Starrett 120A-6 White Dial Calipers, Hardened Stainless Steel, 0-6" Range, .001" Graduations

by Starrett

Product Features

• Precise dial graduations of 0.001", with one revolution equivalent to 0.100"
• Thumb-operated fine adjustment roll allows for one-hand use
• Lock screw holds the sliding jaw in position, ensuring a consistent measurement
• Rack teeth point down to keep foreign matter from clogging the gear, which helps prevent measurement error
• Hardened stainless steel bar, measuring surfaces, rack, gears, and depth rod for accuracy and long life

Product Details

• Product Dimensions: 1 x 1 x 9.5 inches ; 1.5 pounds
• Shipping Weight: 4 pounds (View shipping rates and policies)
• Shipping: This item is also available for shipping to select countries outside the U.S.
• ASIN: B00002254I
• California residents: Click here for Proposition 65 warning.
• Item model number: 120A-6
• Average Customer Review: 3.4 out of 5 stars  See all reviews (19 customer reviews)
• Amazon Best Sellers Rank: #4,525 in Industrial & Scientific (See Top 100 in Industrial & Scientific)
  • #36 in Industrial & Scientific > Measurement & Inspection Products > Calipers > Dial Calipers

Product Description

The Starrett 120A-6 dial caliper measures 0 to 6 inches with 0.001” accuracy. This handy measuring tool allows for reliable and accurate readings with the sharp, black graduations on the no-glare, satin-finished bar, crisp lines on the white dial face, and knife edge contacts for inside and outside measurements.

One full revolution of the dial is equivalent to 0.100”. The jaw depths on this caliper are approximately 1-1/2” for the outside measuring jaws and 5/8" on the inside measuring jaws. The knife-edge contacts can be used to scribe parallel lines on the workpiece. This caliper can be used with one hand through operating the fine adjustment roll with the thumb. The lock screw locks the dial bezel and holds the sliding jaw in position. The depth rod is integrated into the rack of the caliper, unlike many calipers which offer a detachable depth rod, or none at all. The hardened stainless steel components, including the bar, measuring surfaces, rack, gears, and depth rod, offer corrosion resistance, increased accuracy, and long life. Positive split gear anti-backlash control offers increased accuracy over standard gear configurations. Backlash is the amount of clearance between mated gear teeth in the caliper controls, which prevents the gear teeth from jamming. It is undesirable to have much backlash due to the lack of precision offered by the increased amount of play between gears. Certain gear designs can minimize or eliminate backlash; split gear systems actually split the gear into two gears, each half as thick as the original gear. One of these gears is then fixed to the shaft while the other gear is allowed to turn. The free-turning gear is connected to coil springs that rotate it until all backlash in the control system has been eliminated. The rack teeth point down to keep foreign matter from clogging the gear operations. This prevents measurement errors where metal chips could interfere with proper caliper operation.

Calipers measure the distance between two opposing sides of an object. They make inside, outside, depth, or step measurements, according to their type. Calipers are commonly used in architecture, metalworking, mechanical engineering, machining, manufacturing, carpentry, and medicine. The simplest calipers have two legs to mark the two points and require a ruler to take the measurement. More complex calipers use two sets of jaws instead of legs and have up to two graduated scales. Vernier, dial, and digital calipers give direct and accurate readings and are functionally identical, having a calibrated scale with a fixed jaw, and another jaw with a movable pointer that slides along the scale. The vernier caliper has a scale sliding parallel to the main scale for an additional, fractional reading to improve measurement precision. The dial caliper has a circular dial with a pointer on a toothed gear rack replacing the second vernier scale. As with the vernier, this second measurement is added to the reading from the main scale to obtain the result. The dial caliper is used also for measuring size differential between two objects. The digital caliper takes the same sort of differential measurements as the dial caliper by zeroing the display at any point along the slide, with an LCD (replacing the dial) that displays a single, easily read value in both English and metric units. Some digital calipers can hold data readings between measurements and send them to data collection devices.

The L. S. Starrett Company was founded in 1880, originally manufacturing bench vises, squares, and other tools. They acquired other companies throughout the years, expanding their services into making precision measurement instruments and tools, such as calipers, micrometers, saw blades, and gauges. Starrett is headquartered in Athol, Massachusetts and they have manufacturing facilities in Brazil, the United Kingdom, China, and other locations.

