Is there a standard size for work-holding fixture hardware?

Good morning everyone,

I am looking to add some alum. T-slots to my CNC machine's table along the edges to help me hold down some stock.
I have a few options ranging from offerings from 80/20 extrusion (which are not ideal since they have a bit of camber along the "flat sides") or mitusmi and Minitec to woodpeckers alum pro rails.

With all these different offerings and in order to make a good decision I would like to ask the community if there is a standard size more clamps and work-holding hardware comes in? Are there more 1/4" fastener types? 5/8? , M6 M8?
This information would allow me to make an educated assessment of what I want to do.

Thank you in advance.

Quote:

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Originally Posted by FoxCNC1

Good morning everyone,

I am looking to add some alum. T-slots to my CNC machine's table along the edges to help me hold down some stock.
I have a few options ranging from offerings from 80/20 extrusion (which are not ideal since they have a bit of camber along the "flat sides") or mitusmi and Minitec to woodpeckers alum pro rails.

With all these different offerings and in order to make a good decision I would like to ask the community if there is a standard size more clamps and work-holding hardware comes in? Are there more 1/4" fastener types? 5/8? , M6 M8?
This information would allow me to make an educated assessment of what I want to do.

Thank you in advance.

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The t nut size is usually dependent on the size (series) extrusion you're using. i.e. 45mm series usually has 10mm t slots.

thanks for your response and while I realize that, my question was more along the lines of what size Tnut do most fixtures use.

Quote:

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Originally Posted by FoxCNC1

thanks for your response and while I realize that, my question was more along the lines of what size Tnut do most fixtures use.

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There is no standards use but which you make ( to paraphrase a movie). Some companies promote T slots sized for toliet bolts but honeslty that can be limiting. If you go to 80/20 you can find Nuts, bolts, t-bolts and other goodies in a variety of sizes. My suggestion would be to use the largest bolt size possible for the hardware you are using. Keep in mind thought that large isn't always optimal.

I've mounted some t-slots in my table. They work great. I milled up a few pieces of alum bar to fit in the slot, drilled and tapped for a 10-32 (if I remember correctly) and cut some heads of the bolts and lock-tited the bolt shaft in the tapped hole.

Anyway here is a link to my build where these can be seen in a few pictures. I thought I had a post on just these, but I couldn't find it. I'll have to add that.

http://www.cnczone.com/forums/cnc-wo...cnc-forum.html

Quote:

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Originally Posted by FoxCNC1

thanks for your response and while I realize that, my question was more along the lines of what size Tnut do most fixtures use.

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There is no standard. You use what fits the machine.

Thank you guys. I am going to use some Tslot extrusion that takes a 10mm t nut

Quote:

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Originally Posted by FoxCNC1

Thank you guys. I am going to use some Tslot extrusion that takes a 10mm t nut

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If you try to use 10mm t-nuts designed for mill tables, I'd check the specs first to ensure they fit your extrusion. Otherwise it's probably easier to buy the t-nuts your extrusion manufacturer recommends and bolt your fixtures down with that. Some manufacturers make t-nuts for metric slots with SAE threads (I think Bosch does) so you can get stuff from Woodpeckers which uses 1/4"-20 threads....