What is a steel hatch?

A steel hatch is a set of evenly spaced parallel lines, conventionally at 45 degrees, used to fill a cut through structural steel. It matches the ANSI31 pattern used throughout structural documentation.

How do I import a steel PAT file into AutoCAD?

Save the .PAT file in a support path, run HATCH, choose Custom and select the steel pattern. Keep the hatch scale at 1 and check the spacing with DIST across ten lines.

Can I use this steel hatch in Revit?

Yes. Import it as a Drafting fill pattern so the line spacing stays constant on the sheet regardless of view scale, which is usually what structural details need.

Can I change the angle and spacing?

Yes. Both are parameters. Use 45 degrees at close spacing for most members and mirror the angle to 135 degrees where two steel elements meet.

Steel Hatch Generator

Create the standard ANSI31 style steel section hatch and export it as a .PAT file.

Free

Material library

Choose a common building material as a starting point.

Steel loaded. Adjust any parameter below.

Pattern parameters

These values are written into the PAT file.

Pattern name

Generated automatically from the pattern type and dimensions.

Units

Pattern size

Module of the material symbol. Scales the whole hatch.

Rotation

deg

Scale

Multiplies every exported distance in the PAT definition.

Live preview

180 mm wide

PAT definition

steel_30.pat

;; Generated with ArchSupply Utilities - Hatch Pattern Generator;; Drawing units: millimetres (metric pattern);; Load in AutoCAD with HATCH > Custom, or in Revit via Manage > Additional Settings > Fill Patterns.*STEEL_30, Steel: ANSI31 45 degree section hatch, 30 mm spacing45, 0,0, 0,30

PAT definition ready

PAT output is in beta. Verify the pattern scale after importing into your CAD or BIM application.

About the steel hatch

Cut steel is drawn with evenly spaced 45 degree lines, the convention behind the familiar ANSI31 pattern. Beams, columns, plates, cleats and connection details all use it, and structural drawings depend on the spacing staying tight and consistent.

Because steel sections are usually small on the page, spacing matters more than texture. This generator lets you set the line spacing precisely so a 10 mm flange still reads as hatched steel rather than a solid black sliver at 1:10.

Flip the angle to 135 degrees to distinguish adjacent members that touch in a connection detail, then export the PAT file for AutoCAD or import it as a Revit drafting pattern.

How to use the PAT file

Download the .PAT file, or copy the definition into your own pattern library file.
AutoCAD: place the file in a support path, then choose Hatch, Pattern type Custom and pick the pattern name.
Revit: Manage, Additional Settings, Fill Patterns, New, Custom, then import the .PAT file and set the import scale.
Metric patterns assume millimetre drawing units; imperial patterns assume inches.

Frequently asked questions

What is a steel hatch?: A steel hatch is a set of evenly spaced parallel lines, conventionally at 45 degrees, used to fill a cut through structural steel. It matches the ANSI31 pattern used throughout structural documentation.
How do I import a steel PAT file into AutoCAD?: Save the .PAT file in a support path, run HATCH, choose Custom and select the steel pattern. Keep the hatch scale at 1 and check the spacing with DIST across ten lines.
Can I use this steel hatch in Revit?: Yes. Import it as a Drafting fill pattern so the line spacing stays constant on the sheet regardless of view scale, which is usually what structural details need.
Can I change the angle and spacing?: Yes. Both are parameters. Use 45 degrees at close spacing for most members and mirror the angle to 135 degrees where two steel elements meet.

Related materials

Every material opens the same generator with its pattern preloaded.