General Tools 102 0-Inch to 1-Inch .001-Inch Graduation Micrometer

This tiny microphone is a great deal. I use it on a regular basis and find it to be perfectly adequate for general machine work or sizing replacement parts. It's within a couple of tenths right out of the box, so I'm confident it'll suffice for most purposes. I used to work as a machinist and had to use more expensive microphones, but this one does the job for pennies.

Thea Castillo

| May 01, 2021

My micrometer arrived yesterday, but the quality isn't great. China has better tools, in my opinion. 1. br>br> It does not appear to be the same as the Amazon image. The frame isn't marked with any conversion numbers. The frame is instead covered by two black plastic pieces. The plastic covering is off-center, giving it a shabby appearance. I attempted to unscrew the plastic cover in the hopes of better centering it; one hole has a large opening that can be adjusted, while the other is drilled into the frame and cannot be adjusted. Simply put, the hole was not carefully drilled. 2. br>br>1. br>br>br>br>br>br The Anvil and the Spindle are not perfectly aligned. In comparison to the spindle's direction, the Anvil appears to be angled (up). They do meet flush, but the two circles are not aligned properly. 3. br>br>4. br>br>5. br>br>6. The Thimble moves in a jerky manner. There appears to be dirt/particles present. I moved the thimble all the way back and forth a few times, and there are still a few places where I can feel some resistance when it moves. 4. br>br> It emerged from the adjusting process (. Off by 002"). The unit's adjustment instructions are incorrect. The hardware that comes with the kit is for removing the friction stop, which has nothing to do with the adjustment. I figured it out after looking at the Amazon reviews. It's just a plain flat screw on the barrel that becomes visible once you back off the thimble a little. The barrel can now be rotated or slid. I was able to set 0 to the correct value. 5. br>br> Measurements aren't always consistent, whether they're in inches or not. Even before any adjustments, the 0 position appears to be 2-degrees off. (Using the friction stop) four thimble positions Even after adjusting, it still deviates slightly. br>br>In my first auto class, I learned about micrometers. Ironically, the ones handed out in class, which are made in the United States and are ten years old, appear to be much better made. The movements are smooth, everything appears to be in place, and the zeroing is fairly accurate with few deviations. After using those "old" micrometers, the quality of this new one appears to be abysmal. China produces far superior tools. br>br>One thing to note is that the thimble's marks have been reduced to half their original size. 001". A single thimble rotation equals. The thimble has 50 marks, despite being 025". As a result, it's possible to get it down to. 0005". I took some measurements (papers, hair, etc. ) and it seems to work fine, though there are some minor differences between measurements. It will probably suffice for basic measurements, but it will disappoint anyone looking for a high-quality micrometer.

Rafael Leonard

| Dec 09, 2021

There isn't much I can say. You get what you pay for, as I previously stated. For the time being, this will suffice. The calculation was incorrect. I did my best to fix it, but it was still a little off. It's possible that I'll return.

