diff --git a/src/build123d/build_common.py b/src/build123d/build_common.py
index 67431cbd..69484f4a 100644
--- a/src/build123d/build_common.py
+++ b/src/build123d/build_common.py
@@ -96,9 +96,9 @@
 THOU = IN / 1000
 
 # MASS CONSTANTS
-GM = 1
-KG = 1000 * GM
-LB = 453.59237 * GM
+G = 1
+KG = 1000 * G
+LB = 453.59237 * G
 
 operations_apply_to = {
     "add": ["BuildPart", "BuildSketch", "BuildLine"],