Once you figure out how they are read it works great.I used it to take some measurements to have a machinist make some parts for me. He made the parts for me and they fit perfectly. So I would say the measurements were accurate.

A cost effective quick check micrometer . I only use few times a year and it suits my needs well

Good quality micrometer

The instructions provided for alignment are useless, so I am including corrected instructions. First though is the anatomy in the terms used by General Tools where available, going from left to right when frame and anvil are on the left. 1 Frame, 2 Anvil (stationary measurement surface), 3 Spindle (movable rod with measurement surface), 4 Lock, 5 Barrel (stationary sleeve with numbers and graduation lines), 6 Thimble (rotates to adjust spindle position) 7 Ratchet Knob (used for final closure of spindle to anvil or surface of measured object)Calibration Procedure.Fully open the lock. Back off the thimble until you can see the slotted-head setscrew on the barrel. Loosen the setscrew 1/8th to 1/4th turn with a 2mm flat-blade screwdriver (jeweler’s screwdriver). Slowly close the spindle onto the anvil using the ratchet knob until you get three clicks. Use the larger section of the supplied pin spanner wrench to turn the barrel until the horizontal mark on the barrel matches the "0" mark on the thimble. Back off the thimble again to reveal the setscrew on the barrel, and tighten it.Initial CalibrationIt appears that General Instruments Micrometer is not initially calibrated. The two I checked were both reading about 1.5 mils when the reading should have been zero. On one the setscrew on the barrel had not been tightened.How to Read the MicrometerFor simple description, I will use units of mils (one mil is one thousandth of an inch, 0.001”). To convert from mils to inches, divide the number of mils by 1000. Each major (numbered) graduation on the barrel equals one hundred mils (.100”). Each minor (un-numbered) graduation line on the barrel equals twenty five mils (.025”). Each major graduation line on the thimble equals one mil (.001”); minor graduations are ½ mil (.0005”).For easy reading in mils (thousandths of an inch), do the following. Take the product of 100 times the number of the highest visible major graduation line on the barrel, and add the product of 25 times the number of minor graduation lines between the major one and the thimble. Then add the number of the major thimble graduation line which coincides with the horizontal line of barrel. Note that special care is required when either the major or miner graduation line of the barrel is just visible at the edge of the thimble. For example, if the thimble reads 20, the barrel line just visible at the thimble edge should NOT BE read or counted, because it will not be valid until a thimble reading of 0 past the present barrel line (same as 25 past the previous barrel line) has been reached.Accuracy Error Due to FrictionIf the frictional torque is a significant percentage of the torque provided by turning of the ratchet knob, either the calibration will be non-repeatable and thus inaccurate, or some measurement distances might produce non-repeatable and thus inaccurate results or both. The first instrument I had was shipped without adequate protection in a large container with two heaver, unrestrained items. The micrometer had escaped from its blister pack, and I assume taken a beating. It had several distances that had enough friction to cause ratcheting as the ratchet knob was turned. When that happens, measurement to one mil accuracy is not possible. Cleaning the threads gave some improvement, but still, checking the calibration would result in a variation of typically 1.5 mils. I exchanged it.The next micrometer was shipped in a standard shipping envelope with a very thin layer of bubble padding on the inside of the envelope. This packaging might provide some protection from the shock of dropping or throwing the package but none from the pressure of other objects pressing against it. This micrometer arrived with the thimble rubbing against the barrel. That caused the ratchet to click at several locations. I was able to correct the misalignment of the thimble by careful correction using only my fingers. This micrometer now repeats the calibration check within 1/4th of a mil. This instrument is likely to meet the specified accuracy of 1 mil.As received, both this instrument and the first one had so much friction as to render the ratchet knob useless. Using only the thimble for closing the spindle might have achieved an accuracy of two or three mils. The fact that I was able to correct the misaligned thimble problem with moderate finger pressure is an indication of the vulnerability of this instrument to shipping stresses. The blister pack is not appropriate protection to guarantee this instrument will be capable of one mil accuracy after shipping and handling.CosmeticsOn the micrometer I have, the threaded holes for mounting the plastic plates each side of the frame are poorly located and apparently angled. The plastic plates are both off-center, but one is so far off that it extends past the frame. I don’t think this problem was as bad on the first micrometer I checked.

Zeroes consistently and produced reasonable and consistent readings on ball bearings I had lying around. This was way nicer than I expected for a cheap tool. Mine came perfectly zeroed.

As described

I’m pleased for what I needed it for.

Received my micrometer yesterday, the quality is not that good. I've seen better tools out of China.1. It looks different from the Amazon picture. There are no conversion numbers printed on the frame. Instead, there are two black plastic pieces covering the frame. The plastic covering are off center, making it look bad. I tried to unscrew the plastic cover hoping to center it better, one hole has a large opening that can be adjusted, the other hole is drilled on the frame and cannot be adjusted. The hole was simply not drilled carefully.2. The Spindle and Anvil does not line up perfectly. The Anvil looks a bit angled (up) compare to the direction of the spindle. They do meet flush with one another, but the two circles are not lined up correctly.3. The movement of the Thimble is not smooth. It feels like there are some dirt/particles in there. I moved the thimble back and forth all the way a few times, and there are still multiple spots where I can feel some toughness when it moves.4. It came out of adjustment (.002" off). The instruction that came with the unit for adjustment is WRONG. The included hardware is for taking off the friction stop, which is not related to the adjustment at all. Looking through the Amazon reviews, I figured it out. It's a simple flat screw on the barrel that becomes visible after you back off the thimble a bit. You can then rotate/slide the barrel. I was able to adjust 0 properly.5. Measurements are not always consistent (0" or otherwise). Even before adjustment, the 0 position seems to deviate by 2-4 thimble positions (using the friction stop). After adjustment, it still deviates somewhat.I learned about micrometers in my beginning auto class. Ironically, the ones that are being passed out in class, made in the US and 10+ years old, feels much better made. The movements are smooth, everything looks aligned, and zeros pretty well with hardly any deviations. Having used those "old" micrometers, the quality of this new one seems pathetic in comparison. I've seen much better tools out of China.One interesting note, the marks on the thimble are down to half of .001". One rotation of the thimble is .025", but there are 50 marks on the thimble. So it can measure down to .0005". I did some measurements (papers, hair, etc), it works OK, some slight deviations from measurement to measurement. It will probably work OK for basic measurements, but anyone looking for a decent quality micrometer will be disappointed.

Presition

Works well and seems to be decent quality.

Received on time, needed this tool for a specific job at home workshop, anvil was loose giving an inconsistent reading, which in my case was not acceptable. Although this one was defective, I may still try another, may just have been a lemon, other than that the tool would have done me just fine.

Se siente de buena calidad y es bastante preciso para el precio, la verdad me gustó mucho, habría que ver que tan duradero es.

Buen producto, le falta calidad