Micrometer purchase

[nuclearcricket]

I am a retired tool make, in my work life I used micrometers a lot. I have several Starrette micrometers that I used as my "milling" mikes. When it came time to do the precision grinding of parts I purchased and used Swiss made Etalon micrometers. They are expensive but very good. Before I retired from the work force I started to set up a small shop at home and needed measuring tools there. I purchased micrometers from CDCO machine. They are made in china. I checked them with guage blocks and made any adjustments needed and they have worked very well for me over the years. They have a very solid feel in the hand, are smooth and accurate. I also have a 4" dial caliper I picked up from Grizzly. It has turned out to be very handy and also when checked with blocks its right on the money. I also have a set of Metric micrometers that I don't use but they also came from China and are as accurate as all the rest of my tools. It pays to buy good tools and it especially pays to check or have them checked for accuracy. One set of vineirr calipers I purchased were not marked right and were not accurate and they got sent back.
Good tools are well worth the investment. Most of the foreign made tools are of good quality and will server the average home user very well over the years with a little care, cleaning and lubing. A good oil like Starette tool and instrument oil is good to keep around.
Sam

[country gent]

The last tool room I worked in was also ISO 9001 certified so our personal measuring tools were certified every year by gauge and layout. This included our standards for them. One thing to get in the habit of is to check the tool when you pick it up to make sure its zeroed out. Calipers wipe the jaws and close, if not reading zero see why and rezero. Mics the same. Starrett instrument oil is very good it dosnt gum thicken or affect the tools feel. Only a very light coat is needed.
When I had my tools certified the company replaced 2 federal finger indicators do to flat spots on the tips ( the fingers were no longer available to be replaced). Also the environment will affect the zero, temp swings, dusty, working on machines with coolants, and such will all affect zeros over time. Setting the tool on a machine the vibrations can have an affect. Never store a mic completely closed or open. Keep them clean and oiled. Same with calipers.

Calipers mostly failed inspection not because the inside jaws werent accurate but because 1 of the 4 sets of jaws didnt match to the others. Most dial and digital calipers have 4 means of measuring inside, outside, and depth normally 2 ways 1) From front edge to movable jaw and 2) the depth rod to base of beam. All of these have to be zero to pass. On digital calipers it is easy enough to zero one set of jaws as they can be zeroed at any point on the scale.Dials can be tricky to do this.