Design drilling layouts with clear coordinates, smart checks, and fast pattern options. Generate printable outputs, shareable tables, and dependable dimensions for accurate shop drawings.
Sample rectangular grid with 4×3 holes, origin (0,0), pitch X=50, pitch Y=40, diameter=12.
| # | X | Y | Diameter |
|---|---|---|---|
| 1 | 0 | 0 | 12 |
| 2 | 50 | 0 | 12 |
| 3 | 100 | 0 | 12 |
| 4 | 150 | 0 | 12 |
| 5 | 0 | 40 | 12 |
| 6 | 50 | 40 | 12 |
| 7 | 100 | 40 | 12 |
| 8 | 150 | 40 | 12 |
Rectangular grid: x = x₀ + i·pₓ, y = y₀ + j·pᵧ where i and j are zero-based indices.
Linear pattern: x = x₀ + k·p·cos(θ), y = y₀ + k·p·sin(θ), with θ in degrees.
Bolt circle: radius r = PCD/2, angle α = α₀ + k·(360/N), then x = xᶜ + r·cos(α), y = yᶜ + r·sin(α).
The calculator also reports coordinate bounds for quick plate sizing checks.
Consistent hole coordinates prevent field rework, misfit bolts, and oversized slots. For structural plates and base connections, patterned drilling improves repeatability and supports faster inspection. A coordinate table also helps verify part orientation and confirms that datum choices match the shop drawing before fabrication begins.
Set the origin at a corner, centerline intersection, or a marked datum on the workpiece. For rectangular grids, an origin at the plate corner simplifies layout. For circular patterns, centering at the true rotation axis reduces cumulative error in radial drilling and fitting.
Use equal pitches when possible to simplify jigs and CNC programs. Common shop grids range from 25 to 100 millimeters, depending on connection size. Verify that pitch exceeds hole diameter plus required clearance, and consider edge distance rules to reduce tear-out and bearing failures.
Linear drilling is common for clip angles, stiffeners, and rail anchors. Enter a pitch and a line angle to generate offsets along a chosen direction. A 0 degree line runs along the X axis, while 90 degrees aligns with Y, making quick alignment checks straightforward.
Circular patterns are used for flanges, handrails, and equipment baseplates. With a pitch circle diameter, the radius is half of PCD and holes are spaced by 360 divided by the hole count. Use a start angle to match keyways, slots, or indexing marks.
Round coordinates to match the tolerances required by the project and the measuring method. Layout with tape and punch may use one or two decimals, while CNC drilling can keep three or more. Consistent rounding prevents mixed values in the cut sheet and reduces confusion.
The reported minimum and maximum X and Y values define the pattern envelope. Compare spans to available plate size or fixture travel before cutting. For bolt circles, bounds also reveal whether the circle clears nearby edges, welds, or stiffener lines.
Download the coordinate table as a spreadsheet-friendly file for review, or a printable sheet for the shop floor. The exported list supports CNC input, quality checks, and quick re-measurement after coating. Keep the same unit system end-to-end to avoid conversion mistakes. Include revision date and job number on prints so operators can trace updates during production with fewer delays.
PCD is pitch circle diameter, the diameter of the circle passing through all hole centers. The radius used for coordinates is PCD divided by two, and holes are spaced evenly by 360° divided by the hole count.
For performance, keep totals at 5000 holes or fewer. This is usually enough for plates, flanges, and anchor templates. If you need more, split the layout into zones or export multiple runs with different origins.
Warnings appear when pitch or circle spacing is smaller than hole diameter plus your minimum edge distance setting. This helps catch tight layouts early. Always confirm the project specification for edge distance, bearing, and minimum clearances.
Use the same unit system as your drawings and measurement tools. Staying consistent reduces conversion mistakes and prevents mismatched CNC inputs. If you must switch units, recheck hole diameter, pitch values, and exported tables after converting.
The line angle rotates the pattern from the positive X direction. An angle of 0° moves holes along X, 90° moves along Y, and negative angles rotate clockwise. This matches common coordinate layout practice in fabrication drawings.
Many CAM tools accept a coordinate list, but formats vary. Use the CSV to review, then map columns to your software’s import fields. Confirm whether the machine expects absolute coordinates, local offsets, or a different axis orientation.
Pick rounding that matches how the work will be laid out. Manual marking often uses 1–2 decimals, while CNC can keep 3–4. Use consistent rounding across all outputs so the shop floor and inspectors read identical values.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.