Terms of use

The patent drawings and specification text reproduced on this site are works of the United States government and are in the public domain. You may copy, share, print, and reuse them without asking anyone, including us.

Our original text — descriptions, commentary, and editorial matter — is copyrighted. Quote it with attribution; don't republish it wholesale.

This site is a hobbyist reference. We work from original documents and correct errors when found, but we make no warranty of accuracy and accept no liability for decisions made from it — including purchases, appraisals, or restorations.

This site does not sell anything and does not collect personal information beyond standard analytics. See Privacy.