Customer Reviews

Most Helpful Customer Reviews

34 of 34 people found the following review helpful:

5.0 out of 5 stars "Heirloom "needs a bit of qualifying!, January 24, 2001

By 

Kevin Bentz - See all my reviews

This review is from: Starrett 120A-6 White Dial Calipers, Hardened Stainless Steel, 0-6" Range, .001" Graduations

One of the reviewers referred to this caliper as being "heirloom quality". I feel that statement needs a bit of qualifying.

Starrett has recently (within the past couple of years) made some changes to this caliper. I'll let you be the judge as to whether it was a good move. I should preface this by saying that I own several Starrett tools and have plans to add more to my chest (my wallet permitting).

The first change that I'll speak to is with the dial housing. It has gone from being made from metal to plastic. I spoke w/a tech rep at Starrett who told me that It was a cost cutting measure as well as an attempt to make all the dials in their product line universal. He also said that he has fielded several customer complaints regarding this change. I have both versions of this caliper and the one with the plastic dial does not meet my expectations of "heirloom quality". It is a fine caliper but the plastic on this instrument detracts from the reputation for quality that Starrett has developed. However, the metal dial version of this tool, IMHO, embodies the qualities that Starrett is known for. I should also say that there is no functional difference, that I can find, between the two calipers.

The other refinements (of the plastic dial version) are merely asthetic. The jaws have a slightly different profile and the depth rod is slightly thicker. Nothing that would provide anything better functionally.

I hope that Starrett will return to producing calipers with a metal dial housing. If you can get your hands on one of these, then you will really have something that is "heirloom quality"

21 of 21 people found the following review helpful:

4.0 out of 5 stars I also feel that plastic has no place on a caliper, May 3, 2001

By 

"srightnar" - See all my reviews

This review is from: Starrett 120A-6 White Dial Calipers, Hardened Stainless Steel, 0-6" Range, .001" Graduations

I practically grew up in a machine shop with a father that would only buy top quality tools. While I feel that Starret is still a top quality tool I would have to agree with the previous reviewer about the bad decission to change to the plastic dial.That one little detail knocked this tool down from 5 stars to 4 stars. I would have been happy to pay the extra 10 bucks for a metal dial housing. While this may sound silly but this little detail would have cost them a sale if I compaired it side by side with Brown&Sharpe and Mitutoyo and either one had a metal dial housing. Also what happened to quality cases? When I think back to my dads tool boxes (20 yrs ago) all the tools seemed to have wooden finger joined boxes now you get plastic boxes ( not even plastic that is well designed). Finally I would like to say all things being considered this is a very good tool and I would recomend it.

32 of 35 people found the following review helpful:

3.0 out of 5 stars Disappointing, July 8, 2003

By 

Gary Yuen (Henderson, NV) - See all my reviews

This review is from: Starrett 120A-6 White Dial Calipers, Hardened Stainless Steel, 0-6" Range, .001" Graduations

Starrett instruments for years have had a well deserved reputation for quality. With that in mind, I ordered their 120A-6 caliper. Upon receiving it, I immediately noticed the dial was zeroed incorrectly in the 9 o'clock position. Either this caliper was damaged in transit to me, or it was assembled incorrectly.

I contacted Amazon regarding this and the service offered for replacement was fast and courteous. When my new replacement Starrett caliper arrived, I discovered it also had the dial set incorrectly at the 9 o'clock position. This led me to believe that both of the calipers had been assembled incorrectly at the factory.

My next step was to contact Starrett regarding this. They offered to adjust/repair my caliper, all the time still touting their quality and 100% inspection policy on everything leaving their factory, but as I packaged it up to ship to them, I reflected on not just the assembly of this product, but the fact that parts of it (the dial housing) were of inexpensive plastic, as noted by other reviewers. In my opinion, this is definitely not in keeping with a set of ... calipers.

I wound up shipping the Starrett back to Amazon for a refund. I wish Amazon would offer another brand of high end calipers for sale as I found the Starrett to be disappointing, especially so when considering Starrett is the only American made brand available.