[Go-Go-Legoman]

Hey all, can you guys tell me how well 5/16"-18 carriage bolts fit in the grooves of 80/20's 15-series struts? I've been drafting a cad model of the machine I'd like to build and it seems that the width of the bolts' square neck is bigger then the T-channel of the 15 series.

McMaster's 5/16"-18 bolts have .324" necks and the T-channel of the 15 series range from .320" to .3121", depending on whether the 2 degree drop-lock feature is engaged. I'm getting the T-channel measurements from 80/20's own cad drawings.

[DonFrambach]

For my build, I used cheap carriage bolts that I buy by the pound at a local home center. Every one of the 5/16" carriage bolts fit just fine into every one of my 8020 series 15 extrusions.

You prompted me to make some measurements. The slot size in a piece of 8020 scrap measured .321. The square neck of several carriage bolts measured between .308 and .312.

Just remembered, I bought some of my carriage bolts from McMaster and they worked just fine too.

[brtech]

I got some 93548A587 bolts from McMaster. They worked fine in 3030 and 1530.

[Go-Go-Legoman]

Thanks for the reply guys! That'll cut down a bit on me second-guessing myself :P