Talk to me about calipers.

[Justin Presson]

I need a new caliper for making folders my old piece of junk HF one died.
Im not looking to spend hundreds of dollars but more then $15 at HF.
Is a dial caliper more accurate then a digital or does it matter? What is a good one in the $50 range.
Thanks for your input.
JP

 

[KenH]

Could you squeeze in another $75 in the budget for a $125 caliper? Mitutoyo is a VERY good name in measurement instruments. This one will measure to 1/2 thou and pretty darn close. Similar to the Mitutoyo I've got. https://www.amazon.com/dp/B00IG46NL2/

Here's the same caliper for $100 shipped, "open box" type. This does have listings from China for a good bit less, but those could well be counterfeit. https://www.ebay.com/itm/362264227580?

No, a dial caliper is NOT more accurate than digital. I've got a dial caliper I've had for almost 50 yr - it was a "high dollar" caliper when new. I trust it to a couple of thou by reading close.

Here's a cheap digital caliper I've got and actually works pretty darn good. In fact, I use it most of the time rather than the "high dollar" Mitutoyo because it works so well, and if I drop it, no biggie.
https://www.amazon.com/dp/B004HLUEVI/ All for $12 shipped.

 

[EdCaffreyMS]

I've purchase a lot of different calipers over the years. Like most, I started with cheaper ones, and kept inching my way up until I came across Mitutoyo.

Personally I have one of each of the following.....

https://www.amazon.com/Mitutoyo-500...057&sr=8-3&keywords=mitutoyo+digital+calipers

and

https://www.amazon.com/Mitutoyo-ABS...057&sr=8-6&keywords=mitutoyo+digital+calipers

Both are about double the $50 range you listed, but I don't think there is anything out there in the $50 range that is durable and accurate.

My favorite digital caliper is from Starrett 721, but it's pretty spendy.... a tad over $300... but where most digital calipers read to 3 digits pas the decimal point, the Starrett reads 4 digits past the decimal...... I couldn't find them online, but the Starrett is my "go to" when building folders..... that extra place past the decimal just drives me to be more accurate. (It's the bottom one in the pic)

 

[BrandantR]

As you know, I build mostly folders and in doing so, I use my micrometer much more than I use my vernier calipers when I'm measuring the small precision parts for my knives. I believe that either measuring device will work just fine, but for me, the micrometer is the most convenient. I mount the micrometer in my small bench vise which leaves my hands free to hold the part like shown in the pic below. It's just another method for you to consider.

 

[Smallshop]

Use a digital...they are less affected by grit. Dials are a tiny gear and rack which clog easy. Cheap Chinese are more than accurate enough for knife work. I used to only buy Etalons which are Swiss and nice feel...but really a caliper is not considered a highly accurate inspection tool. For anything under a thou or two you should be using a micrometer anyways. Also be careful using a vise to hold a mike...easy to tweak the frame and damage the mic or cause a mis-read of the mic..Brandant was in no danger as his mic has plastic side panels...not all mics do... You can buy cheap micrometer holders (under $20)which almost always have rubber lined jaws for the obvious reason.

https://www.amazon.com/HFS-PRECISIO...=1522175825&sr=8-1&keywords=micrometer+holder

 

[Justin Presson]

Thank you all for taking the time to comment and post links.

So for the guys that make folders is a micrometer the preffered way to measure to make sure the spring is same thickness as blade tang or slightly bigger if Im using PB washers?

 

[KenH]

Doesn't matter what you're making, if you want a measurement to the .001" (or less) a micrometer is the ONLY way to be sure. Calipers are normally for .001" to .002". With that said, those new digital calipers are spec'd to be 1/2 thou. To me, it just seems easier to get more accurate measurements with a mic than with calipers. For handy easy "rough" measurements I'll grab the calipers, but when an "accurate" measurement is desired, as Ted says, go with a mic every time.

 

[BrandantR]

Calipers are great for getting things close, but when I want accuracy to the 0.001", I trust my micrometer.

When I'm ready to dial in all of my parts, I measure the thickness of my blade and washers, add 0.002" for clearance and grind my bushing and spacer to that thickness for my liner locks. A micrometer gives me the kind of precision that I need for a nice, tight fit.

