Starrett 12 inch Combination Squre

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SMALMALEKI

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Following much thinking I bought myself a new combination square. It arrived today.
Starrett C9-12-4R Combination Set, With Cast Iron Heads, Centring, Square And Protractor Heads, Black Wrinkle Finish, Satin Chrome Blade, 12", 4R Grad https://smile.amazon.co.uk/dp/B003D7JUV2/ref=cm_sw_r_cp_api_fabc_HcH6FbDCHQPB4?_encoding=UTF8&psc=1

First thing to do was to check the squareness which was spot on. Then I checked the protractor which is not fine.
the lines on the body do not correspond to zero on both sides at the same time and when it’s set to zero the ruler has a degree of malalignment with the base.
Is there any was to fine tune it or shall I simply return it back?
 

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Well, I am disappointed in that because I thought that starrett was a brand that you could buy and have faith that it would be perfect.

It isn't right, so it needs to go back. I can't see much from the pictures but if 0 and 180 are not on the same plane then it is useless.

I bought mine from a strange company, I will try and find the name. Strange in that it isn't a supplier that I have ever seen mentioned but it was well priced.

Starrett can be hard to shop for because they have several models which look the same but have different part numbers. Workshop heaven would be a reasonable starting point for a replacement. Different part numbers but a few quid cheaper.
 
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Well, I am disappointed in that because I thought that starrett was a brand that you could buy and have faith that it would be perfect.

It isn't right, so it needs to go back. I can't see much from the pictures but if 0 and 180 are not on the same plane then it is useless.

I bought mine from a strange company, I will try and find the name. Strange in that it isn't a supplier that I have ever seen mentioned but it was well priced.

Starrett can be hard to shop for because they have several models which look the same but have different part numbers. Workshop heaven would be a reasonable starting point for a replacement. Different part numbers but a few quid cheaper.

Hi Marcros

I was under the exact impression. I’ve taken few more photos attached.
 

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I suggest you turn the protractor to 90º and check it to the square head (lock the square head and slide the protractor to touch and see what the reading is. If the 90º is out too much then return it. The protractor at best is a plus or minus 1º tool because you have to rely on your eye to align to and split lines for a reading. For most uses the tool is made for that and is good enough. If you are working to angles that require a tighter tolerance, segmented turnings for instance, then you should be using a vernier bevel protractor or a digital electronic equivalent that can measure to 5 minutes or less of a degree.

I have a Mitutoyo cast protractor and a Starrett forged head protractor and they are a little better than what I can see in your pictures but without playing with yours myself I'm reluctant to condemn it or the brand. In the end you will have to decide whether it is acceptable. I would send the pictures to the seller and see how they respond.

Pete
 
I suggest you turn the protractor to 90º and check it to the square head (lock the square head and slide the protractor to touch and see what the reading is. If the 90º is out too much then return it. The protractor at best is a plus or minus 1º tool because you have to rely on your eye to align to and split lines for a reading. For most uses the tool is made for that and is good enough. If you are working to angles that require a tighter tolerance, segmented turnings for instance, then you should be using a vernier bevel protractor or a digital electronic equivalent that can measure to 5 minutes or less of a degree.

I have a Mitutoyo cast protractor and a Starrett forged head protractor and they are a little better than what I can see in your pictures but without playing with yours myself I'm reluctant to condemn it or the brand. In the end you will have to decide whether it is acceptable. I would send the pictures to the seller and see how they respond.

Pete

The problem is that the seller is Amazon and they wouldn't know whether it is good, bad or indifferent. I am sure that we all use Amazon, but it is a valid reason for using the smaller retailers who actually know and use what they sell.
 
I suggest you turn the protractor to 90º and check it to the square head (lock the square head and slide the protractor to touch and see what the reading is. If the 90º is out too much then return it. The protractor at best is a plus or minus 1º tool because you have to rely on your eye to align to and split lines for a reading. For most uses the tool is made for that and is good enough. If you are working to angles that require a tighter tolerance, segmented turnings for instance, then you should be using a vernier bevel protractor or a digital electronic equivalent that can measure to 5 minutes or less of a degree.

I have a Mitutoyo cast protractor and a Starrett forged head protractor and they are a little better than what I can see in your pictures but without playing with yours myself I'm reluctant to condemn it or the brand. In the end you will have to decide whether it is acceptable. I would send the pictures to the seller and see how they respond.

Pete

Hi Pete

thank you for your very details explaining. I have tested it as you said pictures attached. I can see the ruler is not flash with the base plate of protractor. I mainly gonna use it for an square but the issue came out when I started to test different heads.
 

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It doesn’t look like you have it exactly at 90 degrees, close enough yes but not exact.
 
That’s a bit of a shocker.

According to the Workshop Heaven website:

“Although there is no current standard for combination squares, Starrett continue to manufacture to a now obsolete U.S. federal specification of 0.004in per foot max deviation between the square head and the blade, 3 minutes of a degree max deviation for centre heads, 15 minutes of a degree for protractor heads with blade edges straight to 0.001in.“

It may be worth getting a refund from Amazon and trying WS Heaven or Classic Hand Tools - at first glance they appear to be cheaper and I am sure if you ask when ordering they will check it before sending out.

Cheers
 
Here are a couple phone pictures of mine with the protractor heads tight to the square head. The Starrett is out a touch but probably within the spec Blackswanwood quoting and the Mitutoyo looking a bit better. Like I said if you want better you need a vernier bevel protractor or better. Yours should go back.
Pete
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I contacted them yesterday and got a replacement square. The new one is pretty close and square too.
 

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