Screws or bolts etc

Hi all, got a small list of items needed for the Primo build with a note of hex heads and pan heads etc except that the list doesn’t actually specify which one is which?

Is there a detailed list saying exactly what each one is so I can source them properly?

Thank you.

Hi @vicious1 thank you for that. I had already been to that page, but using the list and searching in Google/eBay/Amazon gives me multiple answers:

Hardware Alternative QTY Comment
5/16x1.5” M8x40mm 46 <- Using the image of the upgrade pack I figured these were HEX Head Partially Threaded, but it’s not detailed in the description here
5/16 locknut M8 locknut 46 <–Got these sorted
M5x30mm 65 <-- Got these sorted via the same image
M5 locknut 65 <-- Got these sorted
M3x10mm 24 <-- Not sure on these, pozi allen hex etc
M2.5x12mm #3x½“ 10 <-- Not sure on these, pozi allen hex etc

This version uses both sizes of hardware equally well. No issues with metric bolts what so ever.

Bolts need to be hex head, screws pan head. If you choose to use cap head you will need washers and perhaps a little extra length.

Any extra help here or a pointer on how to figure out which is which would be fab.

Thanks again.

The note doesn’t clear it up for you?

I am trying to understand how to make it more clear. Should I add a column to label each one a bolt or screw?

The bolts do not have to be partially threaded, that is just what I have.

I would have ‘bolt’ or ‘screw’ in the hardware description somewhere. M3x10 could be either a bolt or screw. Same for the others too, I think.

The M3x10 machine screws are for mounting the stepper motors. These thread into holes in the motors so no nuts are needed. Head probably doesn’t matter, I got hex heads from my supplier but allen head cap screws would have worked fine too.

I think the M2.5x12mm are pan head screws for mounting the feet to the board and for securing the lead screw nut.

Looking back at the posted lists, the Upgrade chart does list screw or bolt, but the hardware list for the Primo build pack is missing those terms.

guys thank you all very much for your responses, that helps massively.

Ryan yes, that sounds like a fab idea. I think having a dedicated column that described what kind each line is would be brilliant, especially for someone like me just coming in off the streets and not knowing exactly what is what :slight_smile:

Much appreciated!

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Same happened here,

I didn’t see or understand the difference M5 screw of M8 bolt.
Apparently everything above M5 is considered a bolt and under is a screw?
Or does the cross head pan head make it a screw?
Here in the Netherlands we call everything with metric thread “bout” (bolt).

So i came home with M5 hex heads which didn’t fit, changed them out for M5 allen head at work.
They fit fine except tensioning the M8 besides the steppers a little bit difficult.

Oh and sidenote: the primo was much easier to assemble than the burly was, big steps were made!
The nut traps being the right size for metric nuts was so much easier

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I’m in the U.S. When I buy fasterners from the hardware store, threaded fastners without a hex head are referred to as “machine screws.” This includes M8 and 1/4" fastners. If it is labeled just “screws,” it will be tapered and labeled with what they are used for like, wood screws, deck screws, drywall screws, and sheet metal screws.

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|5/16x1.5”|M8x40mm|46|<- // Hex heads. 13mm if you’re using actual M8s typical, 1/2" for 5/16"|
|5/16 locknut|M8 locknut|46|Typically sizes same as for bolts.|
|M5x30mm||65|Pan head, Phillips screwdriver bit, though mine are 3mm allen key pan heads. 8mm hex head bolts OK MOST USES. Some places will be tight getting into, pan head highly recommended|
|M5 locknut||65|Typical 8mm wrench size nut, required for captive nuts. Careful, some out there are 7mm wrench size!|
|M3x10mm||24|Used to screw motors to mounts. Phillips head OK, 2.5mm hex cap OK, 2mm hex pan head OK.|
|M2.5x12mm|#3x½“|10|Used to attach limit switches. Screw into plastic. Phillips head OK, 1.5mm hex pan head OK, hex cap screws OK.|

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Thank you all. I can see Ryan updated the details on the hardware page so i’ve got the rest of my nuts, screws and bolts ordered. Just some last parts now :slight_smile: The wiring… I get the feeling I might need some more tools for that too.

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Some interesting variations in interpretation - here’s another:

A machine screw is fully threaded, a bolt is part-threaded - be it hex head, socket cap, Pozi, Phillips (sp?) Torx or any of the variants of security drive patterns.
How I was trained anyway.

Neither, needless to say, is a wood screw.

Wow crazy I googled Pozi drive as I did not know what that was. I am really happy I did.

I have seen what I now assume were Pozi drive and I always thought the were for the option for a square drive. which worked great but now I see they were Pozi drive I’m guessing. 66 years and still learning.

Anxious to quiz some friends. :grinning:

They cam out a little less easily than Phillips (and both locate more readily than slotted). Torx are OK, but I prefer them on larger fasteners (I’ve been putting floor boards into a loft recently using Torx head wood screws, and I don’t feel the heads have enough depth to really prevent cam out).

Oh, the angles are different between Pozidrive & Phillips too - they’re not really compatible.

Hi there,

Is there a valid reason to go for m8 “bolt” being hex topped? Why Can’t I use Torx or allen heads? For aesthetics reasons. I hate the hex bolts. :slight_smile:

The heads on the Allen ones are wider than the hex. If you want to try it, you could get a few bolts and try them in the parts.

You have to be careful. They usually have less surface area, so washer start to become a good idea, and they tend to be nearly twice as tall, so interference also comes into play in a few spots.

People still use them and just grind off some of the heads were needed.


Ok, So I got it backwards. Thanks Ryan.

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