Inserts in granite angle plate

[Maverick302]

I picked up a couple surface / angle plates with the purchase of my mill. The two angle plates have threaded and solid inserts in them. Can anyone shed some light on what the inserts are used for? The only thing I found by googling was compatibility with magnetic chucks, is that their only purpose?

 

[stupoty]

I picked up a couple surface / angle plates with the purchase of my mill. The two angle plates have threaded and solid inserts in them. Can anyone shed some light on what the inserts are used for? The only thing I found by googling was compatibility with magnetic chucks, is that their only purpose?

their probably used for connecting other jigs or clamps to for intricate measurement.

a bit like this perhaps ,

Stu

 

[Dabbler]

On normal angle plates you can and do use C clamps and Machinists clamps on it to hold parts and fixtures, This is a NO-NO for granite angle plates. If you do you will wear it out quickly, ow worse crack it.

The inserts allow clamps and fixtures to be positioned onto it safely.

 

[Bob Korves]

Sometimes "surface plates" with threaded inserts are not surface plates at all. Sometimes they are parts of fixtures from production tooling completely unrelated to a surface plate, just a massive and well dampened plate for mounting tooling, calibration equipment, or other things. Sometimes they were never accurately flat at all, because it was not needed for the original purpose. Be careful of things for sale that are advertised as a "surface plate." Sometimes you can tell the original use by the names and dates cut into them and the words "rest in peace."

 

[chips&more]

I also have a few of those. Handy in a Metrology Lab, maybe not so much in a hobby shop? Because granite is not magnetic. The metal plugs allow you to attach the granite whatever to a magnetic surface. The threaded holes are for attaching stuff to the granite whatever. Good Luck…Dave

 

[Latinrascalrg1]

Is it possible that they are there to be drilled and tapped as needed by the owner for clamping purposes?

 

[Maverick302]

Sometimes "surface plates" with threaded inserts are not surface plates at all. Sometimes they are parts of fixtures from production tooling completely unrelated to a surface plate, just a massive and well dampened plate for mounting tooling, calibration equipment, or other things. Sometimes they were never accurately flat at all, because it was not needed for the original purpose. Be careful of things for sale that are advertised as a "surface plate." Sometimes you can tell the original use by the names and dates cut into them and the words "rest in peace."

It does have a DoAll nameplate with flatness grade and certification date, so I am dealing with a true surface plate. Good to know for future reference though.

Is it possible that they are there to be drilled and tapped as needed by the owner for clamping purposes?

The front face has inserts that are already threaded. The sides have larger diameter solid, ground (assuming hardened) inserts.

I also have a few of those. Handy in a Metrology Lab, maybe not so much in a hobby shop? Because granite is not magnetic. The metal plugs allow you to attach the granite whatever to a magnetic surface. The threaded holes are for attaching stuff to the granite whatever. Good Luck…Dave

I think you nailed it. Seems to make the most sense.

 

[Latinrascalrg1]

The front face has inserts that are already threaded. The sides have larger diameter solid, ground (assuming hardened) inserts.

Yes I noticed that which made me think the larger ones were left blank for customizing purposes?