Can a small granite surface plate be used as a square?

[daxliniere]

Can a small granite surface plate be used as a square?

 

[mart]

A square what?

 

[Screwdriver]

I believe you can buy such a thing...

 

[Brad93]

Granite squares are available.

The granite surface plates are not lapped square or flat on the sides. At best they diamond cut then polished smooth.

 

[daxliniere]

Granite squares are available.

Yes, but over £100 for something I'm going to use only a few times, it's a bit rich. For an engineering shop producing parts to other people's specs; yep, absolutely. Worth spending even more, I'd say.

I was hoping I could pick up a small used surface plate (<300mm) for cheap, but that's good to know about sides not being lapped square. Thanks for the heads-up, Brad.

 

[Brad93]

Yes, but over £100 for something I'm going to use only a few times, it's a bit rich. For an engineering shop producing parts to other people's specs; yep, absolutely. Worth spending even more, I'd say.

I was hoping I could pick up a small used surface plate (<300mm) for cheap, but that's good to know about sides not being lapped square. Thanks for the heads-up, Brad.

Yep i don't know if you've seen/used a granite square, but if you have then you'll understand why they don't make them like the surface plates 4-5" thick... weight. Imagine trying to repeatedly move a 30kg high precision/fragile block.

£100 is for the triangular chinese ones (albeit they are okay, i believe a few members on here have bought them)

"Real" granite squares are lapped on at least 4 edges but also sometimes 5 sides.

I've got a 300mm square Crown (Eley Metrology)
It's about 40mm thick with big holes in the middle to reduce weight and give you something to hold.

Best part of £600 new.

 

[Screwdriver]

Cylinder square might be a more cost effective option. I don't know how true that may be (no pun intended) but it occurs to me they might be easier to produce.

 

[Brad93]

Cylinder square might be a more cost effective option. I don't know how true that may be (no pun intended) but it occurs to me they might be easier to produce.

Depends if you have a cylindrical grinder, a known good surface plate and a way of lapping the base.

 

[Milkybars]

@daxliniere It won't help your cause in relation to a sqaure but I do have a small granite surface plate going cheapish round in Ilford as part of project clear out

 

[pressbrake1]

Don’t assume it’s square!
It’s a surface plate not a square so edges are not going to be very square, or co plainer

 

[Hitch]

Buy a granite tile from wickes... it'll be as square as half the squares that are for sale these day.
Or buy a square....

 

[daxliniere]

Thank you, everyone!

 

[daxliniere]

@daxliniere It won't help your cause in relation to a sqaure but I do have a small granite surface plate going cheapish round in Ilford as part of project clear out
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Thanks for the heads-up, Milkybars, but I'm good for now.

 

[Memmeddu]

Cylinder square might be a more cost effective option. I don't know how true that may be (no pun intended) but it occurs to me they might be easier to produce.

Old piston pins are great for many applications ,I found myself using them(35mm diameter x 100mm long) for setting up things on machines .
They are precision ground on the flat surfaces too + they are hard as hell but they still not brittle since we use on the hydraulic press too

 

[Brad93]

Old piston pins are great for many applications ,I found myself using them(35mm diameter x 100mm long) for setting up things on machines .
They are precision ground on the flat surfaces too + they are hard as hell but they still not brittle since we use on the hydraulic press too

Gudgeon pin

 

[Screwdriver]

Old piston pins are great for many applications ,I found myself using them(35mm diameter x 100mm long) for setting up things on machines .
They are precision ground on the flat surfaces too + they are hard as hell but they still not brittle since we use on the hydraulic press too

Sounds like a great idea. You'd really want a great big one though!

 

[Brad93]

 

[Beeezer]

If you have the imagination it can be anything you would like it to be…..