Does an ISO(or equivalent) standard exist for relating color to fastener size?
I’m organizing some printed elements I use repeatedly and I realized I use Trilobe* holes, a lot.
I’m consolidating them into a reference file and want to color code by fastener size, so I can tell an M3 hole from an M4 Hole at a glance. If a standard exists, I’d prefer to follow it rather than reinvent the wheel.
No such standard exists as far as I’m aware of. How exactly are you planning such a color to fastener size indication? On the fastener? On the part?
@ThantiK I know in the US threaded rod tends to have color coding on the end; 1/4-20 = Blue, 5/16-18 = Red, & 3/8-16 = Yellow…I just now realized that may not be a standard.
I’m curious if something similar exists on the metric side.
I’m seeing it from the CAD design side. Color coding different fastener diameters would help to quickly verify the diameter of the fasteners I’m using in non-critical applications.
Maybe I’m overthinking it, but I really like designs where I can minimize the number of different diameter/length hardware. It’s typically overkill but its so much easier to work on/maintain the design.
I’ve not seen rod colour by size, I’ve seen it by material though. I’ve seen different grades of stainless steel tube & rod have specific colours related to their grade (like 304, 316, etc)
@Steve_M maybe it’s a retail thing?
I think it repeats Blue->Red->Green b/c I looked around the garage and found this 5/16" w/ Red and 1/2" w/ Blue.
They’re both zinc plated threaded rod, no difference in grade. I guess it’s just something Lowes/Home Depot do for inventory management(?)
Curious what the benefit of the trilobe hole is?
@Ryan_Carlyle a standard machine screw can self tap into it. It’s not as strong as a fully modeled thread, but the geometry is much simpler.
For example my Deltesian Effector has the blind M3 Trilobe holes for all the joints: https://imgur.com/HfROgwv
@Rob_Stuart_bornity Got it, thanks. How’s the sensitivity to print tolerances? Is it something that works for other people if you share the model, or just for your own parts? (I’m sure you’re familiar with the typical tolerance issues most people have with inside holes in FDM prints.)
@Ryan_Carlyle I’ve found it to be pretty forgiving. The Minor & Major offsets based on the thread pitch provide enough room for some of the material to be displaced with out gumming up the threads and friction stripping the hole.
On the M3, for ex. the 3.3mm oversize tends to be about ~3.1mm when printed but there is enough room for the screw to still grab effectively. You can hand tap it with a screw driver. You can over torque it by hand and strip the hole but if you don’t over do it, you’re fine.