Mccoy Shelton

| May 17, 2021

Because the alignment instructions provided are useless, I've included my own. However, when the frame and anvil are on the left, the anatomy is described in the terms used by General Tools, which goes from left to right. br>Calibration Procedure: 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) br>Fully unlock the door. Return the thimble to its original position until you can see the slotted-in thimble. The barrel's head setscrews on. Using a 2mm flat-head screwdriver, loosen the setscrew 1/8 to 1/4 turn. screwdriver with a blade (jeweler's screwdriver) Close the spindle onto the anvil slowly with the ratchet knob until three clicks are heard. Turn the barrel until the horizontal mark on the barrel matches the "0" mark on the thimble with the larger section of the supplied pin spanner wrench. Removing the thimble reveals the setscrew on the barrel, which you should tighten. br>Initial Calibrationbr>It appears that the General Instruments Micrometer was not calibrated at the time of purchase. Both of the ones I checked were reading around 1. The reading should have been zero, but it was 5 mils. The barrel's setscrew had not been tightened on one of them. br>How to Read a Micrometerbr>I'll use mils as a unit of measurement (one mil equals one thousandth of an inch, or 0. 01 inch). 001”). Divide the number of mils by 1000 to convert it to inches. Each of the barrel's major (numbered) graduations is one hundred mils (. 100”). Each unimportant (minor) The graduation line on the barrel (which is numbered) equals twenty-five mils (. 025”). Each of the thimble's major graduation lines is one mil (. 001”); The smallest graduations are 12 mil (. 0005”). br>Do the following to read mils (thousandths of an inch) easily. Add the product of 100 times the number of minor graduation lines between the major one and the thimble to the product of 25 times the number of major graduation lines on the barrel. Then multiply by the number of the major thimble graduation line, which is parallel to the barrel's horizontal line. When the barrel's major or miner graduation line is visible at the thimble's edge, extra caution is required. 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 current barrel line (or 25 past the previous barrel line) is reached. br>Accuracy Error Due to Frictionbr>If the frictional torque is a significant percentage of the torque provided by turning the ratchet knob, either the calibration will be non-conformant or the calibration will be non-conformant. Some measurement distances may produce non-repeatable and thus inaccurate results, or some measurement distances may produce non-repeatable and thus inaccurate results. If the results are repeatable, they are likely to be inaccurate, or both. The first instrument I had was shipped in a large container with two other heavy, unrestrained items without adequate protection. I assumed the micrometer had gotten loose from its blister pack and taken a beating. It had a few places where there was enough friction to cause ratcheting when the ratchet knob was turned. It is impossible to measure to a one-millimeter precision when this happens. Cleaning the threads helped a little, but checking the calibration still resulted in a variation of about 1. 5 mils. I swapped it for something else. br>The next micrometer arrived in a standard shipping envelope with a thin layer of bubble padding on the inside. This packaging may offer some protection against the shock of dropping or throwing the package, but it does not provide any protection against the pressure of other objects pressing against it. The thimble on this micrometer was rubbing against the barrel when it arrived. The ratchet clicked in several places as a result of this. I was able to correct the thimble's misalignment by carefully correcting it with only my fingers. The calibration check can now be repeated within 1/4th of a mil with this micrometer. The specified accuracy of 1 mil is likely to be met by this instrument. br>As received, the ratchet knob on both this and the first instrument was useless due to excessive friction. Only using the thimble to close the spindle could have resulted in a precision of two or three mils. The fact that I was able to correct the misaligned thimble issue with only moderate finger pressure demonstrates the instrument's vulnerability to shipping stresses. The blister pack does not provide adequate protection to ensure that this instrument will maintain one-millimeter accuracy after shipping and handling. br>Cosmeticsbr>The threaded holes for mounting the plastic plates on each side of the frame on the micrometer I have are poorly located and appear to be angled. Both the plastic plates and the paper plates are faulty. One, however, is so far away from the center that it extends beyond the frame. This issue did not appear to be as severe on the first micrometer I examined.

Amos Crane

| Jun 11, 2021

102 (General Tools): A Review The General Tools Number 102 (analog) Micrometer is a useful tool to have around the house if you need to take precise measurements of external dimensions up to 1 inch in size. br>br>The only complaint I have is that the calibration instructions (on the paper backside of the plastic cover that the micrometer comes in) are misleading because they refer to a previous (slightly different) mechanica. Instead of a 'hex tool,' a small flat blade screwdriver is required to loosen the micrometer's base ring (allowing the zero adjustment to be shifted). Furthermore, the screw (to loosen for the zero adjustment calibration) isn't visible until you back-up (the instructions don't mention this). a couple of tenths of an inch off the adjusting 'thimble' (which you turn when taking measurements) br>br>Like any precision instrument, the micrometer should be handled with care (i. e. , don't drop it). Don't put it in your toolbox with screwdrivers and wrenches without protection). The package can be reused for storing the micrometer if you open it carefully (it's only held together by a couple of heavy staples).

Clara James

| Dec 14, 2021