 

[BossDog]

I use both a caliper and micrometer. The caliper gets used for rough thickness checks - that's it. The micrometer gets used for precision measuring. I've heard of more than one machine shop that doesn't allow calipers because they can be so far off depending on the user, the material and technique. Still a quality caliper is a great tool to have. I spent around $125 on a dial Starret after going through several cheap ones and dozens of dead batteries. My digital micrometer measures accurately to .0002", the caliper I would trust only to +/- .002" , maybe a thou on a round part, if that.

 

[Smallshop]

Guys...if I had to buy something and was on a tight budget I'd do this...one of each...$6.00 under the budget for both!

https://www.amazon.com/Fowler-52-22...TF8&qid=1522252108&sr=1-8&keywords=micrometer

https://www.amazon.com/gp/product/B076MSB985/ref=ox_sc_sfl_title_1?ie=UTF8&psc=1&smid=A7C1L06GA19WN

When working as a tool & gage maker I used to hate using my tools in the grind room...sometimes you would be surface grinding for a week at a wack on a big gage...I bought a cheap chinese mic and a Mititoyo vernier caliper...one really wasn't affected by grit as there was only a slide action...the mic was cheap so didn't care...that was over 30 years ago and i still have both and both are still accurate...('cept I can't read the vernier anymore...lol...well with my 3.25 specs i can...) But I kept 'em clean and wiped 'em before use, etc, etc,.

I think Chinese inspection tools have improved since then and American tools have declined (only a bit). And Japanese (mititoyo basically...lol) are fabulous.(because of $$ compared to American) I'd put anything Mititoyo against Starrett ANY DAY. I have both. My electronic 0-1 Mititoyo has seen a lot of use and is still accurate. I can mic any gage block and it reads right to the .0001.

Fowler tools used to be American made...they are all made in china and india but seem to have held decent quality control...Though I bought some black face drop indicators from Fowler some years back that felt pretty cheaply made. You know, I buy most things online...and If they do not provide good clear pics I don't buy. I scruntinize the pics closely and usually am happy with what I get.

The only downside to Mititoyo is that over the years their reputation has grown so well that their price has crept up....lol.

Hope this helps....

 

[Darrin Sanders]

When buying precision tools, buy the best you can get and you'll only cry once and I agree that Mitutoyo is the best I've ever used. If you can't afford Mitutoyo buy another set from HF until you can. Digital isn't necessary but they are nice. I also agree that calipers are only for "rough" measurements and when you really wanna measure something grab the micrometer. You can shop around and find the 4" mitutoyo calipers for less than $100. That's what I use 95% of the time but I have several. My neighbor GAVE me a brand new set of 18" Mitutoyo digital calipers about 2 years ago.

 

[Justin Presson]

Thank you all for the education on calipers and micrometers, I never knew the accuracy difference. Sounds like I need one of each and ultimately probably a nice micrometer for folder work and calipers for fixed blades.
Some good info guys!!

 

[Drew Riley]

I've used several brands of calipers from dollar store quality, to top of the line, and the best value I've yet to find are made by iGaging:

https://www.amazon.com/iGaging-ABSO...pID=51r2J68iW3L&preST=_SY300_QL70_&dpSrc=srch

Pros:
Don't have to worry about zeroing every time you use them
Battery lasts a ridiculously long time, whether you leave it on or not
Feel as good as calipers I've used that cost 5x more
If you drop them or break them, they're relatively cheap to replace

Cons:
I really don't have anything bad to say about them.
If you're looking for a resolution of .0001, these are only good for every .0005, IIRC, but if you need to measure better than that, you're using the wrong tool anyway.

You'd be hard pressed to convince me that a set of Starrett or Mitutoyo calipers are worth the extra $1-200, especially for our applications. You might get just a small degree of additional smoothness (arguable I'm sure), and there's a slight chance that the more expensive calipers MIGHT be made of a harder or more durable steel, if you do a lot of scribing, though I must say, I scribe with these a lot, including on a powered lathe, and I've yet to notice any significant wear. The jaws are infact hardened, and seem to hold up very well.

I also have their digital mic, and while I have replaced the battery on it a little more often, for the money, it's really hard to beat as well.

 

[Darrin Sanders]

I've seen that brand before. IIRC it was on the little machine shop site. Good to know that they're decent quality. I may give em a spin if I ever need another set.

