Saving, opening & exporting
Work is saved as an .h8prt/.h8asm/.h8drw history file that rebuilds on load; everything leaves through one Export ▾ menu — STEP, STL, DXF, SVG, PDF.
hammer8 runs entirely in your browser — no account, no cloud. Files live on your disk.
The hammer8 file
Save / Save As (top bar) write an .h8prt file (assemblies: .h8asm, drawings: .h8drw): it stores the feature history, not the final mesh, so it is tiny and rebuilds exactly on load — parts, assemblies and drawings all use it. Open and Recent bring a file back; the tab strip lets several documents stay open side by side.
- A part saved months ago still opens — the format is kept backward-compatible.
- Rename features in the tree before saving; names travel with the file.
Exporting
Everything leaves through one door: Export ▾ in the top bar (⌘/Ctrl E). It lists the formats that suit the open document — the others are greyed out, never hidden — and each one opens its own options dialog.
- Part or assembly — STEP, true B-rep solids, the format a supplier or another CAD package wants; and STL, a mesh for 3D printing whose tessellation follows the status-bar quality setting.
- Sheet-metal part — adds Flat pattern DXF: the unfolded blank with bend lines, for the laser or press brake (Sheet metal).
- Drawing — PDF (vector, to scale), SVG and DXF (2D drawings). Print stays on the drawing's own Sheet tab.
Importing
Import ▾ (⌘/Ctrl I) is the mirror image: STEP, IGES and BREP arrive as solids, STL, OBJ and 3MF as meshes, and DXF or SVG as 2D profiles dropped into a sketch. See STEP import, Import meshes and other formats and Import a DXF profile for what survives each round trip.
When it fails
- The browser asks where to save every time — use the same folder; Recent keeps the list.
- An old file shows warnings after opening — geometry references can go stale across big edits; see Fix a rebuild error for repairing them.
Related: Your first part (sketch → extrude) · A tour of the interface