30mm dumbbell/barbell thread

I'm using 30mm barbells/thumbbells at home and wanted to create a helper-tool for benchpressing. After 3 days of studying thread-tables I still not found the corresponding thread-measures and so took a vernier caliper and a scale and created the thread my self.
The published STL-files contain one complete turn of the inner and outer thread of those 30mm barbells/dumbbells. Just put them one on top of the other as often you need, cut them off on the desired height and print your thread.
Inner thread has 0.5mm tolerance compared to outer thread.
STL-files are upscaled by factor 1000.