5mm is rarely the only fraction on a project. It can be quoted and dispatched alongside 10mm, 20mm and other materials on one order.
Delivery runs on OM Group's own fleet from bases in both districts, so scheduling does not depend on a third-party transporter's availability.
Where current data exists for a requirement, OM Group provides it. Where it does not, OM Group says so rather than quoting a figure from a textbook.
Rate depends on quantity, delivery location and schedule, so OM Group quotes against the specific requirement rather than publishing a list rate. Include the following:
| Product | 12.5mm Aggregate — plus any other grades or materials needed |
| Quantity | Volume or weight required |
| Unit | Brass, cubic metres, tonnes or number of trips — whichever you work in |
| Project location | Delivery destination in Goa — determines logistics and affects rate |
| Application | RCC, precast, RMC blending, road work, or other |
| Grading requirement | Any specific sieve range or grading envelope the specification calls for |
| Delivery timeline | One-time supply or a phased schedule |
| Contact | Company name and the person handling procurement |
If your specification names a grading envelope — particularly on road work — send it rather than the size alone. Multiple sizes can go on one enquiry: 12.5mm is commonly ordered with 10mm or 20mm. Phased quantities are quoted and dispatched differently from a single load; flag the schedule upfront.
| Product | 12.5mm Aggregate |
| Also sold as | 12mm Aggregate |
| Category | Coarse aggregate — crushed stone |
| Nominal size | 12.5mm — listed in IS 383:2016 |
| Grading | According to project requirement |
| Production method | VSI crushing |
| Source | In-house quarried rock |
| Applicable standard (general reference) | IS 383:2016 — Coarse and Fine Aggregate for Concrete |
| Size selection (general reference) | IS 456:2000 — maximum nominal size limits by member |
| Test methods (general reference) | IS 2386 series |
| Grading information | On request |
| Documentation | On request, subject to what is current |
| Availability and lead time | Confirmed against project requirement |
State what your engineer or client requires with your enquiry — a sieve range, grading information, or documentation for project records — and OM Group will confirm what is currently available. Where a project requires documentation that is not currently held, OM Group will say so directly rather than supplying a generic substitute.
12.5mm aggregate is crushed stone graded to a nominal size of 12.5mm, used as coarse aggregate in concrete where an intermediate size between 10mm and 20mm is appropriate. It is one of the nominal coarse aggregate sizes listed in IS 383:2016.
In Indian construction trade usage, "12mm" is commonly used as shorthand for the 12.5mm nominal coarse aggregate size listed in IS 383:2016. The actual grading should still be confirmed against the project requirement, because different suppliers may screen the material differently while using the same trade name.
There is no 12mm nominal size listed in IS 383:2016. The standard tabulates 10, 12.5, 16, 20, 40 and 63mm, and 12.5mm is the nominal designation commonly represented in trade as 12mm.
12.5mm aggregate is used in RCC and precast work where an intermediate size suits the member, as a fraction within a blended coarse aggregate grading, and in specified bituminous and surface-dressing applications where the grading envelope calls for this size band.
12.5mm may become relevant where the applicable member, reinforcement, cover and project requirements rule out a 20mm nominal size but do not require a smaller size. The choice should follow the approved structural design and mix requirements.
12.5mm generally carries a lower cement-paste demand than 10mm, so it can be the more economical of the two where the member accommodates it. 10mm is used where reinforcement is heavily congested or sections are thin.
20mm tends to be the most economical where it fits and is commonly used for conventional RCC. 10mm accommodates the tightest placement and suits congested reinforcement and thin sections. 12.5mm can provide an intermediate option where 20mm does not suit the member but 10mm is finer than the design requires.
Yes. 12.5mm is used as coarse aggregate in reinforced concrete, subject to member dimensions, reinforcement spacing, cover and the approved mix design.
Crushed aggregate in this size band can be used in specified bituminous and surface-dressing applications. Road specifications are governed by the applicable grading envelope and sieve requirements, so the project clause should be checked against the material being supplied rather than ordering by trade size alone.
1 brass is 100 cubic feet, approximately 2.83 m³. At a typical bulk density of around 1,580 kg/m³, 1 brass is approximately 4.5 tonnes. This is a typical industry estimate; actual delivered weight can vary with grading, moisture, particle shape, source and compaction.
Approximately 1.58 tonnes, based on a typical industry bulk density of around 1,580 kg/m³. Use confirmed documentation for commercial billing and mix design.
Yes. OM Group can work from brass, cubic metres, tonnes or number of trips. Send the requirement in whichever unit you work in.
OM Group supplies 12.5mm aggregate — commonly sold in the trade as 12mm — across North and South Goa, produced at its own VSI stone-crushing facility at Banda Wafoli and delivered on OM Group transport. Request a quote on this page or contact OM Group directly.
Yes. 12.5mm aggregate is part of OM Group's crushed stone aggregate range, supplied to RCC contractors, precast manufacturers, road contractors and builders across North and South Goa.
Yes. OM Group operates a VSI stone-crushing facility at Banda Wafoli producing multi-grade crushed stone aggregate from in-house quarried source rock.
Yes. OM Group supplies aggregate at project volumes and operates its own tippers and haulers for dispatch. Share the quantity, delivery location and timeline for a bulk quotation.
Rate depends on quantity, delivery location and schedule, so OM Group quotes against the specific requirement rather than publishing a list rate. Share quantity, project location and timeline for current pricing.
Availability is confirmed against the project requirement. Contact OM Group with quantity, location and timeline.
Current grading information and available documentation can be provided on request, confirmed against the material being supplied.
Yes. OM Group operates its own transport fleet with bases at Kundaim, Thivim and Sancoale, delivering across North and South Goa.
Use the Request a Quote form on this page with quantity, unit, project location, application and any grading requirement, or contact OM Group directly by phone or WhatsApp.
Share quantity, project location, application and any grading requirement, and OM Group will confirm current availability and pricing. Brass, cubic metres, tonnes or trips — send it in whichever unit you work in. Multiple sizes can be quoted together.