Safe-T 41516 T-Square

Along its top edge, this 9-1/2" transparent orange plastic rectangular instrument has a scale of inches divided to 1/16" for four inches and to 1/10" for four inches and numbered by ones from 1 to 8. The bottom edge has a centimeter scale divided to millimeters and numbered by ones from 0 to 20. Two rectangular indentations running the length of the instrument have holes drilled every 1/2-inch for drawing vertical lines. The holes are numbered from 3-1/2" to 0" to 3-1/2".
A lip underneath the instrument's left end serves as a guide rail when the T-square is placed on the edge of a clipboard or drawing board. Unlike a conventional T-square, this object has no crosspiece. This was supposed to make it easier to use. A hole at the right end permits hanging or placement in a three-ring binder. The device is marked: VIEW THRUTM; SAFE-T T-SQUARE®; SAFE-T PLASTIC®. It is also marked: Pat. (/) Pend. This patent was not identified.
Safe-T Products, Inc., of La Grange, Ill., was established in 1992 to sell drawing instruments that were safe for schoolchildren. In 1998 and 2000, Safe-T sold model 41516 for $1.95. In 2006, the company became a subsidiary of A. Daigger & Company and its name changed to Classroom Products Warehouse.
References: accession file; SAFE-T Products, Inc., Innovative Safe Drawing and Measuring Instruments, about 1998; Safe-T/Basics by Extra Measures, Inc., about 2000.
Currently not on view
Object Name
date made
Safe-T Products, Inc.
Physical Description
plastic (overall material)
overall: 24.1 cm x 5 cm x .3 cm; 9 1/2 in x 1 31/32 in x 1/8 in
place made
United States: Illinois, La Grange
ID Number
accession number
catalog number
Squares and Triangles
Science & Mathematics
Drawing Instruments
See more items in
Medicine and Science: Mathematics
Squares and Triangles
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of Extra Measures, Inc.

Visitor Comments

Add a comment about this object

**Please read before submitting the form**

Have a comment or question about this object to share with the community? Please use the form below. Selected comments will appear on this page and may receive a museum response (but we can't promise). Please note that we generally cannot answer questions about the history, rarity, or value of your personal artifacts.

Have a question about anything else, or would you prefer a personal response? Please visit our FAQ or contact page.

Personal information will not be shared or result in unsolicited e-mail. See our privacy policy.

Enter the characters shown in the image.