i recently bought Starrett 3202 12" dial calipers

[LatheLover91106]

I recently bought Starrett 3202 12" dial calipers

First question is if i run my finger over the jaws to remove an little particles will that cause them to rust?

Second question is...is it normal to have a very small light gap when the jaws are touching....the gap is less than a thousandth...i opened them 1 thousandth and it was bigger than the gap...so is it normal to have a very very small light gap or should i have them inspected?

 

[Rob F.]

Arn't they made of stainless? So no worry about rust.
None of my calipers have any visible gap when closed, but I don't have your model either. Is there any kind of grime build up on the jaws or in the rack slot that is keeping them from closing?

 

[LatheLover91106]

Arn't they made of stainless? So no worry about rust.
None of my calipers have any visible gap when closed, but I don't have your model either. Is there any kind of grime build up on the jaws or in the rack slot that is keeping them from closing?

no there is no grime....i don;t believe, i ran my finger over the jaws to wipe them
if i put a little more pressure on them the gap goes away though
and yes they are hardended stainless...just wanted to make sure my fingers wont make them rust
and the gap is only visible when held up to a light...its very small but there against light....less than 1 thou

 

[Rob F.]

Close them on a piece of clean paper and pull out the paper while lightly snugging the jaws closed to be sure there is no grime build up. Tee shirt material also works and might be less abrasive.

 

[LatheLover91106]

Close them on a piece of clean paper and pull out the paper while lightly snugging the jaws closed to be sure there is no grime build up. Tee shirt material also works and might be less abrasive.

ok will do...and sorry for all the trouble and questions...im an 11th grade student of machining and earned money from my class and bought calipers....wanna make sure they are right lol
the paper mad it a little better...probably abt 1/4 of a thou now and i have just one more question for you....should the depth rod have some wiggle to it..like up and down....it doesnt slide in and out but wiggles up and down

 

[moosesgunsmithing]

ok will do...and sorry for all the trouble and questions...im an 11th grade student of machining and earned money from my class and bought calipers....wanna make sure they are right lol
the paper mad it a little better...probably abt 1/4 of a thou now and i have just one more question for you....should the depth rod have some wiggle to it..like up and down....it doesnt slide in and out but wiggles up and down

We all start somewhere. No shame in not knowing things. Every caliper I've had has a depth rod that wiggles some. If I need to be precise I'll use a depth micrometer or guage blocks or a combination of the two.

Do you have a 0-6 caliper yet? That's what I use the most. A good 0-1 micrometer, 0-6 dial caliper, and a 0-1 0.0005 dial indicator covers probably 80-90% of my measuring and indicating needs, but your mileage may vary. Ebay has been a good source for tools if you are on a budget and can wait. If you have access to good standards or even higher quality gauge blocks you can calibrate a used micrometer fairly easily.

 

[Rob F.]

How do you tell the calipers are 1/4 thou when closed? If you don't know yet the dial will turn so you can set zero. So run the paper through, close them and turn dial to read zero and you should be good to go.

 

[LatheLover91106]

We all start somewhere. No shame in not knowing things. Every caliper I've had has a depth rod that wiggles some. If I need to be precise I'll use a depth micrometer or guage blocks or a combination of the two.

Do you have a 0-6 caliper yet? That's what I use the most. A good 0-1 micrometer, 0-6 dial caliper, and a 0-1 0.0005 dial indicator covers probably 80-90% of my measuring and indicating needs, but your mileage may vary. Ebay has been a good source for tools if you are on a budget and can wait. If you have access to good standards or even higher quality gauge blocks you can calibrate a used micrometer fairly easily.

i bought a 12"dial caliper for more use in. i am figuring when i start a job on a lathe or mill that it will probably be bigger than 6" while in the workplace, so i got 12" which just means i can do even more. I just thought chnaces are my parts at work will be bigger than 6

 

[LatheLover91106]

How do you tell the calipers are 1/4 thou when closed? If you don't know yet the dial will turn so you can set zero. So run the paper through, close them and turn dial to read zero and you should be good to go.

i just meant the gap was probably about 1/4 thou when closed....but my instructor said its normal...all calipers hes had have a very very small light gap only visible when held up to a very bright light. he said for no gap use a mic.

 

[M.B. Naegle]

...im an 11th grade student of machining and earned money from my class and bought calipers....

Fantastic! Glad to see the next generation investing in the future like this!

