Outside Micrometer 3-4" Measuring Range,0.0001" Graduation for Machinists,Professional Precision Tool for Accurate Measurements

For a 3-4" micrometer, this is a very inexpensive instrument. It worked OK for my purposes (cylinder bore measurement using a telescoping gauge), but I had some difficulty checking the calibration with the included 3" standard. I ended up using a precision 1-2-3 block to check the factory calibration, which was spot on, and forged ahead with my measurements.As near as I can tell, the calibration problem was caused by the axes of the spindle and anvil being offset by about 1mm. In the photos, you can see that one end of the calibration standard is aligned perfectly with the spindle and the other end is offset relative to the anvil while the calibration is near perfect.

I bought this set a year ago, and used the 1" and 3" micrometers a few times, with reasonable success.Today, I tried to use the 4" micrometer to set a dial bore gage to measure a pair of motorcycle cylinders.When I measured the cylinders the gage showed that they were between .0025. and .0045 above the service limit, and needed to be replaced.That seemed odd since there was no wear ridge, and the pistons, and cylinders didn't really look like they were excessively worn, so went back to the mic and checked the dial bore gage.It was exactly where I set it, at 3.701"At this point in time, I grabbed the calibration standards that came with the micrometer.The 3" measured 3.0000 and the 4" measured 3.9999.I reset the gage to micrometer and checked the measurements again, and once again the cylinders appeared to be worn beyond their service limit.In an act of frustration and desperation, I grabbed a dial caliper and checked the set up on the micrometer.The micrometer was set to 3.701, and the caliper reading was off almost .005!I confirmed this with 3 different calipers, including a mitutoyo.When I reset the dial bore gage with my calipers, and measured the cylinders again, I measured the light wear that I had expected, and determined that the cylinders were within the service limit, and could be reused.If I had not questioned the measument, I would have needlessly scrapped, and replaced over $1200 in parts.Not to mention the hour I wasted trying to validate the original measurement.I would NOT recommend these micrometers to anyone.

I'm a 23 Year CNC Machinist and I have bought a lot of Brown & Sharp, Fowler, Starrett, Etc brand tools and I must say that the quality of this $35.00 2-3 In. Mic is equal to a high dollar Starrett Mic. I was totally surprised, I figured that they would be junk but were not. Nice ratchet stop and calibrated to exact Zero when I checked them before use. Don't hesitate if your looking for a starrett Twin.

I was looking for a larger (2 to 3") micrometer to add to the tool box and saw this one on Amazon. I was surprised at the price so I ordered it. I am well pleased with the feel and accuracy of the micrometer. Sure I could have spent another $125 and purchased a "Name Brand" item but for my purposes this will work for me. I liked it so much I bought the 3 to 4 inch model as well. As with all precision tools, take care when handling and measuring your work.

for the home hobbiest it's perfect, for a weekend engine builder it will do. The mic's are all off by .0001 + or - , if your gonna use them like me probably 2 or 3 times a year then yes well worth it. If you want better precision then you gotta spend $1000 or more for higher end quality. These get them job done and they are what I needed to measure tolerances on a smal block chevy

Product looks like it's okay but it arrived in so many pieces. The wooden box was broken and all of the products inside of it were scattered all over the bottom of the shipping box. Not sure how the product works yet but not great first impressions.

Nice micrometer. Comparable to much higher priced devices.

Nothing much to say about this one, really. Looks good, measures good, isn't a Starrett, but is well built and feels good. Happy camper!