Description
Please note that some color combinations are on sale!
The Bike Scruler - a screw measuring device which covers the metric sizes found on modern bicycles. Measures M3, M4, M5, M6, M8 and M10 sizes with a simple cutout, measures the length of the screw (can be read to half a millimeter!) and can check for common bike thread pitches: M3x0.5, M4x0.7, M5x0.8, M6x1.0, M8x1.25, M8x1.0, M10x1.50 and M10x1. Also includes a pair of magnets in the back which allow it to stick to any ferrous surface.
New version 2.0 - includes cosmetic improvements with multi-color printing not visible from the edges, but more importantly, aluminum inserts for the M3, M4, M5 and M6 thread checkers. This ensures better thread quality and durability. The M8 and M10 threads are still printed as they are coarser and don't need the inserts as much.
NOTE on materials. I've switched to PETG plastic (a similar material to that used in bottled water bottles) which has good characteristics including high temperature resistance. However, some of the "fancier" colors like the shiny gold aren't available in PETG and so I use PLA. PLA will work just fine, but you should know that it doesn't have the same temperature resistance. As long as you don't leave it on the dash of a car on a sunny summer day, it is just fine. My personal versions are all printed with PLA but it's best that you know that it doesn't handle extreme heat well.
USAGE:
To get an accurate reading, the top of the mark is the exact length, and the mark is 0.5mm thick. The top of the next mark is on the opposite side and is the next millimeter length. I've been able to accurately measure bolts to a half a millimeter with this gauge - not that you'll often have to do that.
Measuring conventional screws is easy - put the threaded part in the channel and then slide the head up to the end and measure directly. The top of each cutout is the measurement, and the cutout is 0.5mm wide, so it's possible to accurately measure to 0.5mm, not that that level of accuracy is often needed.
Measuring flat head screws is trickier as their rated length is from the top of the head, so I find it best to use something flat across the top (a tire lever or cone wrench works well) and then hold the screw up against that. It's a little more work but you can still get good measurements.