#57 Stone

Number 57 stone starts as quarried granite, traprock, or limestone that gets crushed and run through a sieve process to isolate the ASTM C33 #57 gradation. That standard calls for a blend passing a 1 inch sieve, with the bulk of material retained between 3/8 inch and 3/4 inch, which is why it is often described simply as 3/4 inch stone. After crushing, the material is washed to strip out stone dust and fines, leaving a clean, open graded aggregate. This washing step is what separates #57 from a dense graded product like crusher run, and it is also what gives #57 its drainage performance. The angular, fractured faces left by crushing help individual stones grip and interlock with their neighbors, which partly offsets the lack of fines. Regional quarry geology drives the final color, so the same #57 specification can look gray and bluish from a granite source or tan and buff from limestone.

Because #57 stone is open graded, it performs very differently depending on what sits under it. For driveways, patios, or any load bearing use, start by excavating the area, then compact the native subgrade so it will not act as a soft, uneven cushion. Roll out woven landscape fabric across the subgrade before placing stone, which stops the aggregate from sinking into soil over time and keeps mud from pumping up through the voids during wet seasons. Spread #57 in the 4 to 6 inch range for driveways, or thinner for drainage and decorative uses, then run a plate compactor over it in lifts rather than trying to compact one thick layer at once. Install edging such as metal, plastic, or paver borders along the perimeter, since loose stone will migrate outward without a physical stop. For french drains and backfill, wrap the stone in filter fabric to prevent long term silt infiltration.

Compared with #4 stone. #4 stone runs larger, roughly 1 to 2.5 inches, and is favored for heavier drainage and erosion control jobs. #57 stone is smaller and easier to walk or drive on, which is why it dominates driveway bases and everyday drainage work where #4 would feel oversized and uneven underfoot.

Compared with crusher run or #411. Crusher run keeps its stone dust and fines, so it compacts into a hard, dense driving surface. #57 stone has those fines washed out, so it drains far better but never locks up as solid. Use crusher run when you need a structural surface, #57 when drainage matters more.

How much number 57 stone do you need. Estimate cubic yards with length in feet times width in feet times depth in feet, divided by 27. At 2 inches deep, one cubic yard covers roughly 100 square feet, at 4 inches it covers about 50 square feet, so double your depth and you halve your coverage. To convert to tons, multiply your cubic yard total by about 1.2 to 1.4, since a cubic yard of #57 weighs roughly 2,400 to 2,500 pounds. Always round up slightly to cover an uneven subgrade or extra compaction settling.

How number 57 stone is sold and delivered. Number 57 stone is sold in bulk by the cubic yard or by the ton, and it moves in loose, uncompacted form on dump trucks for drop off directly at a driveway, job site, or staging area. Because it ships loose, actual delivered volume can settle slightly during transport, so ordering a small buffer above your calculated need helps avoid a second delivery. It is typically not sold bagged, since bulk delivery is far more cost effective for the tonnage most projects require.