T-slot nuts

Sorry if this has been answered before. Is there a cheap source for 1/4-20 T-slot nuts? $3.25 apiece seems like robbery.

They’re cheaper at McMaster: http://www.mcmaster.com/#extrusion-nuts/=ogdvl3

Although that’s still not cheap.

Are they for metric or standard extrusions? If you have a part number and a vendor, please post that as well. I looked through the 80/20 price list for 2013 and saw that standard 1/4-20 T-nuts for both 15 and 10 series (1.5" & 1") were $0.79 each (p/n 3202 & 3204). I can also tell you that our local 80/20 distributor has given us a steep discount on 80/20 parts and accessories, so your local one may be able to help you out that way, too.

Or are these for a mill? If so, McMaster, Grainger, or MSC would be good resources. It looks like (based on McMaster’s pricing) the 1/4-20 are more expensive than the 5/16.

Buying cheap 8020-esque items is a real struggle. However, a little while ago, someone on these very forums pointed me to towards TSlots (www.tslots.com).

Most of these prices are super nice as compared to the 8020 retail price, but on top of that, this company gives 50% off to FIRST teams every calendar month (you have to cover shipping). The parts are quality, and we have noticed no difference between 80-20 parts and TSlots parts.

There are many types of nuts, but the 1/4-20 Drop-in nut (which is super premium) is about $.86 after the 50% discount at T-Slots.

They’ve kept us happy; they’ve kept our business,

  • Sunny G.

Misumi is another alternative manufacturer to extrusions and have just as many profiles. Here is their search tool: http://us.misumi-ec.com/maker/misumi/mech/aluminum_extrusions/Extrusion-Browser.html. I believe their fasteners take metric hardware, though.

If you don’t need the 40mm square extrusions, OpenBeam (15mm) is built around standard M3 fasteners and can be bought through Amazon.

One note for everybody: if Dr. Bot is asking about aluminum extrusion T-Nuts, then they need T-Nuts which are compatible with those extrusions. I know for a fact (ie - I got burned professionally on this) that you cannot mix Bosch extrusions and 80/20 T-Nuts (and vice-versa) because the T slots on the extrusions are shaped differently.

However, $3.25 is about the right price for milling machine T-Slot nuts. I was able to find some online for about $2.50, but they were 5/16, not 1/4-20. :frowning:

I’ll have to look through my archives and see if I can dig it up, but I know 971 was able to modify some special nut we found at Orchard Supply Hardware to do the job. IIRC we could get them in packs of 20 for a few bucks, and all we had to do was hit them with a grinder to flatten out the sides and they worked like a charm.

I have a quite small mill, and it uses 3/8" (5/16-18) T-Nuts. 1/4-20 would be a mini-mill I suppose.

For 80/20 type stuff, I have used carriage bolts to good effect. Cheap too.

For a mill, my recommendation is to make them. Get some long steel bar, mill in the slots, drill and tap the holes, and cut it into nuts. Maybe not cost-effective at $60/hour, but student labor is cheaper…

Note: Don’t tap the holes all the way thru, to keep your studs from marring the bottom of the slot or, even worse, breaking the slot open.

When we say we built this robot from scratch WE MEAN IT!

We’ve used carraige bolts quite effectively as well. A few tips:

  1. We got ours from Lowe’s. Home Depot carraige bolts did not work for us. (I think the square at the top is larger at HD.)
  2. Bring a piece of your extrusion (typically 1010) with you to the store. Test them out on the extrusion. For us, about 70% will fit.
  3. Minor differences in sides of the extrusion may allow carraige bolt to work on one side, but not the others. Typically, it might work on two opposing sides (A and C) but not the other two (B and D). (Label sides ABCD, going around extrusion.) Extrusions are supposed to be identical on all four sides, they look identical, they are not quite identical. If you have a carraige bolt like this, grind off a bit of the top. (Make two flat sides on the bolt top, so the bolt fits easily. Maybe a good idea to grind all of your bolts a bit, if you have the time.

Thanks guys. I think Adafruit has what we need. It wasn’t 1/4-20s it was M4s They are closer to .20 a piece.