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pinstripe
11-17-2016, 08:33 AM
Does this look worn or dirty? I'm not buying it, just wondering.

Also, what's the hole for?


http://i1168.photobucket.com/albums/r491/pinstripe2/HSM/SurfacePlate_zpsdrpfp0cx.jpg

JoeLee
11-17-2016, 08:40 AM
Impossible to tell if it's worn from a picture. The discoloration could be just oil or some other staining, or even natural to the stone.
The hole was probably for an indicator post or something.

JL..............

TGTool
11-17-2016, 09:30 AM
Looks worn to me. If recently scraped there should be polka dots of shiny points all over, not areas of shiny surfaces. That doesn't prove it's not usable. It needs comparison against a known good surface to form a judgement about that.

J Tiers
11-17-2016, 10:36 AM
Probably both worn and dirty, as it looks as if it had been used. Obviusly dirty, and used, so worn.

TOO worn? No clue.

Hole in middle probably for a post for some specialty measuring setup.

Doc Nickel
11-17-2016, 03:14 PM
If recently scraped there should be polka dots of shiny points all over, not areas of shiny surfaces.

-"Scraped"? You don't scrape granite. :) Granite plates are ground, and then then lapped to repair.

But I agree, the differences in appearance could indeed indicate wear. You simply cannot tell from a photo, you'll have to closely examine/measure it in person.

Doc.

softtail
11-17-2016, 03:43 PM
Lots of bicycle frame builders put posts in them (whippings posts) to hold the bike frame by the bottom bracket (crank bearings). Some even build off the plate... that looks to me like brazing char on the plate.

lynnl
11-17-2016, 04:01 PM
Looks like a cast iron plate to me. Looking down into the hole, it only looks like an inch or so deep.

old mart
11-17-2016, 04:32 PM
Hard to tell, looks like cast iron to me as well, it would be three inches thick if it were granite.
Also, look closely at the lower right hand corner.

Mcgyver
11-17-2016, 04:56 PM
if its a plate its not granite. Is it a plate? likes somewhat like a welded frame around it, but hard to tell. need more info and photos

pinstripe
11-18-2016, 04:15 AM
Thanks all. It was advertised as a granite surface plate. No other photo or details. It did cross my mind that it might just be a block of granite, but I didn't notice how thin it looks in the middle. It could be a shadow, but it does look very thin. It was going cheap at $100.

TGTool
11-18-2016, 11:25 PM
-"Scraped"? You don't scrape granite. :) Granite plates are ground, and then then lapped to repair.

But I agree, the differences in appearance could indeed indicate wear. You simply cannot tell from a photo, you'll have to closely examine/measure it in person.

Doc.

Right. On the other computer it looked like a metal plate.

Sorry about that, Chief!

old mart
11-19-2016, 10:45 AM
Ok, it's granite, but no way is it a surface plate.

Paul Alciatore
11-19-2016, 02:22 PM
Cheaper new at $40.

http://www.wttool.com/index/page/category/category_id/17550/




Thanks all. It was advertised as a granite surface plate. No other photo or details. It did cross my mind that it might just be a block of granite, but I didn't notice how thin it looks in the middle. It could be a shadow, but it does look very thin. It was going cheap at $100.

Mark Rand
11-19-2016, 03:51 PM
Cheaper new at $40.

http://www.wttool.com/index/page/category/category_id/17550/

Bear in mind that pinstripe is in Oz and prices there can be very different than they are in the US.

Peter.
11-19-2016, 03:59 PM
They sure as hell are here, I would love to be able to buy granite plates at those prices.

pinstripe
11-19-2016, 05:31 PM
Correct. $100 AUD is cheap for a used plate of this size here. I've seen slightly larger ones go for $300. In fact, this one sold the day after it was listed.

LKeithR
11-19-2016, 08:15 PM
...Also, what's the hole for?

The hole is where you tie the rope when you convert it to a boat anchor...;)

oldtiffie
11-19-2016, 09:23 PM
Whether or not the "plate" is "granite" or not and providing that it is "flat enough" for the purpose/s that you want to use it for then it having no "grade" is of no significant at all.

Same goes for "clean or dirty" - just use common (just how "common is it? - really) sense and clean it off until the part/s of the "flat" and "surface" is as clean and as useful as you only need for functional purposes.

My all-too-often-posted "float glass" "plate" is quite adequate for all or most of a flats and surfaces that I require.

My quite good surface plates rarely see the light of day.