 

[Smallshop]

I've used several brands of calipers from dollar store quality, to top of the line, and the best value I've yet to find are made by iGaging:

https://www.amazon.com/iGaging-ABSOLUTE-Digital-Electronic-Caliper/dp/B00INL0BTS/ref=sr_1_3?ie=UTF8&qid=1522466003&sr=8-3&keywords=igaging+absolute+origin+0-6"+digital+electronic+caliper&dpID=51r2J68iW3L&preST=_SY300_QL70_&dpSrc=srch

Pros:
Don't have to worry about zeroing every time you use them
Battery lasts a ridiculously long time, whether you leave it on or not
Feel as good as calipers I've used that cost 5x more
If you drop them or break them, they're relatively cheap to replace

Cons:
I really don't have anything bad to say about them.
If you're looking for a resolution of .0001, these are only good for every .0005, IIRC, but if you need to measure better than that, you're using the wrong tool anyway.

You'd be hard pressed to convince me that a set of Starrett or Mitutoyo calipers are worth the extra $1-200, especially for our applications. You might get just a small degree of additional smoothness (arguable I'm sure), and there's a slight chance that the more expensive calipers MIGHT be made of a harder or more durable steel, if you do a lot of scribing, though I must say, I scribe with these a lot, including on a powered lathe, and I've yet to notice any significant wear. The jaws are infact hardened, and seem to hold up very well.

I also have their digital mic, and while I have replaced the battery on it a little more often, for the money, it's really hard to beat as well.

Good info! And I notice that they offer 4" calipers...one of the handiest sizes there is...they fit a pocket with out falling out!!

 

[EdCaffreyMS]

^^^ For that kind of money it would be worth giving those calipers a chance!

Since we're talking about measuring devices, if you build folders and use bearings (IE: Flippers), a digital depth gauge is worth owning too. Over time I've learned to NOT trust the DRO on my mill when it comes to counterboring bearing pockets..... I've learned to stop a few thousandths short of my target depth on bearing pockets, and grab the digital depth gauge....... I can always take a bit more, but once it's gone, I can never put it back!

 

[KenH]

But I just have no need to wast $125 on a caliper. No knifemaker does!

I agree with you 100% - I've got one of those $100+ Mitutoyo calipers and it's really nice. BUT - since I've been known to drop tools while using them on the concrete floor, the Mitutoyo tends to stay in drawer while I use the cheap digital calipers. When I need something more accurate than calipers (.002") I'll be using a micrometer.

 

[Smallshop]

Over time I've learned to NOT trust the DRO on my mill when it comes to counterboring bearing pockets..... I've learned to stop a few thousandths short of my target depth on bearing pockets, and grab the digital depth gauge....... I can always take a bit more, but once it's gone, I can never put it back!

Great advise! I do this with anything I can...lathe,mill,drill press, etc. there is always a little "drive-line lash" which can over cut or under cut....best to sneak up on the fussy stuff...lol

 

[EdCaffreyMS]

Just a follow up..... after checking out the 4" calipers that AR & Ted posted the link to..... I decided to order it just to see what the quality is..... surprisingly GOOD! It arrived this morning, just in time for working on a folder....... I compared them head to head with my "high dollar" Starrett, and for the money, they are an awesome bargain in calipers! I did notice that they require me to "reset" more often than the expensive calipers, but for $40 you can't beat them! I can see another couple of these in the future! Thanks AR & Ted!!!

 

[Drew Riley]

Just a follow up..... after checking out the 4" calipers that AR & Ted posted the link to..... I decided to order it just to see what the quality is..... surprisingly GOOD! It arrived this morning, just in time for working on a folder....... I compared them head to head with my "high dollar" Starrett, and for the money, they are an awesome bargain in calipers! I did notice that they require me to "reset" more often than the expensive calipers, but for $40 you can't beat them! I can see another couple of these in the future! Thanks AR & Ted!!!

Did you get the "Absolute Origin" calipers? I'm not sure I've ever had to reset my 6", as they always go back to zero and read where they should. Anytime I don't get zero at closed position, there's always some dust or grit between the jaws.
I've actually tried to "lose" the origin by opening and closing them really fast, and I've never been able to.