For calipers, that much of a gap isn't a big deal IMO. Not to say it shouldn't be better, or that you couldn't make it better (I've know guys to dress the jaws with a hone), but considering it's .001" resolution, ideally it only needs to be repeatable to the nearest 1/2 thou.

 

[michiganbuck]

Sometimes a .0001 gap shows as blue light and white at .ooo2 I don't know why.
RE: (depth rod have some wiggle to it) Almost all running fits will have .0002+ to run(travel) with not galling.
Do have the ability to check the squareness of a part, and how to come into an existing screw thread on the lathe so as to take/remove a thousandth or two, and how to find (set zero) at the very edge (side) of a part with an end mill..or a grinding wheel.

 

[michiganbuck]

Nice calipers..good that you don't let everyone use them.

 

[moosesgunsmithing]

i bought a 12"dial caliper for more use in. i am figuring when i start a job on a lathe or mill that it will probably be bigger than 6" while in the workplace, so i got 12" which just means i can do even more. I just thought chnaces are my parts at work will be bigger than 6

You'll probably use them a handful of times. You definitely won't regret having them but for a beginner 6 inches is a long way to be measuring.

 

[William Lynn]

i bought a 12"dial caliper for more use in. i am figuring when i start a job on a lathe or mill that it will probably be bigger than 6" while in the workplace, so i got 12" which just means i can do even more. I just thought chnaces are my parts at work will be bigger than 6

FWIW, if the part has a critical ID or OD dimension, don't expect to get perfect readings with a caliper. I realize you're starting out in the trade and cannot have every tool needed all at once.

 

[LatheLover91106]

Fantastic! Glad to see the next generation investing in the future like this!

For calipers, that much of a gap isn't a big deal IMO. Not to say it shouldn't be better, or that you couldn't make it better (I've know guys to dress the jaws with a hone), but considering it's .001" resolution, ideally it only needs to be repeatable to the nearest 1/2 thou.

it is for sure repeatable to half a thou. its is reading coresct with a gauge block and thickness gauge. It is about 1/4 thou gap when closed so it is very small and only visible when held to a bright light...so yes it is fine my instructor said

 

[LatheLover91106]

You'll probably use them a handful of times. You definitely won't regret having them but for a beginner 6 inches is a long way to be measuring.

i understand...i just got 12 so when i have a part at work that is bigger than 6 inches i can do it....my father wa a machinist and also told me to buy 12" because he never had a part smaller than 6". Plus i will have these for the rest of my life. plus i didnt have to pay for these so i got the biggest i could get.....also ill still use them all the time at work since they can still do small measurements.

 

[William Lynn]

i understand...i just got 12 so when i have a part at work that is bigger than 6 inches i can do it....my father wa a machinist and also told me to buy 12" because he never had a part smaller than 6". Plus i will have these for the rest of my life. plus i didnt have to pay for these so i got the biggest i could get.....also ill still use them all the time at work since they can still do small measurements.

Side note, I used the shops 6 foot vernier more than I used my personal 12" dial.

 

[jccaclimber]

It seems like everyone develops some sort of preference for caliper size.
Personally I'm in the digital Mitutoyo camp, but I switch units a lot.
My preferred size is 8", biggest I can comfortably work with one hand and I used to regularly see parts just over 6".
The funny thing is that I haven't worked with parts over 4" in a couple years, but I still insist on using the 8" pair as my daily tool.
If you're happy with them and take care of them then you're all set.
I'd say 50% of the time that I see calipers that don't close there is a very slightly bent tip, but some people are also better at detecting small light gaps than others.

 

[William Lynn]

I'd say 50% of the time that I see calipers that don't close there is a very slightly bent tip, but some people are also better at detecting small light gaps than others.

Using good calipers for a scribe bugs me. If I'm watching a video and they scribe lines with them, I usually quit watching. But that's just my opinion.

 

[moosesgunsmithing]

i understand...i just got 12 so when i have a part at work that is bigger than 6 inches i can do it....my father wa a machinist and also told me to buy 12" because he never had a part smaller than 6". Plus i will have these for the rest of my life. plus i didnt have to pay for these so i got the biggest i could get.....also ill still use them all the time at work since they can still do small measurements.

I've always waited till I actually have the job in hand to buy tools I don't wish for regularly. I don't do rish jobs so waiting a day or two for the parts house to deliver has never been an issue. We all wind up doing different work so we all operate a little differently.